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Introduction to Microbiology Class 10 Questions And Answers Maharashtra Board

January 6, 2025January 5, 2025 by Bhagya

Balbharti Maharashtra State Board Class 10 Science Solutions Part 2 Chapter 7 Introduction to Microbiology Notes, Textbook Exercise Important Questions and Answers.

Std 10 Science Part 2 Chapter 7 Introduction to Microbiology Question Answer Maharashtra Board

Class 10 Science Part 2 Chapter 7 Introduction to Microbiology Question Answer Maharashtra Board

Question 1.
Rewrite the following statements using correct of the options and explain the completed statements.
(gluconic acid, coagulation, amino acid, 4% acetic acid, clostridium, lactobacilli)

a. Process of ……. of milk proteins occurs due to lactic acid.
Answer:
Process of Coagulation of milk proteins occurs due to lactic acid.
Explanation: The lactobacilli are the bacteria carrying out fermentation of the milk. In this process, the lactose sugar in the milk is converted into lactic acid. This lactic acid causes coagulation of the proteins present in the milk.

b. Harmful bacteria like ………. in the intestine are destroyed due to probiotics.
Answer:
Harmful bacteria like Clostridium in the intestine are destroyed due to probiotics.
Explanation: In probiotics, there are lactobacilli which are useful. They control other bacteria present in the alimentary canal and also their metabolism. These bacteria thus stop the action of Clostridium which is a harmful bacteria.

c. Chemically, vinegar is …………
Answer:
Chemically, vinegar is 4% Acetic acid.
Explanation: Chemically vinegar is 4% acetic acid. It is a good preservative of the food and thus while using it as additive to the food, it is called vinegar.

d. Salts which can be used as supplement of calcium and iron are obtained from ……………. acid.
Answer:
Salts which can be used as supplement of calcium and iron are obtained from Gluconic acid.
Explanation: The microbe Aspergillus niger is used on the source material of glucose and corn steep liquor to produce amino acid called Gluconic acid. Gluconic acid is used for the production of minerals used as supplement for calcium and iron.

Question 2.
Match the pairs.

‘A’ group	‘B’ group
(1) Xylitol	(a) Pigment
(2) Citric acid	(b) To impart sweetness
(3) Lycopene	(c) Microbial restrictor
(4) Nycin	(d) Protein binding emulsifier
	(e) To impart acidity

[Note: In examination match the column question will ham 2 components in Column ‘A’ with 4 alternatives in Column ‘B’.]
Answer:
(1) Xylitol – To impart sweetness
(2) Citric acid – To impart acidity
(3) Lycopene – Pigment
(4) Nycin – Microbial restrictor.

Question 3.
Answer the following:
a. Which fuels can be obtained by microbial processes? Why is it necessary to increase the use of such fuels?
Answer:

Microbial anaerobic decomposition of urban agricultural and industrial waste forms the gaseous fuel in the form of methane gas.
Alcohol is another clean form of energy which is used in the form of ethanol. It is obtained by the fermentation of molasses by treating it with Saccharomyces-yeast.
By photoreduction of water with the help of bacteria, hydrogen gas is released in the process of bio-photolysis of water. This hydrogen gas is said to be the fuel of the future.
The conventional fuels are exhaustible. After few hundred years, they will be over completely. Moreover, these fossil fuels cause lot of air pollution due to emission of carbon dioxide. The fuels obtained by the microbial processes are not polluting. Therefore, it is necessary to increase the use of eco-friendly fuels.

b. How can the oil spills of rivers and oceans be cleaned?
Answer:

The oil spills in rivers or oceans are caused by crude oil or petroleum hydrocarbons.
This crude oil is highly toxic to the flora and fauna of the aquatic environment.
By using mechanical means the oil spill can be removed, but this is very difficult.
The biological way to remove this pollution is done by using culture of microbes like Pseudomonas spp. and Alcanovorax borkumensis.
They have the ability to destroy the pyridines and other chemicals present in the hydrocarbons.
These bacteria are called as hydrocarbono-clastic bacteria (HCB) which decompose the hydrocarbons and bring about the reaction of carbon with oxygen.
In the process CO₂ and water are formed. In this way the oil spills are cleaned, by releasing HCB at the place of oil spills.

c. How can the soil polluted by acid rain be made fertile again?
Answer:

The soil polluted by the acid rain is made fertile again by using bacteria.
Acidophillium spp. and Acidobacillus ferroxidens are the bacteria which have the capacity to use sulphuric acid as their energy source.
Since this sulphuric acid present in the acid rain, can be controlled by these bacteria.
In this way, bacteria can control the soil pollution occurring due to acid rain, making the soil fertile again.

d. Explain the importance of bio pesticides in organic farming.
Answer:

By using bio pesticides, soil pollution is minimized. Otherwise by using chemical pesticides and fertilizers there is large scale soil pollution.
When chemical pesticides are used in agriculture, there is contamination of soil by fluoroacetamide – like chemicals.
These are harmful to other plants, animals as well as for-human beings. They may cause skin diseases in humans.
By using bacterial and fungal toxins the pests and pathogens can be destroyed. Such toxins are directly incorporated in the plant materials.
E.g. Spinosad is a biopesticide produced as a by-product of fermentation.

e. What are the reasons for increasing the popularity of probiotic products?
Answer:

Probiotic substances are mostly milk products containing live bacteria. Such probiotics are very good for health.
The useful colonies of bacteria are produced in the alimentary canal of human beings due to the probiotics.
Probiotics decrease the population of harmful microbes like. Clostridium from our digestive tract.
The immunity is enhanced due to regular intake of probiotics in the diet.
The ill-effects of harmful substances formed during metabolic activities are reduced by the probiotics.
If someone takes the antibiotic treatment, then his or her useful intestinal bacterial flora becomes inactive or is eradicated. In such cases, probiotics restore the bacterial flora and make the person well again.

All these facts have made probiotics a popular choice for people.

f. How the bread and other products produced using baker’s yeast are nutritious?
Answer:

In order to make the bread the baker’s yeast – Saccharomyces cerevisiae is added to the flour for the fermentation process.
In commercial bakery, compressed yeast is used while in domestic settings dry, granular form of yeast is used.
The flour prepared by using commercial yeast contains various useful contents like carbohydrates, fats, proteins, various vitamins, and minerals.
The anaerobic fermentation also increases the nutritive content of the flour.
Due to this, bread and other products produced with the help of yeast become nutritive.

g. Which precautions are necessary for proper decomposition of domestic waste?
Answer:
The domestic waste should be properly segregated into biodegradable (wet waste) and non-biodegradable (dry waste). After segregation, these wastes should be stored separately into two different containers. The non-biodegradable substances should he either reused or sent for recycling. The biodegradable substances are decomposed naturally.

The decomposition process can be done at house-hold level too in a pot or a tank. This decomposition will yield a rich manure. The pot should be covered by a thin layer of soil and it should be kept in a dark but airy place.

The non-biodegradable things such as plastic articles, glass pieces, metal objects, unused 5 medicines, e-waste should never be thrown in wet wastes. The toxic substances and the insecticides if added to wet waste, will never allow the natural decomposition process. Therefore, only after taking proper precautions we can aim at proper decomposition of domestic wastes.

h. Why is it necessary to ban the use of plastic bags?
Answer:
Plastic is a non-biodegradable substance. It cannot be degraded back into its original constituents. It remains just like that for many hundreds of years. It causes solid waste pollution in any environment wherever it is thrown indiscriminately. If burnt, it releases very toxic gases. If dumped in landfills it obstructs the other decomposition processes.

If thrown in water bodies, it causes harm to aquatic life. Cattle graze on plastic unknowingly and are killed by it as it clogs inside their alimentary canal. The gutters and rain water drains get clogged due to plastic bags and this causes cities to submerge in water during heavy rains. Nowadays, the fishermen get more than half of plastic if they cast their net in the sea.

People use the plastic bags indiscriminately without any thought towards their environmental impact. There are better alternatives for plastic bags such as cloth bags which can be reused again and again. Therefore, it is absolutely necessary to ban the use of plastic bag.

Question 4.
Complete the following conceptual picture.

Answer:

Question 5.
Give scientific reasons.
a. Use of mutant strains has been increased in industrial microbiology.
Answer:

By using industrial microbiology, the commercial use of microbes is done.
In such experiments, various economic, social and environment related processes and products are included.
In this, fermentation processes are used to make bread, cheese, wines, enzymes, nutrients, etc.
Different types of antibiotics are also made by using processes of industrial microbiology.
In pollution control and solid waste management, the industrial microbiology becomes helpful.
In farming too biotechnology is used to produce BT crops.

b. Enzymes obtained by microbial process are mixed with detergents.
Answer:

When detergents are mixed with microbial enzymes, they start working more efficiently.
The cleaning process takes place at lesser temperatures.
Therefore, for better results, enzymes obtained by microbial process are mixed with detergents.

c. Microbial enzymes are used instead of chemical catalysts in chemical industry. (March 2019)
(OR)
Microbial enzymes are said to be eco-friendly.
Answer:

Microbial enzymes are active at low temperature, pH and pressure.
Due to this property, the energy is saved. The costlier erosion-proof instruments need not be used.
In enzymatic reactions, the unnecessary byproducts are not formed as the reactions are highly specific.
The expenses on purification of the product are minimized as no unnecessary products are formed.
The elimination and decomposition of waste material is avoided and enzymes can be reused again. Hence, microbial enzymes which are eco¬friendly are used in chemical industry.

Question 6.
Complete the following conceptual picture with respect to its uses. (Board’s Model Activity Sheet)

Answer:

Question 7.
Complete the following conceptual picture related to environmental management.

Answer:

Question 8.
Answer the following questions.
a. What is the role of microbes in compost production?
Answer:

Microbes can bring about natural decomposition of the organic compounds.
During the biodegradation, some bacteria andmfungi bring about such decomposition and release the inorganic constituents back into the nature.
Compost is formed in such a way by recycling process.

b. What are the benefits of mixing ethanol with petrol and diesel?
Answer:
When only diesel or petrol is used as fuel, there is increased air pollution. Morevoer, since these are non-renewable and exhaustible fuels, they will be finished in next some years. When petrol and diesel is mixed with ethanol, the proportion of CO₂, CO, and hydrocarbons which are emitted in the atmosphere becomes lesser.

The particulate pollutants which otherwise are emitted through combustion of petrol and diesel are not formed when fuels are mixed with ethanol. By adding ethanol to the fuels, the cost of expensive petrol or diesel also becomes less. The ethanol burns more efficiently hence ethanol is mixed with petrol and diesel.

c. Which plants are cultivated to obtain the fuel?
Answer:

The ethanol is obtained from wheat, maize, beet, sugarcane and molasses of sugarcane.
For biodiesel, the soybean, rapeseed, jatropa, mahua, flaxseed, mustard, sunflower, palm, jute and some types of algae are cultivated.

d. Which fuels are obtained from biomass?
Answer:
From biomass, the biogas and biodiesel are mainly obtained. The biogas is obtained from dung of cattle. The fermentation of cattle dung gives rise to methane. From methane, methanol is obtained. Ethanol is obtained from molasses of sugarcane and some other crops. In some countries, special crops are cultivated for the biodiesel.

e. How does the bread become spongy?
Answer:

When the dough for bread is prepared, the baker’s yeast – Saccharomyces cerevisiae is added to it.
This yeast carries out anaerobic fermentation.
This results in formation of CO₂ and ethanol.
The CO₂ formed tries to escape out of the flour and thus the dough rise. When such dough is baked, it produces spongy bread.

Project: (Do it your self)

Project 1.
Find the ways to implement the zero garbage system at domestic level.

Project 2.
Which are the microbes that destroy the chemical pesticides in soil?

Project 3.
Collect more information about reasons for avoiding the use of chemical pesticides.

Can you recall? (Text Book Page No. 77)

Question 1.
Which different microbes are useful to us?
Answer:
Many microbes are useful to us, such as bacteria which are used for making curds from milk, yeast used to ferment the batter of bread, bacteria used for making other milk products, bacteria and fungi used for making antibiotics. The bacteria are even used for pollution control.

Question 2.
Which different products can he produced with the help of Microbes?
Answer:
Milk products, cheese, cocoa, pickles made from vegetables, wine and other beverages, bread, probiotic substances and cattle feed are produced with the help of microbes.

Use your brain power. (Text Book Page No. 79)

Question 1.
In the earlier class, you had prepared the solution of dry yeast for observation of yeast. Which substance is prepared by its use on commercial basis?
Answer:
The commercial production of bread and other bakery products need yeast. In wine and beer making also solution of yeast is required.

(Use your brain power. (Text Book Page No. 81)

Question 1.
Food materials like cold drinks, ice creams, cakes, juices are available in various colours and flavours. Whether these colours and flavours are really derived from fruits?
Answer:
The eatables can be made directly from fruits or essence of fruits. But most of the food products purchased from markets use these colours and flavours which are derived from synthetic chemicals.

Let’s Think: (Text Book Page No. 83)

Question .1
Why is it asked to segregate wet and dry waste in each home?
Answer:
The wet waste decomposes on its own as most of the matter therein is biodegradable. This waste can be converted into manure by composting. The dry waste can be picked up by the bhangarwala or kabadiwala. This waste can be reused or recycled. Therefore, if dry and wet wastes are kept separately, the solid waste management becomes much easier.

On the contrary if everything is dumped indiscriminately, it adds to the total volume of the solid wastes. This becomes unmanageable. Therefore, to reduce the problems of solid waste management, the dry and wet waste segregation must be done at every point source. This also could fetch wealth from waste.

Question 2.
What is done with the segregated waste?
Answer:
In big cities, there is a mechanism to pick up the solid waste every day or even twice a day at some places. The segregated garbage is taken by the municipal garbage trucks at the land filling sites. Here it is buried deep in the ground. The dry waste that can be reused or recycled, is sold to the recycling units.

Question 3.
Which is most appropriate method of disposal of dry waste?
Answer:
Reuse and recycle is the most appropriate method of disposal of dry waste.

Choose the correct alternative and write its alphabet against the sub-question number:

Question 1.
Enzyme ……….. obtained from fungi is used to produce vegetarian cheese.
(a) lipase
(b) protease
(c) amylase
(d) trypsin
Answer:
(b) protease

Question 2.
Milk is subjected to ………… at the beginning to destroy unwanted microbes.
(a) pasteurization
(b) fermentation
(c) coagulation
(d) decomposition
Answer:
(a) pasteurization

Question 3.
………….. like compounds are formed due to lactobacilli that gives characteristic taste to the yoghurt.
(a) Lactose
(b) Caesin
(c) Acetyldehyde
(d) All the above
Answer:
(c) Acetyldehyde

Question 4.
Methane can be obtained by …………. decomposition of urban agricultural and industrial waste.
(a) aerobic
(b) anaerobic
(c) microbial anaerobic
(d) chemical
Answer:
(c) microbial anaerobic

Question 5.
……….. gas is considered to be the fuel of future.
(a) Hydrogen
(b) Nitrogen
(c) Methane
(d) Butane
Answer:
(a) Hydrogen

Question 6.
………. are mixed with waste materials at land-filling sites for quicker decomposition.
(a) Microbes
(b) Bioreactors
(c) Fungi
(d) Worms
Answer:
(b) Bioreactors

Question 7.
…………. bacteria decompose the xenobiotic chemicals present in sewage.
(a) Hydrocarbonoclastic
(b) Decomposing
(c) E.coli
(d) Phenol oxidizing
Answer:
(d) Phenol oxidizing

Question 8.
Microbes are used for ………… of environment polluted due to sewage.
(a) protection
(b) conservation.
(c) bioremediaiion
(d) decomposition
Answer:
(c) bioremediaiion

Question 9.
……….. is a powerful antibiotic against tuberculosis.
(a) Streptomycin
(b) Tetracycline
(c) Rifamycin
(d) Bacitracin
Answer:
(c) Rifamycin

Question 10.
Bacteria are used to clear the oil spills are called ………….. bacteria.
(a) phenol oxidizing
(b) electrolytic
(c) hydrocarbonoclastic
(d) decomposing
Answer:
(c) hydrocarbonoclastic

Question 11.
………… convert these salts of uranium into insoluble salts.
(a) Saccharomyces
(b) Thiobacillus
(c) Acidobacillus
(d) Geobacter
Answer:
(d) Geobacter

Question 12.
………….., a byproduct of fermentation is a biopesticide.
(a) Fluoroacetamide
(b) Vanillin
(c) Aspertame
(d) Spinosad
Answer:
(d) Spinosad

Question 13.
…………. beverage is obtained by fermentation of apple juice. (July ’19)
(a) Cider
(b) Wine
(c) Coffee
(d) Cocoa
Answer:
(a) Cider

Question 14.
Vinegar is the chemically ………… acid. (Board’s Model Activity Sheet)
(a) Citric
(b) Gluconic
(c) Glutamic
(d) Acetic
Answer:
(d) Acetic

Question 15.
In which of the following industries microbial enzymes are not used?
(a) Glass industry
(b) Cheese industry
(c) Tanning industry
(d) Paper industry
Answer:
(a) Glass industry

Question 16.
Citric acid used in production of beverages, toffees, chocolates is obtained by fermentation of …….. by Aspergillus niger.
(a) grapes
(b) sugar molasses
(c) apple
(d) coffee nuts
Answer:
(b) sugar molasses

Match the pairs:

Question 1.

Column ‘A’	Column ‘B’
(1) Vinegar	(a) Polylactic acid
(2) Xanthan gum	(b) Molasses
	(c) Icecreams and puddings
	(d) Acetic acid

Answer:
(1) Vinegar – Acetic acid
(2) Xanthan gum – Icecreams and puddings

Find the odd one out:

Question 1.
Lactobacillus acidophilus, Lactobacillus casei, Bifidobacterium bifidum, Streptococcus thermophilus
Answer:
Streptococcus thermophilus. (All others are bacteria producing probiotics.)

Question 2.
Lactobacillus lactis, Bifidobacterium bifidtim, Lactobacillus cremoris, Streptococcus thermophilus
Answer:
Bifidobacterium bifidum. (All others are bacteria used in cheese production.)

Question 3.
Dark chocolate, Miso soup, Wafers, Corn syrup
Answer:
Wafers. (All others are probiotic products.)

Question 4.
Vinegar, Soya sauce, Ketchup, Monosodium glutamate
Answer:
Ketchup. (All others are products prepared by microbial fermentation.)

Question 5.
Actinomycetes, Streptomyces, Nocardia, yeast
Answer:
Yeast. (All others have ability of decomposing rubber from garbage.)

Find the correlation:

Question 1.
Bread Baker’s yeast : : Soya sauce : ……….
Answer:
Bread Baker’s yeast : : Soya sauce : Aspergillus oryzae

Question 2.
Coffee : Caffea arabica : : Cocoa : …………
Answer:
Coffee : Coffea arabica : : Cocoa : Theobroma cacao

Question 3.
Oil slick : Alcanovorax : Rubber from garbage : …………
Answer:
Oil slick : Alcanovorax : Rubber from garbage : Actinomycetes

Question 4.
Conversion of metals into comounds : Thiobacilli : : Conversion of uranium salts …………
Answer:
Conversion of metals into comounds : Thiobacilli : : Conversion of uranium salts Geobacter.

Name the following:

Question 1.
Microbial enzymes.
Answer:
Oxidoreductases, transferases, hydrolases, lyases, isomerases, ligases.

Question 2.
Emulsifiers.
Answer:
Polysaccharides and glycolipids.

Question 3.
Microbe used in preparation of wine and cider.
Answer:
Saccharomyces cerevisiae.

Question 4.
Effective antibiotic against tuberculosis.
Answer:
Rifamycin.

Question 5.
Antibiotics.
Answer:
Penicillin, cephalosporins, monobactam, erythromycin, gentamycin, neomycin, streptomycin, tetracyclins, vancomycin.

Question 6.
Bacteria that use sulphuric acid as source of energy.
Answer:
Acidobacillus ferroxidens, Acidophillium spp.

Question 7.
Substance that makes biodegradable plastic.
Answer:
Polylactic acid.

Question 8.
Curd like food product made from sheep milk.
Answer:
Kefir.

Question 9.
Enzyme used to make vegetarian cheese.
Answer:
Protease.

Question 10.
Fungus used for making soya sauce.
Answer:
Aspergillus oryzae.

Complete the charts:

Question 1.

Fruit	Microbe used	Name of beverage
___________________________	___________________________	Coffee
Theobroma cacao	Candida, Hansenula, Pichia, Saccharomyces	___________________________
Grapes	___________________________	___________________________
Apple	Saccharomyces cerevisiae	___________________________

Answer:

Fruit	Microbe used	Name of beverage
Caffea arabica	Lactobacillus brevis	Coffee
Theobroma cacao	Candida, Hansenula, Pichia, Saccharomyces	Cocoa
Grapes	Saccharomyces cerevisiae	Wine
Apple	Saccharomyces cerevisiae	Cider

Question 2.

Source	Microbe	Amino acid	Use
Sugar and beet molasses, ammonia salt	___________________	___________________	Production of monosodium glutamate (Ajinomoto).
___________________	Aspergillus niger	___________________	Drinks, toffees, chocolate production.
Glucose, corn steep liquor	___________________	Gluconic acid	___________________
Molasses, corn steep liquor	Lactobacillus delbrueckii	___________________	___________________
___________________	Aspergillus itaconius	Itaconic acid	___________________

Answer:

Source	Microbe	Amino acid	Use
Sugar and beet molasses, ammonia salt	Brevibacterium, Corynobacterium	L-glutamic acid	Production of monosodium glutamate (Ajinomoto).
Sugar molasses, salt	Aspergillus niger	Citric acid	Drinks, toffees, chocolate production.
Glucose, corn steep liquor	Aspergillus niger	Gluconic acid	Production of minerals used as supplement for calcium and iron.
Molasses, corn steep liquor	Lactobacillus delbrueckii	Lactic acid	Source of nitrogen, production of vitamins.
Molasses, corn steep liquor	Aspergillus itaconius	Itaconic acid	Paper, textile, plastic industry, gum production

Question 3.

Source	Microbe	Amino acid
(1) Sugar molasses and salt	___________________	Citric acid
(2) ___________________	Lactobacillus delbrueckii	___________________
(3) Corn steep liquor	Aspergillus itaconius	___________________

Answer:

Source	Microbe	Amino acid
(1) Sugar molasses and salt	Aspergillus niger	Citric acid
(2) Molasses, corn steep liquor	Lactobacillus delbrueckii	Lactic acid
(3) Corn steep liquor	Aspergillus itaconius	Itaconic acid

Answer the following questions:

Question 1.
Which microbes are used in the baking industries? (Board’s Model Activity Sheet)
Answer:
Yeast i.e. Saccharomyces cerevisiae is used in the baking industries.

Question 2.
There is an oil layer on the water surface of river in your area. What will you do? (March 2019)
Answer:
If there is an oil layer on the water surface, we shall use hydrocarbonoclastic bacteria like Pseudomonas to clean up the oil spill.

Question 3.
(a) How are microbes used in sewage management?
(b) How is the sludge produced in this process utilized? (Board’s Model Activity Sheet)
Answer:
(a)

In cities, the sewage is sent to processing plant and is treated with microbes.
Microbes that carry out decomposition, are mixed with sewage. Such microbes are able to destroy, pathogens as well as decompose any compounds.
Some microbes bring about bioremediation of environment, that are used for treating sewage pollution.
Upon decomposition of the carbon compounds present in sewage, microbes release methane and CO₂.

(b) The sludge formed in this process, is used as fertilizer.

Question 4.
Answer the following questions:
(a) What is clean technology?
Answer:
Clean technology is the method to use microbes for controlling air, soil and water pollution. These microbes can degrade the manmade chemicals.

(b) Why is it essential to ban plastic bags?
Answer:
Plastic is a non-biodegradable substance. It cannot be degraded back into its original constituents. It remains just like that for many hundreds of years. It causes solid waste pollution in any environment wherever it is thrown indiscriminately. If burnt, it releases very toxic gases. If dumped in landfills it obstructs the other decomposition processes.

Write short notes on the following:

Question 1.
Production of Yoghurt.
Answer:

Yoghurt is one of the milk product produced from milk with the help of lactobacilli (inoculant).
In the industrial production of yoghurt, the milk is added with condensed milk powder. This increases the protein content of the milk. Then this milk is subjected to fermentation.
Milk is boiled and then it is cooled till it becomes lukewarm.
Then the bacterial strains of Streptococcus thermophiles and Lactobacillus delbrueckii are added to this lukewarm milk in 1:1 proportion.
The Streptococcus bacteria convert the milk into solution containing lactic acid. This makes the proteins to gel out. It makes the yoghurt dense.
The lactobacilli help in the formation of acetaldehyde like compounds giving a characteristic taste to the yoghurt.
For commercial reasons, various fruit juices are mixed with yoghurt to impart different flavours forming strawberry yoghurt, banana yoghurt, etc.
The pasteurization is carried out to increase the shelf life of yoghurt and improve its probiotic properties.

Question 2.
Production of cheese.
Answer:
Cheese is made from cow’s milk throughout the world. The steps in the process of cheese manufacture are as follows:

Chemical and microbiological testing of milk is done.
Three types of bacteria, viz. Lactobacillus lactis, Lactobacillus cremoris and Streptococcus thermophilus along with some colour is added to the milk.
It imparts sourness to the milk and it is converted into yoghurt like substance.
The water from this yoghurt, i.e. whey is not removed to make the yoghurt denser.
Enzyme, rennet or protease is added to the mixture to make it more denser.
Later cutting the solid yoghurt into pieces, washing, rubbing, salting, land mixing of essential microbes, pigments and flavours is done in suitable steps.
The pressed cheese is then cut in to pieces and stored for ripening.

Question 3.
Land-filling sites.
Answer:

In the land-filling sites the degradable wastes are transferred. Usually such sites are in urban areas.
The land-filling sites are away from the residential areas for the hygienic reasons. Here large pits arb dug in open spaces.
These pits are lined with plastic sheets. Therefore, the leaching of toxic and harmful materials is avoided to reduce the chance of soil pollution due to leachates.
Compressed waste is put in the pit and is covered with layers of soil, saw dust, leafy waste.
Specific biochemical substances are added for speedy decomposition.
Bioreactors which are mixtures of bacteria are mixed at some places.
Soil microbes and other top layers decompose the waste.
Soil slurry is used to seal the pits completely.
After a certain period, best quality compost is formed. Such land filling sites can be reused after removal of compost.

Complete the paragraph by choosing the appropriate words given in the brackets:

Question 1.
(Nocardia, Geobacter, Ideonella sakaiensis, Pseudomonas, Alcanovorax borkumensis, hydrocarbonoclastic, Acidophillium, streptomyces)
Bacteria like ………… spp. and ………. have the ability to destroy the pyridines and other chemicals. Hence, these bacteria are used to clear the oil spills. These are called ………. bacteria. It has been observed that species like Vibrio, …………… can decompose the PET. Similarly, species of fungi like ………… have ability of decomposing rubber from garbage. Sulphuric acid is source of energy for some species of bacteria like ………… Hence, these bacteria can control the soil pollution occurring due to acid rain. …………..convert the salts of uranium into insoluble salts.
Answer:
Bacteria like Pseudomonas spp. and Alcanovorax borkumensis have the ability to destroy the pyridines and other chemicals. Hence, these bacteria are used to clear the oil spills. These are called hydrocarbonoclastic bacteria. It has been observed that species like Vibrio, Ideonella sakaiensis can decompose the PET. Similarly, species of fungi like Nocardia have ability of decomposing rubber from garbage. Sulphuric acid is source of energy for some species of bacteria like Acidophillium. Hence, these bacteria can control the soil pollution occurring due to acid rain. Geobacter convert the salts of uranium into insoluble salts.

Read the paragraph and answer the questions given below:

Remediation is the process of removing dangerous or poisonous substances from the environment, or limiting the effect that they have on it. When any biological organism is used for remediation, it is called bioremediation. When plant species are used for the purpose of remediation, it is called phytoremediation. When any microbes are used then it is named as microbial remediation. The methods of such remediation have helped to clean the environment from toxic effluents, especially sewage and crude oil. Dr. Anand Chakraborty, a scientist of Indian origin, has worked on Pseudomonas aeruginosa which have reduced the crude oil films into carbon dioxide and water.

Questions and Answers:

Question 1.
What is the meaning of remediation?
Answer:
Remediation is the process by which dangerous or toxic substances are removed from the environment.

Question 2.
What is the difference between phytoremediation and microbial remediation?
Answer:
When any plant species are used for remediation process, then it is called phytoremediation, whereas when any microbe species used for remediation then it is called microbial remediation.

Question 3.
Which environmental pollutant is mainly removed through bioremediation processes?
Answer:
Toxicants released through sewage and crude oil are removed by bioremediation processes.

Question 4.
What is the role of Pseudomonas aeruginosa?
Answer:
Pseudomonas aeruginosa helps in bioremediation by acting on film of crude oil and reduces it to carbon dioxide and water.

Question 5.
Why Dr. Anand Chakraborty’s work phenomenal?
Answer:
Dr. Anand Chakraborty discovered that Pseudomonas aeruginosa bacteria can act on oil film which is toxic and reduce it to nontoxic products. This helps in controlling the oil pollution of marine waters which otherwise is very difficult to control.

Diagram based questions:

Question 1.
Observe the diagram and answer the following questions:

(a) Name the following method of solid waste management.
Answer:
The above diagram shows modern landfill site. This method is used for solid waste management.

(b) What type of waste is used in this method?
Answer:
In this method only degradable waste matter collected in cities can be used. Such solid waste can undergo biodegradation and hence can be managed in an eco-friendly way.

(c) What kind of useful substances can be obtained from such methods?
Answer:
From such decomposition, organic fertilizers and manure formed through composting are obtained. Methane gas is also obtained which is used as fuel.

Question 2.
Observe the Figure 7.1 and answer the following questions: (March 2019)

(a) Identify the process shown in the figure.
Answer:
The figure shows modern land fill site where microbial biodegradation process is carried out.

(b) Explain the process in short.
Answer:
Land-filling sites:

In the land-filling sites the degradable wastes are transferred. Usually such sites are in urban areas.
The land-filling sites are away from the residential areas for the hygienic reasons. Here large pits arb dug in open spaces.
These pits are lined with plastic sheets. Therefore, the leaching of toxic and harmful materials is avoided to reduce the chance of soil pollution due to leachates.
Compressed waste is put in the pit and is covered with layers of soil, saw dust, leafy waste.
Specific biochemical substances are added for speedy decomposition.
Bioreactors which are mixtures of bacteria are mixed at some places.
Soil microbes and other top layers decompose the waste.
Soil slurry is used to seal the pits completely.
After a certain period, best quality compost is formed. Such land filling sites can be reused after removal of compost.

Activity based questions:

Question 1.
Collect Information Search : (Textbook page no. 84)
(i) Which materials should not be present in garbage for its proper microbial decomposition?
Answer:
If there are non-biodegradable materials in the garbage, they will not decompose. The plastic, glass, metals etc. will not undergo microbial decomposition, therefore, such items should not be- there in the garbage. The toxic matter, hazardous chemicals and e-waste should also be removed. If such materials are present in the garbage, the microbes will be killed and the entire process of decomposition will be suffered.

(ii) How the sewage generated in your house or apartment is disposed off ?
Answer:
The sewage generated in our house is carried by the drainage pipes to municipal sewage treatment plants. Here, primary, secondary and tertiary treatment is done on the sewage. The safe water is then released into the ocean.

Question 2.
Observe: (Textbook page no. 83)
Observe the garbage vans of gram panchayat and municipality. Nowadays, there is facility of decreasing the volume of garbage by compaction in those vans. Explain the advantages of this activity.
Answer:
When the garbage is compressed, its volume is reduced. The trips of the vans that pick up the garbage can be reduced due to such measures. The land filling sites can also accommodate more garbage if it is compacted.

Question 3.
Observe the figure and answer the following:

(i) Lack of management of which factor is shown in the picture?
Answer:
The above picture shows the lack of management of sewage resulting in waste water being dumped carelessly.

(ii) How can that factor be managed with the help of microbes?
Answer:
Microbes which can destroy the pathogens of cholera, typhoid, etc. are mixed with sewage. They release methane and CO₂ by decomposition of the carbon compounds present in sewage. Other microbes that decompose chemical compounds are also released. Phenol oxidizing bacteria decompose the xenobiotic chemicals present in sewage.

(iii) How are the oil spills in oceans cleared?
Answer:
Hydrocarbonoclastic bacteria like
Alcanivorax borkumensis and Pseudomonas are used to clear the oil spillage from ocean water. These bacteria decompose the hydrocarbons. They bring about the reaction of released carbon with oxygen to produced CO₂ and water.

Projects: (Do it your self)

Project 1.
Search: (Textbook page no. 81)
Read the ingredients and their proportion printed on bottles of cold drinks and juices and wrappers of ice creams. Find out the natural and artificial ingredients.

Project 2.
Internet is My Friend: (Textbook page no. 85)
Collect pictures of various useful microbes. Display chart of their information in the classroom.

Project 3.
Observe the figure given on Textbook page no. 82. Discuss about bio-fuel?

10th Std Science Part 2 Questions And Answers:

Social Health Class 10 Questions And Answers Maharashtra Board

January 6, 2025January 5, 2025 by Bhagya

Balbharti Maharashtra State Board Class 10 Science Solutions Part 2 Chapter 9 Social Health Notes, Textbook Exercise Important Questions and Answers.

Std 10 Science Part 2 Chapter 9 Social Health Question Answer Maharashtra Board

Class 10 Science Part 2 Chapter 9 Social Health Question Answer Maharashtra Board

Question 1.
Fill in the blanks with appropriate word.
a. Laughter club is a remedy to drive away …………..
(a) stress
(b) addictions
(c) lethargy
(d) epidemics
Answer:
(a) stress

b. Alcohol consumption mainly affects …………. system.
(a) digestive
(b) respiratory
(c) nervous
(d) excretory
Answer:
(c) nervous

c. IT Act 2000 is to control the ……….
(a) housebreaking
(b) cybercrimes
(c) cheating
(d) pickpocketing
Answer:
(b) cybercrimes

Question 2.
Answer the following.
a. Which factors affect the social health?
Answer:
(1) In order to maintain the social health of any community there should be good amenities for the people. E.g. food, water, shelter, clothing, medicines and medical help, equal opportunities for education, cleanliness of the surroundings, transport facilities etc. should be properly provided.

(2) The social and political conditions of the surrounding should be such that there should not be any connections with world of criminals. The presence of such criminal ties can affect the social health to a great extent.

(3) The gardens, playgrounds, the empty plots for outdoor games, sports clubs, etc. are important criteria for overall development of the society. This results into personality development and make people happy and strong.

(4) Addictions, criminal tendencies, pervert behaviour and perverse thinking affects other people in the society and this reflects negatively on the social health.

(5) Having large number of friends and relatives, proper use of time when alone and when along the peer group, trust in others, respect and acceptance for others build stronger social health.

b. Which changes occur in persons continuously using the internet and mobile phones?
Answer:

When a person continuously remains in contact with mobile phones, many physical problems can arise.
Tiredness, headache, insomnia, forgetfulness, tinnitus, joint pains and problems in vision occur due to radiation emanating from the cell phones. For young children this is more disastrous as these radiations can penetrate through their bones.
By logging into the internet for a long time, persons become solitary. Such individuals are unable to establish harmonious relations with relatives and other people around.
They tend to become self-centred and selfish, They lose sensitivity towards others.
Such people never take any social responsibility and the social health is thus disturbed.

c. Which problems does the common man face due to incidences of cybercrime?
Answer:

The numbers of Aadhaar card, PAN card, credit or debit card are obtained by the cheaters. This is a cybercrime. The PIN number can be misused and the money can be withdrawn from the bank accounts. The looters withdraw cash from our accounts in this way.
People can be cheated during online shopping.
Fake account on Facebook is opened and false information is displayed on it. Through such accounts the girls are emotionally and financially exploited.
Electronic media are misused for sending derogatory and vulgar messages, obscene pictxfres and provocative statements.
Through the internet, hackers can send virus to crash someone’s computer or even mobile phones.
In all such different ways, common people can be victimized by cybercrime.

d. Explain the importance of good communication with others.
Answer:

Nowadays, there is fierce competition, insecurity and criminal tendencies in the society.
This kind of atmosphere is increasing mental and emotional stress.
If the stress remains buried in the mind, persons are depressed or frustrated. This causes, mental disorders if not treated in time. Depression can lead to addictions. The suicidal thoughts hover in the mind. If at that phase we can open our heart by good communication, many problems can be solved.
Help from counsellors can be taken to relieve the stress.
By good communication with parents or family members harmonious relations can be re-established.

Question 3.
Solve the following crossword.

1. Continuous consumption of alcoholic and tobacco materials.
Answer:
Addiction

2. This app may cause the cybercrimes
Answer:
Facebook

3. A remedy to resolve stress.
Answer:
Singing

4. Requirement for stress free life.
Answer:
Goodfood

5. Various factors affect ……….. health.
Answer:
Social

6. Art of preparing food items.
Answer:
Cooking.

Question 4.
What are the various ways to minimize mental stress?
Answer:
The ways of stress-bursting are as follows:
(1) Laughter club: People gather together and laugh collectively to reduce stress.

(2) Good communication: One should establish good communication with friends, siblings, cousins, teachers, parents or anybody in whom we can confide and express our feelings.

(3) Writing: By writing and noting the thoughts we feel relieved. We can confess and analyse about our mistakes through writing to reduce our stress.

(4) Hobbies: Collecting curios, photography, reading good literature, music, cooking, gardening, bird watching, keeping a pet, sculpturing, drawing, rangoli, dancing, etc. are such hobbies which are necessary for utilizing our spare time by creativity. Persuading hobby is the best way to be stress-free. Music in particular is said to change the negative thoughts, therefore, listening to music, learning the music and singing helps to fight stress. By admiring nature too, stress is relieved.

(5) Outdoor games and physical exercise: By participating in the sports, there are various benefits such as physical exercise, improving discipline, interaction with others and creating the tendency of unity, becoming more social and reduce stress.

Question 5.
Give three examples of each.
a. Hobbies to reduce stress.
Answer:

To listen to music
Bird watching and nature trails
Reading good books.

b. Diseases endangering the social health.
Answer:

AIDS
Tuberculosis
Leprosy.

c. Physical problems arising due to excessive use of mobile phones.
Answer:

Headache
Vision problems
Joint pains.

d. Activities under the jurisdiction of cybercrime laws.
Answer:

To do bank transactions by procuring PIN number of somebody.
Misuse of written material of someone or illegal sale of the same.
Hacking the information of government institutes and companies.

Question 6.
What will you do? Why?
a. You are spending more time in internet/mobile games, phone, etc.
Answer:
In life, the time once spent never returns back. We therefore must use our time for studies, exercise or outdoor games and some entertainment. In the free time, we must also help our parents in house hold work. But if we are spending hours together on surfing the net without any perfect aim or playing the computer or cell phone games it is total waste of time.

There are many inappropriate sites on the internet, which should not be watched. This causes stress. Continuous use of mobile phone and being hooked to the social media slowly becomes an addiction. If these bad habits are creeping in us, we must try to leave the habits by conscious change.

b. Child of your neighbour is addicted to tobacco chewing. (July 2019)
Answer:
The hazards of tobacco chewing will be explained to this child. Different photographs and videos showing the conditions of oral cancer will be shown to this child to persuade him, so that he can stay away from tobacco. This addiction has to be removed, so help of his parents will be taken. They will be told about the child’s habit and asked to help ? him free from his addiction.

c. Your sister has become incommunicative. She prefers to remain alone. (July 2019)
Answer:
The individual who prefers to be incommunicative has lots of thoughts in his/her mind. If this is the case with sister, she will be taken into confidence and the reason behind this lack of communication will be found out. Most often such persons have depression. So she will not be left alone. Her friends will be invited at home, so that she can converse with them. She should be motivated to mix with her favourite people. She should be encouraged to pursue her hobbies. She should be helped in selecting such work, If nothing changes her, then the help of counsellor should be taken.

d. You have to use free space around your home for good purpose.
Answer:
The free space around our home can be used to make a small garden. The garden-soil can be bought and spread in this free space. Small saplings can be planted here and nurtured for further growth. Nursery of saplings can also be started in this free space.

The space can also be used for outdoor games. The net for Badminton can be fixed and evening times can be spent in playing the game. Also care will be taken to keep the space clean and without any garbage.

e. Your Mend has developed the hobby of snapping selfies. (July 2019)
Answer:
The habit of continuously taking selfie is bad. It shows that the friend is constantly thinking of himself only. His self-centredness is to be removed by counselling him. The reason behind this behaviour should also be understood. He should be diverted and motivated to take some other tasks so that his habit can be lessened. Taking selfies is not a hobby. It is a bad habit if someone is repeatedly engaged in it.

f. Your brother studying in XII has developed the stress.
Answer:
The syllabus for class XII is vast. If the studies are not taken seriously from the beginning of the academic year, then the stress develops due to the fear of examination and result. Therefore, instead of being stressed, he should practise time management and study schedule. He should think of only one subject at a time. The atmosphere in the house should be maintained happy and tension-free. Everybody in the house should interact with him so that he gets a feeling that he is not alone. He should be convinced, “study is for you and you are not for study”.

Question 7.
What type of changes occur in a home having chronically ill old person? How will you help to maintain good atmosphere?
Answer:
If there is a chronically ill old person in the house, the entire atmosphere of the house changes. There is tension and grief in the house. Doctor’s visits to the house become routine. The ill person’s diet and medicines are strictly followed.

In such times, everybody in the family should contribute to the work of taking care of the patient. We can help in bringing medicines. We can sit beside the patient during night time. We should maintain pleasant atmosphere in the house. We should help the person who is burdened by the duties towards the sick patient by helping in whatever little ways that we can.

Project: (Do it your self)

Project 1.
Enlist various factors affecting the social health in your residential area. Decide the necessary changes to correct the situation and implement those changes.

Let’s Think: (Text Book Page No. 101)

Question 1.
Elders always instruct you to get out of the home to interact with relatives and others and play outdoor games but not to spend time continuously with television, phone and internet. Why the children of your age are instructed same in each home?
Answer:
When we interact with the relative, it becomes easier to mix with other strangers later. The personality moulds when we talk and interact with different people. We can exchange the thoughts. We learn to converse in a rightful way. When we go to playground and take part in outdoor games, we get health benefits. Sitting at home and spending productive time in just mobile or computer games, does not benefit in any way.

Most of the serials on the television are of no use for any kind of personality development, instead they push us in a virtual world. Except for few channels like National Geographic and Animal Kingdom, we do not get any knowledge by television viewing.

The elders in the house are experienced people. They understand ‘what is good’ and ‘what is to be avoided’. They are also genuinely concerned about bright future of the youngsters in the house. By giving instructions to the youngsters, they never get benefitted but it is our generation that gets proper guidance. These instructions should be followed for a perfect personality and bright future.

Think: (Text Book Page No. 103)

Question 1.
Whether the incidence shown in the following picture is rational? Express your opinion.

Answer:
In the picture is seen a woman asking the beggar to move away. The beggar looks dirty and sick. In one way, the picture looks proper as the beggar may be causing inconvenience to the people in that house. He is unhygienic and may spread the- infection. But from the humanitarian point of view, he may be needing help. He may be starving. He may be sick. In such a case, Jie should be given food and help.

However, if he is a drug addict the police should be called and person should be transferred immediately. From the picture, the exact condition of the man is not clearly understood and hence, the exact opinion about the rationality of the incidence cannot be made.

Observe: (Text Book Page No. 103)

Question 1.
Two caricatures presenting the situations of the year 1998 and 2017 about playing on playground are given below. Observe those caricatures. Express your opinion about arising of such different situations.

Answer:
In 1998, the technology was not so much advanced as it is today. In every house, there were no computers or laptops. Mobile phones were not popular then. The children used to play games which were outdoor and physical. They used to spend quality time on the playground. They always wanted to rush to the playground after their school hours. Therefore, mothers of that time had the task to get back their children from the playground.

By 2017, the situations and the social and technological change became enormous. The constant growth of the cities also experienced the rising construction. This too resulted in loss of playgrounds. After school time, children started spending their time in mobile and computer games. The parents also became financially well-off and started providing all the amenities to the children.

Due to the internet and the computer at home, the children got hooked to these electronic media. They started spending all the available time in virtual games, Facebook, what’s app and other social media. Thus mothers, of recent times had to force their children out of the house, at least for some time, so that they can play physical games.

Two caricatures presenting the situations of the year 1998 and 2017 about playing on playground show the tremendous social change that has undergone in our society.

Observe: (Text Book Page No. 104)

Question 1.
Observe the images below. Is it rational? Why?

Answer:
In the above three pictures three incidences are shown. In the first picture (Fig. 9.3), the boy who is taking his lunch is shown. He is busy with his mobile while having his food. In second picture (Fig. 9.4), a young man is taking selfie while standing in the busy road. He is not aware of the approaching car too. In the third picture (Fig. 9.5), some men are taking pictures of the accident that has recently happened. The person is injured and bleeding. But these men-are busy in photographing him.

All the three pictures are showing irrational and improper behaviour. We should respect the food while eating. We should eat in a disciplined way. Standing in the middle of the road and taking selfie is like inviting the mishap. Selfie taken in such circumstances usually results in an accident. In the last picture, the sensitivity and the humanity to save the victim is lacking. If the victim is immediately rushed to hospital, his life can be saved. Instead of helping the victim if people are engrossed in taking pictures, then it is absolutely wrong.

Choose the correct alternative and write its alphabet against the sub-question number:

Question 1.
Our ……… has been changed to some extent in the age of technology.
(a) lifestyle
(b) habit
(c) circumstance
(d) passion
Answer:
(a) lifestyle

Question 2.
………… influence is stronger in case of adolescents.
(a) Teacher’s
(b) Father’s
(c) Relative’s
(d) Peer group
Answer:
(d) Peer group

Question 3.
Tobacco containing substances has ……….. effect on mouth and lungs.
(a) acidic
(b) alkaline
(c) carcinogenic
(d) neutral
Answer:
(c) carcinogenic

Question 4.
Persons continuously using computers and the internet become …………..
(a) courageous
(b) timid
(c) solitary
(d) criminal
Answer:
(c) solitary

Question 5.
…………. has been newly launched in Police Department.
(a) Cybercrime unit
(b) Women protection unit
(c) Senior citizen care unit
(d) Forensic unit
Answer:
(a) Cybercrime unit

Question 6.
…………. helps to improve concentration in the studies.
(a) Eatables
(b) Meditation
(c) Hobbies
(d) Sports
Answer:
(b) Meditation

Question 7.
Hobbies like rearing pet animal helps to create a …………..
(a) positive mindset
(b) negative attitude
(c) wealth
(d) concentration
Answer:
(a) positive mindset

Find the odd one out:

Question 1.
Transport facilities, Social security, Counselling, Toilets.
Answer:
Counselling. (All others are factors affecting social health. Counselling is the positive measure for mental health.)

Question 2.
Aadhaar card, PAN card, Greeting card, Credit card.
Answer:
Greeting card. (All others are important cards of personal use.)

Question 3.
What’s app, Instagram, Facebook, Textbook.
Answer:
Textbook. (All others are social media.)

Question 4.
Tobacco, Laughter club, Alcoholism, Drug abuse.
Answer:
Laughter club. (All others are addictions.)

Find out the correlation:

Question 1.
Movement against tobacco : Tata trust : : Education of slum children : …………..
Answer:
Movement against tobacco : Tata trust : : Education of slum children : Salaam Mumbai Foundation

Question 2.
Addictive substances : Drugs : : Carcinogenic (Cancer causing) substances : ………..
Answer:
Addictive substances : Drugs : : Carcinogenic (Cancer causing) substances : Tobacco

Question 3.
Radiations from cell phones : Headache : : ………….. : Hindrance to the brain development.
Answer:
Radiations from cell phones : Headache : : Alcoholism : Hindrance to the brain development.

Select the two options in the ‘B’ group related to ‘A’ group:

Question 1.

‘A’ Group	‘B’ Group
(1) Salaam Mumbai Foundation	(a) Work against alcoholism
	(b) Freedom from tobacco
	(c) Laughter club
	(d) Help to improve student’s lifestyle

Answer:
(1) Salaam Mumbai Foundation – (b) Freedom from tobacco (d) Help to improve student’s lifestyle.

Give scientific reasons:

Question 1.
Nowadays school going children suffer from mental stress.
Answer:

These days children stay in nuclear families. Due to need for earning and also due to her career choices, mother of the house is also away for long period of time.
The grandparents or other elders are not in the home. This makes the children alone in the house.
At school and during studies, there is fierce competition. The modern technology like internet or mobile phones are luring the children away from their regular exercises or outdoor games.
The wrong kind of peer pressure introduces addictive substances at the young age.
There is insecurity in the outside world for the young children.

These facts create emotional burden on the young minds and thus they suffer from mental stress.

Question 2.
Girls are facing the problem of stress due to such gender inequality.
Answer:

In most of the households there are many bindings on girls and excessive freedom for boys.
Boys do not participate in the domestic duties whereas girls have compulsion for the same.
In society too, girls have to face the problems like teasing and molestation.
This creates insecurity among the minds of girls.
The social change has made women independent and equal but still the male dominated society and the gender inequality persists causing more stress for young girls.

Question 3.
Consuming liquor is always bad.
Answer:

When the liquor is produced from alcohol wrong processes can be carried out which makes the liquor highly toxic.
It may cost the life too. Due to alcohol in the liquor, there is directly effect on the nervous system and especially on the brain.
Other vital organs such as liver and kidneys are harmed due to alcohol.
The lifespan of person decreases due to alcoholism.
In students, the brain functioning is affected and the ability to memorize and think rationally is lost. The learning process becomes slow.
Due to all these effects, there is social, mental and familial problems in the society. Therefore, consuming liquor is always bad.

Question 4.
We need to keep the PIN number of the debit card secret.
Answer:

Debit card is used to withdraw our money from the bank account.
During withdrawal, we have to use our PIN number.
If this PIN number is known to anybody, he or she can withdraw all our money and loot us.
Therefore, to prevent such financial loss, we have to keep the PIN number of the debit card secret.

Question 5.
Importance of outdoor games is unparalleled.
Answer:

Outdoor games give good physical exercise. These games give many physical benefits.
It improves personal discipline, interaction with fellow players and created sense of unity.
Through play by driving away the loneliness, mental stress and depression is reduced.
The person becomes more social.
Therefore, it is said that the importance of outdoor games is unparalleled.

Answer the following questions:

Question 1.
What is alcoholism? What are its effects?
Answer:

Alcoholism is the addiction to have alcohol in the form of different types of liquor. Liquor is produced from alcohol. Alcohol is in turn obtained by fermentation of different substances.
Consuming liquor becomes an addiction for a long-term. Due to alcohol, the efficiency of nervous system and especially the brain is affected.
Other vital organs such as kidneys and liver are adversely affected.
Lifespan of an alcoholic decreases due to constant drinking and malnourishment.
Especially in adolescent age if alcohol is consumed the brain functioning does not take place properly. The mental ability of memorization and learning becomes slow. There is lack of concentration in studies.
The alcoholic person lacks the rational thinking and hence faces with social, mental and familial problems along with physical illness.

Question 2.
How the excessive use of social media and technology is proving harmful?
Answer:
Excessive use of social media and modem technology is disturbing the social health. It is also affecting physical and mental health. Increase in cybercrime take place. People waste their time by watching useless and obscene material. Violence develops by watching few weird cartoon serials. Dependency on machine rises and persons lose self-reliance.

Question 3.
Explain the importance of exercise, yoga and meditation.
Answer:

Exercise, yoga and meditation are the ways to reduce mental and physical stress.
In yoga various asanas and pranayama are performed. It also includes good food and discipline of the body and mind.
Deep breathing, yogic sleep can help in the building up health.
Meditation helps in concentration and brings positivity to the mind. Especially, the students increase the concentration in the studies.

Write short notes on the following:

Question 1.
Cybercrimes.
Answer:

No personal information should be shared on the phone, especially the details of bank account, Aadhaar card, PAN card, credit card or debit card number, etc. Cheating persons by using this information is a greatest cybercrime.
If PIN of any debit or credit card is known to a stranger, he or she can make fraudulent transactions.
The PIN number and CVV number should be kept total secret. Otherwise, the bank transactions, are done using PIN without the knowledge of consumers.
In on-line purchases, many a times consumers are cheated. In this, the consumers are shown superior items on websites but actually the inferior ones are sold to them.
‘Hacking of information’ is done by some programmers in which the confidential information about government, institutes and companies is obtained from internet with the help of computer programs.
Fake Facebook accounts are opened and false information is displayed there. This is for harassing girls or financially exploiting others.
In internet piracy, written literature, software, photos, videos, music, etc. of other persons are misused or illegally used.

Misuse of electronic media sending derogatory messages, spreading vulgar pictures and provocative statements is also a cybercrime. Very rapid exchange of information through media like email, Facebook and Whatsapp takes place these days. But we have to take care about leaking of our own important information.

However, when our personal information and phone numbers are automatically spread and reached to fraudulent people, then they commit malpractices which can hinder the function or shut of the cell phones or computers. All these are cybercrimes which are also indicative of mental health.

Question 2.
Addiction.
Answer:
(1) In adolescent age group, there is tremendous pressure of peers. This peer-group influence can be at times wrong, if the friends are not good. Instead of following advice of parents, the adolescent girls and boys tend to listen to the wrong advices of their friends.
(2) Due to lack of parental supervision, children in their early age start using tobacco, cigarette, gutkha, alcoholic drinks, drugs, etc. This may be due to peer-pressure.
(3) The children fall into the trap of addictions either due to peer-group pressure or due to false
symbol of high standard living. Sometimes they try to imitate their elders.
(4) The addictive substances are hazardous, and they cause long term effects. Some are temporarily intoxicating substances obtained from the plants. While some of the chemical ingredients in them can permanently damage the human nervous system, muscular system, heart, etc. Some tobacco like substances Eire carcinogenic in action especially on the mouth and lungs.

Complete the paragraph by choosing the appropriate words given in the bracket:

Question 1.
(lungs, heart, carcinogenic, nervous, intoxicating, hazardous, addictions, peer-group)
The children fall into the trap of …………. either due to ……….. pressure or due to false symbol of high standard living. Sometimes they try to imitate their elders. The addictive substances are ………….., and they cause long term effects. Some are temporarily ………… substances obtained from the plants. While some of the chemical ingredients in them can permanently damage the human ……… system, muscular system, …………, etc. Some tobacco like substances are ………. in action especially on the mouth and ………….
Answer:
The children fall into the trap of addictions either due to peer-group pressure or due to false symbol of high standard living. Sometimes they try to imitate their elders. The addictive substances are hazardous, and they cause long term effects. Some are temporarily intoxicating substances obtained from the plants. While some of the chemical ingredients in them can permanently damage the human nervous system, muscular system, heart, etc. Some tobacco like substances are Carcinogenic in action especiailly on the mouth and lungs.

Paragraph based questions:

1. Read the paragraph and answer the questions given below:
Social health involves your ability to form satisfying interpersonal relationships with others.
It also relates to your ability to adapt comfortably to different social situations and act appropriately in a variety of settings. Spouses, co-workers and acquaintances can all have healthy relationships with one another. Each of these relationships should include strong communication skills, empathy for others and a sense of accountability. In contrast, traits like being withdrawn, vindictive or selfish can have a negative impact on your social health. Overall, stress can be one of the most significant threats to a healthy relationship. Stress should be managed through proven techniques such as regular physical activity, deep breathing and positive self-talk.

Questions and Answers:

Question 1.
How can you be socially healthy?
Answer:
If one has ability to form satisfying interpersonal relationships with others, he or she can be socially healthy. In all social situations and settings there should be appropriate behaviour.

Question 2.
Which qualities are needed for having good social contacts?
Answer:
Strong communication skills, empathy for others and sense of accountability are the qualities needed for having good social contacts.

Question 3.
Which traits have negative impacts on social health?
Answer:
Being withdrawn, vindictive or selfish, and stressed out personality has negative impacts on the social health.

Question 4.
What are the stress management techniques?
Answer:
Regular physical activity, deep breathing and positive self-talk can be the simple stress management techniques.

Question 5.
What is the significant threat to social health of an adolescent in your opinion?
Answer:
General stress, addictions, wrong peer pressure, too much screen time, lack of parental care are threats to social health of an adolescent.

Activity based questions:

Question 1.
Fill in the boxes with the help of the given clue: (March ’19)
Continuous consumption of alcohol and tobacco material …………

Answer:
ADDICTION

Question 2.
Observe the pictures and answer the questions. (March’19)
(a) Playing games on mobile while eating is right or wrong. Justify.

Answer:
The boy taking his lunch is shown in the adjoining picture. He is busy with his mobile while having his food. His nutrition may affect due to such behavior.

(b) What do you conclude from the following picture?

Answer:
Cigarette contains carcinogenic nicotine. It should never be smoked. Similarly, always stay away from addictions such as drugs, alcohol, gutkha, etc. The pictures give message for control of addictions.

(c) Observe the following picture and state what can be the outcome?

Answer:
In picture, a young man is taking selfie while standing in the busy road. He is not aware of the approaching car too. This may cause an accident.

Question 3.
Complete the following:
Concept-diagram using factors harming the social health and based on it, answer the following questions :
(i) Tobacco products can be included in which of those factors?
(ii) How the tobacco products are harming the social health?
Answer:
(Answers are given in bold.)

(i) Tobacco products are included under addiction.
(ii) Tobacco is carcinogenic product. By its consumption personal and social health is affected on a large scale. Spitting tobacco anywhere is also common practice among tobacco chewers. This too affects public hygiene and cleanliness.

Question 4.
(9) Observe the following figure and answer the given questions: (Board’s Model Activity Sheet)

(a) What does this picture given in the textbook indicate?
(b) Explain any two causes for this problem.
(c) Describe any two measures to eradicate this problem.
Answer:
(a) Given picture indicates that person is suffering from mental problem. He is under sever depression and frustration. Person may be using the drugs.

(b) Causes of this problems are as under:

Nuclear families and working parents.
Poverty, divided family and unemployment. Addiction is major cause of this problem.

By good communication with parents or family members harmonious relation can be re-established.
Help from counsellors can be helpful to minimize the problem.

Question 5.
(i) Which mental illness is shown in the picture 9.5?

(ii) Which social message would you like to give through it.
Answer:
(i) The picture (figure 9.5) shows ‘insensitivity’, which is a type of human nature.
(ii)

Instead of shooting the accident the victim should be given first aid.
Call on 100 and 108 and seek immediate help from police and ambulance.
Disperse the crowd and try to save life of victim by giving CPR.

Question 6.
Write, which is an inappropriate action in the picture 9.5? (Board’s Model Activity Sheet)
Answer:
The picture shows lack of sensitivity and responsibility.

Question 7.
Observe the figure and answer the questions given below.

(a) What do these figures indicate?
(b) Which gadgets can be misused for these?
(c) Give two examples of such events.
(d) Name the act amended by Government of Maharashtra to control such events.
(e) What care should be taken by a person to avoid such events?
Answer:
(a) The above figures indicate different types of cybercrime.

(b) The gadgets that are usually used for cybercrime are internet connected computers, cell phones, ATM machines, debit and credit cards, etc. Also using aadhar and PAN cards of others.

(c) (1) Bank transactions are done without the knowledge of the account holder by stealing necessary numbers or pass codes. (2) By opening the fake accounts of social media and deceiving girls, harming them psychologically by teasing them. (3) Deceiving customers by showing superior options on the internet and providing inferior ones when bought. In online shopping many may be cheated in this way.

(d) IT Act-2000 is the act enacted since 17th Oct. 2000 and amended in 2008 that has been imposed by Government of Maharashtra to control cybercrimes.

(e) To prevent cybercrimes, one has to keep vigil over bank transactions. Never reveal any details on the phone. The ATM pin number and PAN or AADHAR details should not be revealed to anyone. While at ATM machines, the pin number should be covered. Always log out from the internet after the work is over.

Projects:

Project 1.
Observe and Discuss: Observe the chart given on textbook page 101. Discuss about the relationship of various factors shown therein with the social health. (Textbook page no. 101)

Project 2.
Try This! (Textbook page no. 101) Classify your classmates into following groups depending upon the observation for a week.
1. Highly interactive.
2. Occasionally interactive.
3. Non-interactive
Make a list of the friends of each of the above three group members and also mention the group to which you belong.

Project 3.
Compare: (Textbook page no. 103) Distribute the 24 hours of your daily routine as per various duties you have observed. Make two categories as time spent on your health and time spent on other responsibilities and compare both the categories.

Project 4.
Internet is my friend: Visit the website www.cyberswachhtakendra.gov.in

10th Std Science Part 2 Questions And Answers:

Gravitation Class 10 Questions And Answers Maharashtra Board

January 6, 2025January 5, 2025 by Bhagya

Balbharti Maharashtra State Board Class 10 Science Solutions Part 1 Chapter 1 Gravitation Notes, Textbook Exercise Important Questions and Answers.

Std 10 Science Part 1 Chapter 1 Gravitation Question Answer Maharashtra Board

Class 10 Science Part 1 Chapter 1 Gravitation Question Answer Maharashtra Board

Class 10 Science Chapter 1 Gravitation Exercise Question 1.
Study the entries in the following table and rewrite them putting the connected items in a single row :

I	II	III
Mass	m/s²	Zero at the centre of the earth
Weight	kg	Measure of inertia
Acceleration due to gravity	N.m²/kg²	Same in the entire universe
Gravitational constant	N	Depends on height

Answer:

I	II	III
Mass	kg	Measure of inertia
Weight	N	Depends on height
Acceleration due to gravity	m/s²	Zero at the centre of the earth
Gravitational constant	N.m²/kg²	Same in the entire universe

Gravitation Class 10 Maharashtra Board Question 2.
Answer the following questions.
(a) What is the difference between mass and weight of an object? Will the mass and weight of an object on the earth be the same as their values on Mars? Why?
Answer:
The mass of an object is the amount of matter present in it. It is same everywhere in the Universe and is never zero. It is a scalar quantity and its SI unit is kg. The weight of an object is the force with which the earth (or any other planet/ moon/star) attracts it. It is directed towards the centre of the earth. The weight of an object is different at different places on the earth. It is zero at the earth’s centre. It is a vector quantity and its SI unit is the newton (N). The magnitude of weight = mg.

The mass of an object will be the same on the earth and Mars, but the weight will not be the same because the value of g on Mars is different from that on the earth.

(b) what are (i) free fall, (ii) acceleration due to gravity (iii) escape velocity (iv) centripetal force?
Answer:
(i) Free fall:
Whenever an object moves under the influence of the force of gravity alone, it is said to be falling freely.

(ii) Acceleration due to gravity:
The acceleration produced in a body due to the gravitational force of the earth is called the acceleration due to gravity.
[Note: On the earth’s surface, the value of the acceleration due to gravity is almost uniform. If a body falls from a low altitude, the value of the acceleration due to gravity is almost the same.]

(iii) Escape velocity:
When a body is thrown vertically upward from the surface of the earth, the minimum initial velocity of the body for which the body is able to overcome the downward pull by the earth and can escape the earth forever is called the escape velocity.

(iv) Centripetal force:
In uniform circular motion of a body, the force acting on the body is directed towards the centre of the circle. This force is called centripetal force.

(c) Write the three laws given by Kepler. How did they help Newton to arrive at the inverse square law of gravity?
Kepler’s first law :
The orbit of a planet is an ellipse with the Sun at one of the foci.

Figure 1.5 shows the elliptical orbit of a planet revolving around the Sun (S).

Kepler’s second law :
The line joining the planet and the Sun sweeps equal areas in equal intervals of time.
A → B, C → D and E → F are the displacements of the planet in equal intervals of time.
The straight lines AS, CS and ES sweep equal areas in equal intervals of time.
Area ASB = area CSD = area ESF.

Kepler’s third law :
The square of the period of revolution of a planet around the Sun is directly proportional to the cube of the mean distance of the planet from the Sun.
Thus, if r is the average distance of the planet from the Sun and T is its period of revolution, then,
T² ∝ r², i.e., \(\frac{T^{2}}{r^{3}}\) = constant = K

For simplicity, we shall assume the orbit to be a circle.

In Fig. 1.6,
S denotes the position of the Sun, P denotes the position of a planet at a given instant and r denotes the radius of the orbit (= the distance of the planet from the Sun). Here, the speed of the planet is uniform.

If m is the mass of the planet, the centripetal force exerted on the planet by the Sun (= gravitational force),

According to Kepler’s third law,

Thus, F ∝ \(\frac{1}{r^{2}}\) as \(\frac{4 \pi^{2} m}{K}\) is constant in a particular case.

(d) A stone thrown vertically upwards with initial velocity u reaches a height ‘h’ before coming down. Show that the time taken to go up is same as the time taken to come down.
Answer:

We have, v = u + at …..(1)
and s = ut + \(\frac{1}{2}\) at² …..(2)
∴ s = (v – at) t + \(\frac{1}{2}\) at²
= vt – at² + \(\frac{1}{2}\) at²
∴ s = vt – \(\frac{1}{2}\) at² …..(3)
As the stone moves upward from A → B,
s = AB = h, t = t₁,
a = -g (retardation),
u = u and v = 0
∴ From Eq. (3), h = 0 – \(\frac{1}{2}\) (-g)t₁²
∴ h = \(\frac{1}{2}\)gt₁² …..(4)
As the stone moves downward from B → A,
t = t₂, u = 0, s = h and a = g
∴ from Eq. (2), h = \(\frac{1}{2}\) gt² …..(5)
From Eqs. (4) and (5), t₁² = t₂²
∴ t₁ = t₂ (∵ t₁ and t₂ are positive)

(e) If the value of g suddenly becomes twice its value, it will become two times more difficult to pull a heavy object along the floor. Why?
Answer:
To pull an object along the floor, it is necessary to do work against the force of friction between the object and the surface of the floor. This force of friction is proportional to the weight, mg, of the object. If the value of g becomes twice its value, the weight of the object and hence the force of friction will become double. Therefore, it will become two times more difficult to pull a heavy object along the floor.

10th Gravitation Chapter Exercise Question 3.
Explain why the value of g is zero at the centre of the earth.
The value of g changes while going deep inside the earth. It goes on decreasing as we go from the earth’s surface towards the earth’s centre.

We shall treat the earth as a sphere of uniform density. If we consider a particle of mass m at point P at a distance (R – d) from the earth’s centre, where R is the radius of the earth and d is the depth below the earth’s surface, the gravitational force on the particle due to the earth is

F = \(\frac{G m M^{\prime}}{(R-d)^{2}}\), where ‘M’ is the mass of the sphere of radius (R – d).

because the outer spherical shell is not effective (Fig. 1.10). In this case, the acceleration due to gravity is

where M is the mass of the earth. Thus, g decreases as d increases. It is less than that at the earth’s surface (\(\frac{G M}{R^{2}}\)) At the earth’s centre, d = R
∴ g = 0.

[Note : The formulae given in the answer are not given in the textbook. The formula density = \(\frac{\text { mass }}{\text { volume }}\) is used to find M’.]

Std 10 Science Chapter 1 Gravitation Question Answer Question 4.
Let the period of revolution of a planet at a distance R from a star be T. Prove that if it was at a distance of 2R from the star, its period of revolution will be \(\sqrt{8} T\).
Answer:
T= \(\frac{2 \pi}{\sqrt{G M}} \quad r^{3 / 2}\), where T = period of revolution of a planet around the Sun, M = mass of the Sun, G = gravitational constant and r = radius of the orbit assumed to be circular = distance of the planet from the Sun.
For r = R, T =T₁.

Class 10 Science 1 Chapter 1 Gravitation Question 5.
Solve the following examples.
(a) An object takes 5 s to reach the ground from a height of 5 m on a planet. What is the value of g on the planet?
Solution:
Data: u = 0 m/s, s = 5m, t = 5s, g = ?

(b) The radius of planet A is half the radius of planet B. If the mass of A is M_A, what must be the mass of B so that the value of g on B is half that of its value on A? (Practice Activity Sheet – 4)
Solution:
Data : R_A = R_B/2, gB = \(\frac{1}{2}\) g_A, M_B = ?

(c) The mass and weight of an object on the earth are 5 kg and 49 N respectively. What will be their values on the moon? Assume that the acceleration due to gravity on the moon is l/6th of that on the earth.
Solution:
Data: m = 5 kg, W = 49 N,
gM = \(\frac{g_{E}}{6}\),m (on the moon) = ?, W(on the moon) = ?
(i) The mass of the object on the moon = the mass of the object on the earth = 5 kg
(ii) W = mg

(weight of the object on the moon).

(d) An object thrown vertically upwards reaches a height of 500 m. what was its initial velocity? How long will the object take to come back to the earth? Assume g = 10 m/s²
Solution:
100 mn/s and 20 s

(e) A ball falls off a table and reaches the ground in 1 s. Assuming g = 10 m/s², calculate its speed on reaching the ground and the height of the table.
Solution:
Data: t = 1s, g = 10 m/s², u = 0 m/s,
s = ?, v = ?
(i) s = ut + \(\frac{1}{2}\)gt²
= \(\frac{1}{2}\)gt² for u = 0 m/s
∴ s = \(\frac{1}{2}\) × 10 m/s² × (1s)²
=5 m
∴ The height of the table = 5 m.

(ii) v = u +at = u + gt
= 0 m/s + 10 m/s² × 1 s
= 10m/s
∴ The velocity of the ball on reaching the ground = 10 m/s.

(f) The masses of the earth and moon are 6 × 10²⁴ kg and 7.4 × 10²² kg, respectively. The distance between them is 3.84 × 10⁵ km. Calculate the gravitational force of attraction between the two. Use G = 6.7 × 10^-11 N.m² kg^-2.
Solution:
Data : m₁ = 6 × 10²⁴ kg,
m₂ = 7.4 × 10²² kg,
r = 3.84 × 10⁵ km = 3.84 × 10⁸ m,
G = 6.7 × 10^-11 N.m² kg^-2, F = ?

This is (the magnitude of) the gravitational force between the earth and the moon.

(g) The mass of the earth is 6 × 10²⁴ kg. The distance between the earth and the Sun is 1.5 × 10¹¹ m. If the gravitational force between the two is 3.5 × 10²² N, what is the mass of the Sun? (Use G = 6.7 × 10^-11 N.m² kg^-2)
Solution:
Data : m₁ = 6 × 10²⁴ kg,
r = 1.5 × 10¹¹ m, F = 3.5 × 10²² N,
G = 6.7 × 10^-11 N.m²kg^-2, m₂ = ?

= 1.96 × 10³⁰ kg (mass of the sun)

Gravitation Class 10 Exercise Answers Project:
Take weights of five of your friends. Find out what their weights will be on the moon and the Mars.
Answer:
Help: The weight of a body
(i) On the earth. W₁ = mg₁
(ii) on the moon, W₂ = mg₂
(iii) on Mars, W₃ = mg₃
∴ W₂ = W₁ × \(\frac{g_{2}}{g_{1}}\) and W₃ = W₁ × \(\frac{g_{3}}{g_{1}}\)
Now, g₁ = 9.81 m/s², g₂ = 1.67 m/s² and g₃ = 3.72 m/s²
If W₁= 500 N,
W₂ = 500 × \(\frac{1.67}{9.81}\)N = 85.12N(approx.)
and W₃ = 500 × \(\frac{3.72}{9.81}\)N = 189.6 N (approx.)

Can you recall? (Text Book Page No. 1)

10th Class Science Part 1 Chapter 1 Gravitation Exercise Question 1.
What are the effects of a force acting on an object? (Note: a body ≡ an object)
Answer:

A force can set a body in motion. For example, if a ball at rest on the floor is pushed, it rolls on the floor.
A force can stop a moving body. For example, a moving bicycle can be brought to rest by application of brakes.
A force acting on a body can change the speed of the body. For example, when brakes are applied to a moving bicycle, its speed decreases due to the friction between the brake shoes and the rim of the tire.
A force can change the direction of motion of the body. For example, in a uniform circular motion of a body, the direction of motion of the body keeps on changing due to the applied force.
A force can change the speed as well as the direction of motion of the body. For example, when a ball bowled by a bowler is hit by a batsman, there occurs a*change in the speed as well as the direction of motion of the ball.
A force can change the shape and size of the body on which it acts. For example, when a rubber ball is pressed, it gets deformed and hence no longer remains spherical. Also, there can be a decrease in its volume.

1 Gravitation Exercise Question 2.
What types of forces are you familiar with?
Answer:
The gravitational force between the earth and the moon, the electromagnetic force between two charged particles in motion, the nuclear force between a proton and a neutron in the nucleus of an atom.

Gravitation 10th Class Exercise Question 3.
What do you know about the gravitational force?
Answer:
The gravitational force is a universal force, i.e., it acts between any two objects in the universe.

Can you recall? (Text Book Page No. 1)

Science Part 1 Gravitation Exercise Question 1.
What are Newton’s laws of motion?
Answer:
(1) Newton’s first law of motion: An object continues to remain at rest or in a state of uniform motion along a straight line unless an external unbalanced force acts on it.

(2) Newton’s second law of motion: The rate of change of momentum is proportional to the applied force and the change of momentum occurs in the direction of the force.

(3) Newton’s third law of motion: Every action force has an equal and opposite reaction force that acts simultaneously.
[Note: Equal in magnitude and opposite in direction.]

Use your brainpower! (Text Book Page No. 4)

10th Science Part 1 Gravitation Exercise Question 1.
If area ESF in figure 1.5 is equal to area ASB, what will you infer about EF?
Answer:
The time taken by the planet to move from E to F equals the time taken by the planet to move from A to B.

Use your brainpower (Text Book Page No. 7)

Gravitation Exercise 10th Class Question 1.
According to Newton’s law of gravitation, every object attracts every other object.
Thus, if the earth attracts an apple towards itself, the apple also attracts the earth towards itself with the same force. Why then does the apple fall towards the earth, but the earth does not move towards the apple?
Answer:
The earth and the apple move towards each other, but the magnitude of the displacement of the earth is negligible relative to that of the apple. Also the observer is located on the earth.
[Note: The mass of the earth is far greater than that of an apple. Hence, the magnitude of the acceleration of the earth is negligible relative to that of the apple.]

Gravitation Class 10 Question And Answer Question 2.
The gravitational force due to the earth also acts on the moon because of which it revolves around the earth. Similar situation exists for the artificial satellites orbiting the earth. The moon and the artificial satellites orbit the earth. The earth attracts them towards itself but unlike the falling apple, they do not fall on the earth, why?
Answer:
This is because of the velocity of the moon and the satellites along their orbits. If this velocity was not there, they would have fallen on the earth.

Think about it (Text Book Page No. 8)

Std 10 Science Chapter 1 Gravitation Exercise Question 1.
What would happen if there were no gravity?
Answer:
There would be no gravitational attraction between any two particles and hence no formation of the solar system, galaxy, etc.

Science 1 Gravitation Question 2.
What would happen if the value of G was twice as large?
Answer:
The gravitational force between any two particles would become double, also the value of g would become double.

Can you tell? (Text Book Page No. 8)

Gravitation Class 10 Exercise Question 1.
What would be the value of g on the surface of the earth if its mass was twice as large and its radius half of what it is now? (March 2019)
Answer:

∴ g₂ = 8g₁
Thus, the value of g on the surface of the earth would be eight times the present value.

Think about it (Text Book Page No. 9)

Std 10 Science Chapter 1 Gravitation Answers Question 1.
Will the direction of the gravitational force change as we go inside the earth?
Answer:
No.

Gravitation Class 11 Exercise Solutions State Board Question 2.
What will be the value of g at the centre of the earth?
Answer:
Zero.

Use your brain power! (Text Book Page No. 10)

10th Ssc Science Chapter 1 Gravitation Question 1.
Will your weight remain constant as you go above the surface of the earth?
Answer:
No. As we go above the surface of the earth, our weight will go on decreasing.

Class 10 Science Chapter 1 Gravitation Question 2.
Suppose you are standing on a tall ladder. If your distance from the centre of the earth is 2R, what will be your weight?
Answer:

= \(\frac{1}{4}\left(\frac{G M m}{R^{2}}\right)\)

Use your brain power! (Text Book Page No. 12)

Gravitation Class 11 Maharashtra Board Question 1.
According to Newton’s law of gravitation, the earth’s gravitational force is higher on an object of larger mass. Why doesn’t that object fall down with higher velocity as compared to an object with lower mass?
Answer:
F = ma and F = \(\frac{G M m}{r^{2}}\)
∴ Acceleration, a = \(\frac{G M}{r^{2}}\). This is independent of the mass (m) of the object. Hence, an object of larger mass and an object of lower mass fall down with the same velocity.

Use your brain power! (Text Book Page No. 6)

Question 1.
Assuming the acceleration in Example 2 above remains constant, how long will Mahendra take to move 1 cm towards Virat?
Answer:
Here, u = 0

= 1935 s = 32 minutes 15 seconds.

Fill in the blanks with appropriate words and write the completed sentences :

Question 1.
The ratio g(earth)/g(moon) is equal to……..
Answer:
The ratio g(earth)/g(moon) is equal to 6 (approximately)

Question 2.
The value of the acceleration due to gravity……..as we move from the equator to a pole.
Answer:
The value of the acceleration due to gravity increases as we move from the equator to a pole.

Question 3.
If the earth shrinks to half of its radius, its mass remaining the same, the weight of an object on the earth will become……..times.
Answer:
If the earth shrinks to half of its radius, its mass remaining the same, the weight of an object on the earth will become four times.

Question 4.
The SI unit of weight is the……..
Answer:
The SI unit of weight is the newton.

Question 5.
The CGS unit of weight is the……..
Answer:
The CGS unit of weight is the dyne

Question 6.
The weight of a body is ……..at the poles.
Answer:
The weight of a body is maximum at the poles.

Question 7.
Outside the earth, the weight of a body varies as……..
Answer:
Outside the earth, the weight of a body varies as 1/(R + h)²

Question 8.
Due to the …….. force, the earth attracts all objects towards it.
Answer:
Due to the gravitational force, the earth attracts all objects towards it. Gravitational

Question 9.
The acceleration due to gravity does not depend on the …….. of the body.
Answer:
The acceleration due to gravity does not depend on the mass of the body. Mass

Question 10.
According to Kepler’s first law, the orbit of a planet is …….. with the Sun at one of the……..
Answer:
According to Kepler’s first law, the orbit of a planet is an ellipse with the Sun at one of the foci

Question 11.
According to Kepler’s second law, the line joining the planet and the Sun …….. in equal intervals of time.
Answer:
According to Kepler’s second law, the line joining the planet and the Sun Sweeps equal areas in equal intervals of time.

Question 12.
According to Kepler’s third law T² ∝ rⁿ, where n = ……..
Answer:
According to Kepler’s third law T² ∝ rⁿ, where n = 3

Question 13.
For a freely falling object, we can write Newton’s second equation of motion as ……..
Answer:
For a freely falling object, we can write Newton’s second equation of motion as S = \(\frac{1}{2}\)gt²

Question 1.
(A) Write the proper answer in the square. (Practice Activity Sheet – 1)

If this F = x
Then F =
Answer:
F = \(\frac{x}{4}\)

(B) Write the proper answer in the square. (March 2019)

If F = \(\frac{G m_{1} m_{2}}{d^{2}}\),
then F =
Answer:
F = \(\frac{G m_{1} m_{2}}{9 d^{2}}\)

Choose the correct alternative and rewrite the statements:

Question 1.
The gravitational force between two particles separated by a distance r varies as ……..
(a) \(\frac{1}{r}\)
(b) r
(c) r²
(d) \(\frac{1}{r^{2}}\)
Answer:
(d) \(\frac{1}{r^{2}}\)

Question 2.
In the usual notation, the acceleration due to gravity at a height h from the surface of the earth is ……..

Answer:
(c) g = \(\frac{G M}{(R+h)^{2}}\)

Question 3.
The SI unit of the universal constant of gravitation is ……..
(a) N.m²/kg²
(b) N.kg²/m²
(c) m/s²
(d) kg.m/s²
Answer:
(a) N.m²/kg²

Question 4.
The escape velocity of a body from the earth’s surface, v_sec = …….

Answer:
(c) \(\sqrt{\frac{2 G M}{R}}\)

Question 5.
How much will a person with 72 N weight on the earth, weigh on the moon? (Practice Activity Sheet-1)
(a) 12 N
(b) 36 N
(c) 21 N
(d) 63 N
Answer:
(a) 12 N

Question 6.
What will be the weight of a person on the earth, who weighs 9N on the moon? (Practice Activity Sheet – 2)
(a) 3 N
(b) 15 N
(c) 45 N
(d) 54 N
Answer:
(d) 54 N

State whether the following statements are True or False : (If a statement is false, correct it and rewrite it.)

Question 1.
If the separation between two particles is doubled, the gravitational force between the particles becomes half the initial force.
Answer:
False. (If the separation between two particles is doubled, the gravitational force between the particles becomes \(\frac{1}{4}\) times the initial force.)

Question 2.
The CGS unit of the universal constant or gravitation is the dyne cm²/gram²?
Answer:
True.

Question 3.
At the centre of the earth, the value of the acceleration due to gravity becomes zero.
Answer:
True.

Question 4.
The weight of a body is minimum at the poles.
Answer:
False. (The weight of a body is maximum at the poles.)

Question 5.
Mass is a vector quantity.
Answer:
False. (Mass is a scalar quantity.)

Question 6.
weight is a vector quantity.
Answer:
True.

Question 7.
g has maximum value at the equator.
Answer:
False. (g has maximum value at the poles.)

Question 8.
Outside the earth, g varies as 1/(R + h)².
Answer:
True.

Question 9.
The value of G changes from place to place.
Answer:
False. (The value of G is the same throughout the universe.)

Question 10.
The value of g increases with altitude.
Answer:
False. (The value of g decreases with altitude.)

Question 11.
The escape velocity of a body does not depend on the mass of the body.
Answer:
True

Question 12.
The mass of a body is the amount of matter present in it.
Answer:
True

Match the following :

Answer:
(1) Escape velocity : \(\sqrt{\frac{2 G M}{R}}\)
(2) Gravitational acceleration : \(\frac{G M}{r^{2}}\) (r ≥ R)
(3) Gravitational potential energy : \(\frac{-G M m}{R+h}\)
(4) Gravitational force : \(\frac{G m_{1} m_{2}}{r^{2}}\)

Answer the following questions in one sentence each:

Question 1.
State the SI and CGS units of G.
Answer:
The SI unit of G is N.m²/kg² and CGS unit is the dyne.cm²/g².

Question 2.
State any one characteristic of gravitational force.
Answer:
Gravitational force between two particles does not depend on the nature of the medium between them.

Question 3.
Name the force that keeps a satellite in the orbit around the earth.
Answer:
The gravitational force due to the earth keeps a satellite in the orbit around the earth.

Question 4.
Name the force due to which the earth revolves around the Sun.
Answer:
The earth revolves around the Sun due to the gravitational force of attraction exerted on it by the Sun.

Question 5.
What is the acceleration due to gravity at a height h ( = radius of the earth) from the surface of the earth? (g = 9.8 m/s²)
Answer:
The acceleration due to gravity at a height h ( = radius of the earth) from the surface of the earth is 2.45 m/s².

Question 6.
What is the relation between the SI unit of weight and the CGS unit of weight?
Answer:
The relation between the SI unit of weight (the newton) and the CGS unit of weight (the dyne) is 1 newton = 10⁵ dynes.

Question 7.
Write the formula for the centripetal force acting on a body performing circular motion.
Answer:
F = \(\frac{m v^{2}}{r}\)

Question 8.
Write the formula for the escape velocity of a body from the earth’s surface.
Answer:

Question 9.
What is the value of the acceleration due to gravity at the centre of the earth?
Answer:
Zero.

Question 10.
What are the factors on which the maximum height attained by a body thrown upwards depends?
Answer:
The initial velocity of the body, the acceleration due to gravity at that place, the buoyant force and frictional force due to air.

Some of the important terms in chapter Gravitation are given in the following box. Find them :

Answer:
(1) centripetal force
(2) escape velocity
(3) periodic time
(4) gravitational constant.

Answer the following questions:

Question 1.
What is centripetal force?
(OR)
Define centripetal force.
Answer:
In uniform circular motion of a body, the force acting on the body is directed towards the centre of the circle. This force is called centripetal force.

Question 2.
Give one example of centripetal force.
Answer:
The moon revolves around the earth due to the gravitational force exerted on it by the earth. This force is directed towards the centre of the earth and is thus a centripetal force.

Question 3.
Name the source responsible for the motion of a planet around the Sun.
Answer:
A planet revolves around the Sun due to the gravitational force exerted on it by the Sun.

Answer the following questions:

Question 1.
In the following figure, an orbit of a planet around the Sun (S) has been shown. AB and CD are the distances covered by the planet in equal time. Lines AS ad CS sweep equal areas in equal intervals of time. Hence, areas ASB and CSD are equal. (Practice Activity Sheet-1)
(a) Which laws do we understand from the above description?
(b) Write the law regarding the area swept.
(c) Write the law T² ∝ r³ in your words.

Answer:
(a) From the given description we understand Kepler’s three laws.
(b) Kepler’s law of areas: The line joining the planet and the Sun sweeps equal areas in equal intervals of time.
(c) Kepler’s law of periods: The square of the period of revolution of a planet around the Sun is directly proportional to the cube of the mean distance of the planet from the Sun.

Question 2.
Identify the law shown in Fig. 1.7 and state the three respective laws. (Practice Activity Sheet – 3)

Answer:
(a) From the given description we understand Kepler’s three laws.
(b) Kepler’s law of areas: The line joining the planet and the Sun sweeps equal areas in equal intervals of time.
(c) Kepler’s law of periods: The square of the period of revolution or a planet around the Sun is directly proportional to the cube of the mean distance of the planet from the Sun.

Question 3.
Explain the term gravitational force. What is gravitation?
Answer:
There exists a force of attraction between any two particles of matter in the universe such that the force depends only on the masses of the particles and the separation between them. It is called the gravitational force and the mutual attraction is called gravitation.

Question 4.
State Newton’s universal law of gravitation. Express it in mathematical form.
Answer:
Newton’s universal law of gravitation :
Every object in the Universe attracts every other object with a definite force. This force is directly proportional to the product of the masses of the two objects and inversely proportional to the square of the distance between them.

Mathematical form: Consider two objects of masses m₁ and m₂. We assume that the objects are very small spheres of uniform density and the distance r between their centers is very large compared to the radii of the spheres (Fig. 1.8).

The magnitude (F) of the gravitational force of attraction between the objects is directly proportional to m₁m₂ and inversely proportional to r²
∴ F ∝ \(\frac{m_{1} m_{2}}{r^{2}}\)
∴ F = \(G\frac{m_{1} m_{2}}{r^{2}}\)
where G is the constant of proportionality, called the universal gravitational constant.
[Note: In the textbook, the word object/body is used.
Newton’s law of gravitation applies to particles.]

Question 5.
(i) Why is the constant of gravitation called a universal constant?
(ii) Newton’s law of gravitation is called the universal law of gravitation. Why?
Answer:
(i) The value of the constant of gravitation does not change with the nature, mass or the size of the material particles. It does not vary with the distance between the two particles. It is also independent of the nature of the medium between the two particles. Hence, it is called a universal constant.

(ii) As the law of gravitation given by Newton is applicable throughout the universe and to all particles, it is called universal law.

[ Note: The centre of mass of an object is the point inside or outside the object at which the total mass of the object can be assumed to be concentrated to study the effect of an applied force. The centre of mass of a spherical object having uniform density is at its geometrical centre. The centre of mass of an object having uniform density is at its centroid. If the two bodies are spherical and of uniform density, the gravitational force between them is always along the line joining the centres of the two bodies and the distance between the centres is taken to be r. When the bodies are not spherical or have irregular shape or have nonuniform density, the force is along the line joining their centres of mass and r is taken to be the distance between the two centres of mass.]

Question 6.
If the distance between two bodies is increased by a factor of 5, (i) by what factor will the gravitational force change if the masses are kept constant? (ii) by what factor will the mass of one of them have to be altered, keeping the other mass the same, to maintain the same gravitational force between the two bodies?
Answer:
If the distance between two bodies is increased by a factor of 5,
(i) the gravitational force between the bodies will decrease by a factor of 25 if the masses of the bodies are kept constant.
(ii) the mass of one of them will have to be increased by a factor of 25, keeping the mass of the other body the same, to maintain the same gravitational force between the two bodies.
[Note : Gravitational force F ∝ \(\frac{1}{r^{2}}\) and F ∝ m₁m₂.]

Question 7.
(i) Determine the SI unit of the universal constant of gravitation from the formula for the gravitational force between two particles. Hence, state the CGS unit of the constant of gravitation. (ii) Define G (universal gravitational constant).
Ans. (i) According to Newton’s law of gravitation, the gravitational force between two particles is
F = \(G\frac{m_{1} m_{2}}{r^{2}}\)
where m₁ and m₂ are the masses of the two particles, r is the distance between them and G is the universal constant of gravitation.
∴ G = \(\frac{F r^{2}}{m_{1} m_{2}}\)

The SI unit of force is the newton (N), that of distance is the metre (m) and that of mass is the kilogram (kg).
The SI unit of G is \(\frac{\mathrm{N} \cdot \mathrm{m}^{2}}{\mathrm{kg}^{2}}\).
The CGS unit of G is \(\frac{\text { dyne } \cdot \mathrm{cm}^{2}}{\mathrm{g}^{2}}\).

(ii) F = \(G\frac{m_{1} m_{2}}{r^{2}}\).
∴ G = \(\frac{F r^{2}}{m_{1} m_{2}}\)
If we take m₁ = m₂ = unit mass and r = unit distance, numerically, G = F, i.e., G (universal gravitational constant) represents the magnitude of the gravitational force of attraction between two unit masses, separated by a unit distance.

Question 8.
State the importance of Newton’s universal law of gravitation.
Answer:
The importance of Newton’s universal law of gravitation :
This law explains successfully, i.e., with great accuracy,

The force that binds the objects on the earth to the earth
The motion of the moon and artificial satellites around the earth
The motion of the planets, asteroids, comets, etc., around the Sun
The tides of the sea due to the moon and the Sun.

Question 9.
Compare the gravitational force on a body of mass 1 kg due to the earth with the force on the same body due to another body of mass 1 kg at a distance of 1 m from the first body. (Mass of the earth = 6 × 10²⁴ kg, radius of the earth = 6400 km)
Answer:
In the first case, m₁ = 1kg,
m2 = 6 × 10²⁴ kg and r = 6400 km = 6.4 × 10⁶ m
The gravitational force on the body.

= \(\frac{G \times 6 \times 10^{24} \mathrm{kg}^{2}}{(6.4)^{2} \times 10^{12} \mathrm{m}^{2}}\)
In second case, m₁ = 1 kg
m₂ = 1 kg and r = 1m
Gravitational force on the body,

Question 10.
Explain the term the earth’s gravitational force.
(OR)
Write a short note on the earth’s gravitational force.
Answer:
The earth attracts every object towards it because of the gravitational force. As the earth’s centre of mass is at its centre, the gravitational force exerted by the earth on an object is directed towards the earth’s centre. Hence, an object released from a point above the earth’s surface falls vertically downward towards the earth.

If an object is thrown vertically upward, its velocity goes on decreasing due to the earth’s gravitational force on the object. At one stage, the velocity of the body becomes zero and later the body falls back to the earth.

Question 11.
Take two balls of different masses, go to the top of a building, drop them simultaneously and observe what happens to the balls.
Answer:
The balls reach the ground almost at the same time.

Question 12.
Take two similar pages from your notebook. Crumple one paper and allow this and the other paper to fall on the ground simultaneously. What do you observe?
Answer:
The crumpled paper reaches the ground before the other one.

Question 13.
Take a feather and a paper. Allow them to fall to the ground simultaneously. Which will reach the ground earlier? Why?
Answer:
There is no unique answer. It depends on the feather and paper. Upthrust due to air and force due to friction with air play very important roles here. The acceleration of a body depends on the resultant of the earth’s gravitational force on the body and the upthrust and the force of friction due to air.

Question 14.
From Newton’s law of gravitation, derive the formula for the acceleration due to gravity.
Answer:
Suppose that a body of mass m is released from a distance r from the centre (O) of the earth (Fig. 1.9). Let M be the mass of the earth. According to Newton’s law of gravitation, the magnitude of the earth’s gravitational force acting on the body Is
F = G\(\frac{M m}{r^{2}}\)
where G is the universal constant of gravitation.

The acceleration produced by this force, force F

This is the formula for the acceleration due to gravity or the gravitational acceleration due to the earth. This acceleration is directed towards the earth’s centre.

If h denotes the altitude, r = R + h, where R is the radius of the earth.
∴ g = \(\frac{G M}{(R+h)^{2}}\)
For a body on the earth’s surface, h = 0 ∴ g = \(\frac{G M}{R^{2}}\)
[Note: When we consider the gravitational interaction between the earth and a body on the surface of the earth or at some height above the surface of the earth, for many practical purposes we can assume that the earth behaves as if its mass were concentrated at the earth’s centre. The proof is not expected here.]

Question 15.
Explain the factors affecting the value of g.
Answer:
The value of the acceleration due to gravity, g, changes from place to place on the earth. It also varies with the altitude and depth below the earth’s surface. The factors affecting the’ value of g are the shape of the earth, altitude and depth below the earth’s surface.

(1) The earth is not perfectly spherical. It is somewhat flat at the poles and bulging at the equator. At the surface of the earth, the value of g is maximum (9.832 m/s²) at the poles as the polar radius is minimum, while it is minimum (9.78 m/s²) at the equator as the equatorial radius is maximum.

(2) As the height (h) above the earth’s surface increases, the value of g decreases. It varies as \(\frac{1}{(R+h)^{2}}\), where R is radius of the earth.

(3) In the interior of the earth, on average, the value of g is less than that at the earth’s surface. As the depth below the earth’s surface increases, the value of g decreases and finally it becomes zero at the centre of the earth.

Question 16.
If g = GM/r², then where will the value^ of g be high, at Goa Beach or on the top of the Mount Everest? (Practice Activity Sheet – 3)
Answer:
The value of g will be high at Goa Beach.

Question 17.
Why does an object released from the hand, fall on the earth?
Answer:
When an object is held in the hand, the gravitational force acting on the object due to the earth is balanced by the person holding the object. When the object is released from the hand, it falls on the earth due to the earth’s gravitational force.

Question 18.
Does the value of g depend on the mass of the falling body? Why?
Answer:
The value of g does not depend on the mass of the falling body.
The reason is the gravitational force on a body due to the earth is directly proportional to the mass of the body and for a given force, the acceleration of a body is inversely proportional to the mass of the body.

Question 19.
Define mass. State its SI and CGS units.
Answer:
The mass of a body is the amount of matter present in it. Its SI unit is the kilogram (kg) and CGS unit is the gram (g).
[Note: Mass has only magnitude, not direction. Thus, it is a scalar quantity.]

Question 20.
Define weight. State its SI and CGS units.
Answer:
The weight of a body is defined as the force with which the earth attracts it. Its SI unit is the newton and CGS unit is the dyne.

[Note : In the usual notation, the magnitude of the weight of a body on the earth s surface is W = \(\frac{G m M}{R^{2}}\) = \(m\frac{G M}{R^{2}}\) = mg. Thus, W ∝ g. Hence, weight varies just like the acceleration due to gravity. It is maximum at the poles and minimum at the equator. It decreases with altitude (ft) and depth (d) below the earth’s surface. It becomes zero at the earth’s centre. At a height above the earth’s surface, W = \(\frac{G m M}{(R+h)^{2}}\) at a depth d below the earth’s surface, W = \(\frac{G m M(R-d)}{R^{3}}\). Weight has magnitude and direction (towards the earth’s centre). It is a vector quantity.]

Question 21.
As per the request of one of his friends from the equator, Rahul buys 100 grams of silver at the north pole. He hands it over to his friend at the equator. Will the friend agree with the weight of the silver bought? If not, why?
Answer:
The weight of a body is given by W = mg, where m is the mass of the body and g is the acceleration due to gravity, g varies from place to place. The value of g at the equator is less than that at the north pole (as well as the south pole). Hence, the weight of the silver bought at the north pole would be less when the silver is weighed at the equator. Therefore, Rahul’s friend will disagree about the weight of the silver.
[Note: The mass being independent of the value of g, Rahul’s friends will agree about the mass of the silver.]

Question 22.
What is the difference between mass and weight of an object? Will the mass and weight of an object on the earth be the same as their values on Mars? Why?
Answer:
The mass of an object is the amount of matter present in it. It is same everywhere in the Universe and is never zero. It is a scalar quantity and its SI unit is kg. The weight of an object is the force with which the earth (or any other planet/ moon/star) attracts it. It is directed towards the centre of the earth. The weight of an object is different at different places on the earth. It is zero at the earth’s centre. It is a vector quantity and its SI unit is the newton (N). The magnitude of weight = mg.

The mass of an object will be the same on the earth and Mars, but the weight will not be the same because the value of g on Mars is different from that on the earth.

Question 23.
Explain the term free fall and state the corresponding kinematical equations of motion in the usual notation.
Answer:
When a body falls in air, there are three forces acting on the body : (1) the gravitational force due to the earth, acting downward (2) the force of buoyancy (upthrust) due to air, acting upward I (3) the force due to friction with air (called air resistance), acting upward (being always in the direction opposite to that of the velocity of the body).

Under certain conditions, the force of buoyancy due to air and friction with air can be ignored compared to the gravitational force of the earth. In that case (near the earth’s surface) the body falls with almost uniform acceleration (g). Whenever a body moves under the influence of the force of gravity alone, it is said to be falling freely. Strictly speaking, this is true only if the body falls in vacuum.

The kinematical equations of motion, in the usual i notation, are
v = u + gt, s = ut + \(\frac{1}{2}\) gt² and v² = u² + 2gs.
If the initial velocity (u) of the body is zero,
v = gt, s = \(\frac{1}{2}\)gt² and v² = 2 gs.

Question 24.
During a free fall, will a heavier object accelerate more than a lighter one?
Answer:
No. The two objects will have the same acceleration.

Question 25.
If you had to calculate the mass of the earth, how would you do it?
Answer:
If the acceleration due to gravity (g), the constant of gravitation (G) and the radius of the earth (R) are known, the mass of the earth (M) can be calculated using the formula g = \(\frac{G M}{R^{2}}\)

Question 26.
What is gravitational potential energy?
(OR)
Define gravitational potential energy.
Write the formula for it.
Answer:
The energy stored in a body due to the gravitational force between the body and the earth is called the gravitational potential energy.

Gravitational potential energy of a body of mass m = \(-\frac{G M m}{R+h}\), where G = gravitational constant, M = mass of the earth, R = radius of the earth, h = height of the body from the surface of the earth.

[Note : As the body is bound to the earth due to the earth’s gravitational froce, the gravitational potential energy of the body is negative. If the body is given kinetic energy equal to \(\frac{G M m}{R+h}\) the body will overcome the earth’s gravitational force. It will then move to infinity and come to rest there.]

Question 27.
What is escape Velocity?
(OR)
Define escape velocity.
Answer:
When a body is thrown vertically upward from the surface of the earth, the minimum initial velocity of the body for which the body is able to overcome the downward pull by the earth and can escape the earth forever is called the escape velocity.

Question 28.
Explain the term escape velocity.
(OR)
Write a short note on escape velocity.
Answer:
In general, when a body is thrown vertically upward from the earth’s surface, its velocity goes on decreasing and after some time the body falls back to the ground. If its initial velocity is increased, the maximum height attained by it is more, but it does fall back to the ground. If the initial velocity is increased continuously, for a particular initial velocity, the body can overcome the earth’s gravitational force and move to infinity and come to rest there. This velocity is called the escape velocity.

Question 29.
Using the law of conservation of energy, obtain the expression for the escape velocity.
Answer:
Here, we shall not consider the effects of air. Suppose a body of mass m is thrown vertically upward from the surface of the earth. Let the initial velocity of the body be the escape velocity (v_sec).

When the body is on the earth’s surface, its total energy Ex = kinetic energy + potential energy = \(\frac{1}{2} m v^{2} \text { esc }\) + \(\left(-\frac{G m M}{R}\right)\) where G = universal gravitational constant, M = mass of the earth and R = radius of the earth.
Thus, E₁ = \(\frac{1}{2} m v_{\mathrm{esc}}^{2}-\frac{G m M}{R}\)
When the body moves to infinity and comes to rest there, its total energy,

According to the law of conservation of energy,
E₁ = E₂.

This is the required expression.

Question 30.
Express escape velocity in terms of g and R.
Answer:
Escape velocity, vesc = \(\sqrt{\frac{2 G M}{R}}\)
Now, g = \(\frac{G M}{R^{2}}\)
∴ GM = gR²

Question 31.
Express escape velocity in terms of G, R and ρ (the earth’s density)
Answer:

Give scientific reasons:

Question 1.
If a feather and a stone are released from the top of a building simultaneously, the stone reaches the ground earlier than the feather.
Answer:
(a) The motion of a body falling in air accelerated due to the earth’s gravitational force on the body. The force due to buoyancy of air acts on the body in the upward direction. As the body falls, the friction with air opposes its motion.

(b) This opposition due to air depends on the size, shape, density and velocity of the body. It Is greater for a feather than for a stone. Hence, the stone has greater downward acceleration than the feather. Therefore, the stone reaches the ground earlier than the feather though ‘they are released simultaneously from the same height.

Question 2.
The weight of a body is different on different planets.
Answer:
(1) The weight of a body of mass m on the surface of a planet of mass M and radius R is
W = \(\frac{G m M}{R^{2}}\) usuai notation).

(2) For a given body, its mass is constant. G is the universal constant of gravitation. Different planets have different masses and radii such that the ratio (M/R²) is not the same. Hence, the weight of a body is different on different planets.

Question 3.
With a specific initial velocity, we can jump higher on the moon than on the earth.
Answer:
The acceleration due to gravity on the moon is about \(\frac{1}{6}\) of that on the earth. Hence, with a specific initial velocity, we can jump higher on the moon than on the earth. This can be seen from the equation h = u²/2g.

Distinguish between the following:

Question 1.
mass and weight (2) universal gravitational constant and gravitational acceleration of the earth.
Answer:
(1) Mass:

The mass of a body is the amount of matter present in it.
It has magnitude, but not direction.
It does not change from place to place.
It can never be zero.
Its SI unit is the kilogram.

Weight:

The weight of a body is the force with which the earth attracts it.
It has both magnitude and direction.
It changes from place to place.
It is zero at the centre of the earth.
Its SI unit is the newton.

Question 2.
Universal gravitational constant:

The universal gravitational constant numerically equals the force of attraction masses separated by a unit distance.
Its value remains constant throughout the universe.
It has magnitude but not direction.
Its SI unit is N.m²/kg².

Gravitational acceleration of the earth:

The gravitational between two unit acceleration of the earth is the acceleration produced in a body due to the gravitational force of the earth.
Its value changes from place to place.
It has both magnitude and direction.
Its SI unit is m/s²

Solve the following examples/numerical problems:
(G 6.67 × 10^-11 N.m²/kg², g = 9.8 m/s²)

Question 1.
The time taken by the earth to complete one revolution around the Sun is 3.156 × 10⁷ s. The distance between the earth and the Sun is 1.5 × 10¹¹ m. Find the speed of revolution of the earth.
Solution:
Data : T = 3.156 × 107 s,
r = 1.5 × 10¹¹ m, v =?

= 2.987 × 10⁴ m/s = 29.87 km/s
This is the speed of revolution of the earth.

Question 2.
Assuming that the earth performs uniform circular motion around the Sun, flnd the centripetal acceleration of the earth. [Speed of the earth =3 × 10⁴ m/s, distance between the earth and the Sun = 1.5 × 10¹¹ m]
Solution:
Data: v = 3 × 10⁴ m/s, r=1.5 × 10¹¹ m
Centripetal force = \(\frac{m v^{2}}{r}\) = ma
∴ Centripetal acceleration of the earth,

= 6 × 10^-3 m/s²
It is directed towards the centre of the Sun.

Question 3.
What will be the gravitational force on 60 kg man on the Moon, Mars and Jupiter? Are they the same? Why?
M (Moon) = 7.36 × 10²² kg, R (Moon) = 1.74 × 10⁶m,
M (Mars) = 6.4 × 10²³ kg, R (Mars) = 3.395 × 10⁶ m,
M (Jupiter) = 1.9 × 10²⁷ kg.
R (Jupiter) = 7.15 × 10⁷ m,
G = 6.67 × 10^-11 N.m/kg²
Solution:
(1) Data : m₁ = 60 kg, m₂ = 7.36 × 10²² kg,
R = 1.74 × 10⁶ m, F = ?

= 97.29 N
On the moon’s surface, the gravitational force on the man due to the moon = 97.29 N.

(2) Data : m₁ = 60 kg, m₂ = 6.4 × 10²³ kg,
R = 3.395 × 10⁶m, F = ?

= 222.2 N
On the surface of Mars, the gravitational force on the man due to Mars = 222.2 N.

(3) Data : m₁ = 60 kg, m₂ = 1.9 × 10²⁷ kg,
R = 7.15 × 10⁷ m, F = ?

= 1487 N
On the surface of Jupiter, the gravitational force on the man due to Jupiter = 1487 N.

Thus, the forces on the man are not the same because the ratio (M/R²) is not the same in the case of the moon, Mars, and Jupiter.

Question 4.
Mahendra and Virat are sitting at a distance of 1 meter from each other. Their masses are 75 kg and 80 kg respectively. What is the gravitational force between them? G = 6.67 × 10^-11 N.m²/kg². (Practice Activity Sheet – 3)
Solution:
Given: r = 1 m,
m₁ = 75 kg,
m₂ = 80 kg
G = 6.67 × 10-11 N.m²/kg²

= 4.002 × 10^-7 N
The gravitational force between Mahendra and Virat is 4.002 × 10^-7 N.

Question 5.
Spheres A and B of uniform density have masses 1 kg and 100 kg respectively. Their centres are separated by 100 m. (i) Find the gravitational force between them, (ii) Find the gravitational force on A due to the earth, (iii) Suppose A and B are initially at rest and A can move freely towards B. What will be the velocity of A one second after it starts moving towards B? How will this velocity change with time? How much time will A take to move towards B by 1 cm? (iv) if A begins to fall, starting from rest, due to the earth’s downward pull, what will be its velocity after one second? How much time will it take to fall through 1cm?
[M_(earth) = 6 × 10²⁴ kg, R_(earth) = 6400 km]
Solution:Data: m₁ = 1 kg, m₂ = 100 kg, r = 100 m,
M =6 × 10²⁴ kg,
R = 64o0 km = 6400 × 10³ m,
t = 1 s, s = 1 cm = 1 × 10^-2 m,
G = 6.67 × 10^-11 N.m2/kg
F₁ =?, F₂ =?, v₁ =?, t₁ =?, v₂ =?, t₁ =?

This is far greater than F₁.
(iii) Ignoring variation of acceleration with distance,

This velocity is directed from A to B. As the separation between A and B decreases, the acceleration of A and hence the velocity of A will increase.

Ignoring variation of acceleration with distance,

Question 6.
Two spheres of uniform density have masses 10 kg and 40 kg. The distance between the centres of the spheres is 200 m. Find the gravitational force between them.
Solution:
Data: m₁ = 10 kg, m₂ = 40 kg,
r = 200 m, G = 6.67 × 10^-11 N.m²/kg², F = ?

The gravitational force between the two spheres = 6.67 × 10^-13 N.

Question 7.
Find the gravitational force between a man of mass 50 kg and a car of mass 1500 kg separated by 10 m.
Solution: Data : m₁ = 50 kg, m₂ = 1500 kg,
r = 10 m, G = 6.67 × 10^-11 N.m²/kg², F = ?

= 5.0025 × 10^-8 N
The gravitational force between the man and the car = 5.0025 × 10^-8 N.

Question 8.
Find the magnitude of the gravitational force between the Sun and the earth. (Mass of the Sun = 2 × 10²⁴ kg, mass of the earth=6 × 10²⁴ kg and the thstance between the centres of the Sun and the earth 1.5 × 10¹¹ m,
G = 6.67 × 10^-11 N.m²/kg²)
Solution:
Data: m₁ = 2 × 10³⁰ kg,
m₂ = 6 × 10²⁴ kg, r = 1.5 × 10¹¹ m,
G = 6.67 × 10^-11 N.m²/kg², F =?

∴ F = 3.557 × 10²² N
The magnitude of the gravitational force between the Sun and the earth = 3.557 × 10²² N.

Question 9.
Find the magnitude of the acceleration due to gravity at the surface of the earth. (M= 6 × 10²⁴ kg, R = 6400 km)
Solution:
Data: M = 6 × 10²⁴ kg,
R = 6400km = 6.4 × 10⁶m,
G = 6.67 × 10^-11 N.m²/kg², g =?
g = \(\frac{G M}{R^{2}}\)

The magnitude of the acceleration due to gravity at the surface of the earth = 9.77 m/s².

Question 10.
The mass of an imaginary planet is 3 times the mass of the earth. Its diameter is 25600 km arid the earth’s diameter is 12800 km. Find the acceleration due to gravity at the surface of the planet, [g (earth) = 9.8 m/s²]
Solution:
Data: \(\frac{M_{2}(\text { planet })}{M_{1}(\text { earth })}\) = 3
D₁ (earth) = 12800 km

g₁ (earth) = 9.5 m/s², g₂ (planet) = ?

The acceleration due to gravity at the surface of the planet = 7.35 m/s².

Question 11.
If the acceleration due to gravity on the surface of the earth is 9.8 m/s², what will be the acceleration due to gravity on the surface of a planet whose mass and radius both are two times the corresponding quantities for the earth?
Solution:
Data: g_e = 9.8 m/s², M_p = 2M_e,
Rp = 2R_e, g_p = ?
Acceleration due to gravity, g = \(\frac{G M}{R^{2}}\)

acceleration due to gravity on the surface of the planet = 4.9 m/s².

Question 12.
A body is released from the top of a building of height 19.6 m. Find the velocity with which the body hits the ground.
Solution:
Data: h = 19.6 m, u = 0 m/s,
g = 9.8 m/s², s = 19.6 m, v = ?
v² = u² + 2 gs .
=2 gs …..(as u = 0 m/s)
= 2 × 9.8 m/s² × 19.6 m
= (19.6 m/s)²
∴ v = 19.6 m/s (downward velocity)
The velocity with which the body hits the i ground = 19.6 m/s (downward).

Question 13.
A stone on a bridge on a river falls into the river. If it takes 3 seconds to reach the surface of water, find (i) the velocity of the stone at the instant it touches the surface of water (ii) the height of the bridge from the surface of water.
Solution:
Data: u = 0 m/s, t = 3 s,
g = 9.8 m/s², v = ?, h = ?
(i) v = u + gt = 0 m/s + 9.8 m/s² × 3 s
= 29.4 m/s
The velocity of the stone at the instant it touches the surface of water = 29.4 m/s

(ii) s = ut + \(\frac{1}{2}\)gt²
= 0 m/s × 3 s + \(\frac{1}{2}\) (9.8 m/s²) (3 s)²
= 4.9 × 9 m = 44.1 m
∴ The height of the bridge from the surface of water = 44.1 m.

Question 14.
A stone is dropped from rest from the top of a building 44.1 m high. It takes 3 s to reach the ground. Use this information to 1 calculate g.
Solution:
Data: u = 0 m/s, h = 44.1 m
∴ s = 44.1 m, t = 3 s, g =?

It is the acceleration due to gravity.
g = 9.8 m/s².

Question 15.
A metal ball of mass 5 kg falls from a height of 490 m. How much time will it take to reach the ground? (g = 9.8 m/s²) (March 2019)
Solution:
Data: s = 490 m, a = g = 9.8 m/s²,
u = 0 m/s, s = ut + \(\frac{1}{2}\)at²
∴ 490 = 0 × t + \(\frac{1}{2}\) × 9.8 × t² = 4.9t²
∴ t² = \(\frac{490}{4.9}\)
∴ t = 10 s This is the required time.

Question 16.
If the weight of a body on the surface of the moon is 100 N, what is its mass? (g = 1.63 m/s²)
Solution:
Data: W= 100 N, g = 1.63 m/s², m = ?
∴ W = mg

∴ The mass of the body = 61.35 kg.

Question 17.
A 100 kg bag of wheat is placed on a plank of wood. What is the weight of the bag and what is the reaction force exerted by the plank?
Solution:
Data: m = 100 kg, g = 9.8 m/s²,
W = ?, reaction force = ?
Magnitude of the weight,
W = mg = 100 kg × 9.8 m/s² = 980 N
The weight of the bag = 980 N acting downward.
The reaction force exerted by the plank on the bag = 980 N acting upward.

Question 18.
Find the gravitational potential energy of a body of mass 10 kg when it is on the earth’s surface. [M(earth) = 6 × 1024 kg, it(earth) = 6.4 × 10⁶m, G = 6.67 × 10^-11 N. m²/kg²]
Solution:
Data: m = 10 kg, M = 6 × 10²⁴ kg,
R = 6.4 × 10⁶ m, G = 6.67 × 10^-11 N.m²/kg²
The gravitational potential energy of the body

Question 19.
If the body in Ex. (26) performs uniform circular motion around the earth at a height of 3600 km from the earth’s surface, what will be its gravitational potential energy?
Solution:
Here, h = 3600 km = 3.6 × 10⁶ m
∴ The gravitational potential energy of the body

Question 20.
A body of mass 20 kg is at rest on the earth’s surface, (i) Find its gravitational potential energy, (ii) Find the kinetic energy to be provided to the body to make it free from the gravitational influence of the earth. (g = 9.8 m/s², R = 6400 km)
Solution:
Data : m = 20 kg, g = 9.8 m/s²,
R = 6400 km = 6.4 × 10⁶ m
(i) The gravitational potential energy of the body =

= – 20 kg × 9.8 m/s² × 6.4 × 10⁶ m
= – 1.2544 × 10⁹ J.

(ii) To make the body free from the gravitational influence of the earth, it should be provided kinetic energy equal to 1.2544 × 10⁹ J.

Question 21.
If the body in Ex. (28) is moving at 100 m/s on-the earth’s surface, what will be its (i) kinetic energy (ii) total energy?
Solution:
Data : m = 20 kg, u = 100 m/s .
(i) The kinetic energy of the body
= \(\frac{1}{2}\)mv2 = \(\frac{1}{2}\) × 20 kg × (100 m/s)² = 10⁵ J.

(ii) The total energy of the body = kinetic energy + potential energy = 10⁵ J + (- 1.2544 × 10⁹ J)
= (1 – 12544) × 10⁵ J = – 12543 × 10⁵ J
= – 1.2543 × 10⁹ J.

Question 22.
A satellite of mass 100 kg performs uniform circular motion around the earth at a height of 6400 km from the earth’s surface. Find its gravitational potential energy. [g = 9.8 m/s², R = 6400 km]
Solution:
Data: m = 100 kg, g = 9.8 m/s²,
R = 6400 km = 6.4 × 10⁶ m, h = 6.4 × 10⁶ m
The gravitational potential energy of the satellite

Question 23.
Find the escape velocity of a body from the earth. [M(earth) = 6 × 10²⁴ kg, R (earth) = 6.4 × 10⁶ m, G = 6.67 × 10^-11 N.m²/ kg²]
Solution:
Data: M = 6 × 10²⁴ kg, R = 6.4 × 10⁶ m,
G = 6.67 × 10^-11 N.m²/kg²
The escape velocity of a body from the earth,

Question 24.
Find the escape velocity of a body from the earth. [R (earth) = 6.4 × 10⁶ m, ρ(earth) = 5.52 × 10³ kg/m³, G = 6.67 × 10^-11 N.m²/kg²]
Solution:
Data: R = 6.4 × 10⁶ m, ρ = 5.52 × 10³ kg/ m³, G = 6.67 × 10^-11 N.m²/kg²
The escape velocity of a body from the earth

Question 25.
Calculate the escape velocity of a body from the moon. [g(moon) = 1.67 m/s², R(moon) = 1.74 × 10⁶ m]
Solution:
Data: g = 1.67 m/s², R = 1.74 × 10⁶ m
The escape velocity of a body from the moon,

Question 26.
The mass of (an imaginary) planet is four times that of the earth and its radius is double the rathus of the earth. The escape velocity of a body from the earth is 11.2 × 10³ mn/s. Find the escape velocity or a body from the planet.
Solution:
Data: M₂ = 4M₁, R₂ = 2R₁,

This is the escape velocity or a body from the planet.

Numerical Problems For Practice

[G = 6.67 × 1O^-11 N.m²/kg², mass or the earth =6 × 10²⁴ kg, radius or the earthe 6.4 × 10⁶ m]

Question 1.
A satellite of mass 1000 kg revolves around the earth in a circular path. If the distance between the satellite and the centre of the earth is 40000 km, find the gravitational force exerted on the satellite by the earth.
Answer:
250.1 N

Question 2.
The masses of two spheres are 10 kg and 20 kg respectively. If the distance between their centers is 100 m, find the magnitude of the gravitational force between them.
Answer:
1.334 × 10^-12 N)

Question 3.
A satellite revolves around the earth along a circular path. If the mass of the satellite is 1000 kg and its distance from the center of the earth is 20000 km, find the magnitude of the earth’s gravitational force acting on the satellite.
Answer:
1000.5

Question 4.
Find the acceleration due to gravity at a distance of 20000 km from the center of the earth.
Answer:
1.0 m/s²

Question 5.
What is the weight of a body of mass 100 kg at the south pole? (g = 9.832 m/s²)
Answer:
983.2 N (downward)

Question 6.
What is the weight of a body of mass 20 kg at the equator? (g = 9.78 m/s²)
Answer:
195.6 N (downward)

Question 7.
A body is released from the top of a tower of height 50 m. Find the velocity with which the body hits the ground, (g = 9.8 m/s²)
Answer:
31.3 m/s (downward)

Question 8.
A body is thrown vertically upward with a velocity of 9.8 m/s. Calculate the maximum height attained by the body. (g = 9.8 m/s²)
Answer:
4.9 m

Question 9.
A particle of mass 10^-6 kg performs uniform circular motion. Its period is 10 s and the radius of the circle is 2 m. Find (i) the speed of the particle (ii) the centripetal acceleration of the particle (iii) the centripetal force on the particle.
Answer:
(i) 1.257 m/s
(ii) 0.79 m/s²
(iii) 7.9 × 10^-7 N

Question 10.
Find the gravitational potential energy of a body of mass 200 kg on the earth’s surface. [M(earth) = 6 × 10²⁴kg, R(earth) = 6400 km]
Answer:
-1.251 × 10¹⁰J

Question 11.
Find the gravitational potential energy of a body of mass 10 kg when it is at a height of 6400 km from the earth’s surface. [Given: a mass of the earth and radius of the earth. See Ex. 10 above.]
Answer:
-3.127 × 10⁸ J

Question 12.
Find the escape velocity of a body from the moon.
[M(moon) = 7.36 × 10²² kg, R(moon) = 1.74 × 10⁶ m]
Answer:
2.375 km/s

Class 10 Questions And Answers

10th Std Science Part 1 Questions And Answers:

Life Processes in Living Organisms Part – 1 Class 10 Questions And Answers Maharashtra Board

January 6, 2025January 5, 2025 by Bhagya

Balbharti Maharashtra State Board Class 10 Science Solutions Part 2 Chapter 2 Life Processes in Living Organisms Part – 1 Notes, Textbook Exercise Important Questions and Answers.

Std 10 Science Part 2 Chapter 2 Life Processes in Living Organisms Part – 1 Question Answer Maharashtra Board

Class 10 Science Part 2 Chapter 2 Life Processes in Living Organisms Part – 1 Question Answer Maharashtra Board

Question 1.
Fill in the blanks and explain the statements.
a. After complete oxidation of a glucose molecules, ……….. number of ATP molecules are formed.
Answer:
After complete oxidation of a glucose molecules, 38 number of ATP molecules are formed.

b. At the end of glycolysis, ……………… molecules are obtained.
Answer:
At the end of glycolysis, pyruvate molecules are obtained.

c. Genetic recombination occurs in ………… phase of prophuse of meiosis-I.
Answer:
Genetic recombination occurs in pachytene phase of prophase of meiosis-I.

d. All chromosomes are arranged parallel to equatorial plane of cell in …………. phase of mitosis.
Answer:
All chromosomes are arranged parallel to equutorial plane of cell in metaphase phase of mitosis.

e. For formation of plasma membrane, phospholipid molecules are necessary.
Answer:
For formation of plasma membrane, …………… molecules are necessary.

f. Our muscle cells perform ……………… type of respiration during exercise.
Answer:
Our muscle cells perform anaerobic type of respiration during exercise.

Question 2.
Write definitions.
a. Nutrition.
Answer:
Nutrition: The process of taking nutrients in the body and utilizing them by an organism is known as nutrition.

b. Nutrients.
Answer:
Nutrients: The substances like carbohydrates, proteins, lipids, vitamins, minerals etc. which are components of the food are called nutrients.

c. Proteins.
Answer:
Proteins: Protein is a macromolecule which is formed by many amino acids which are joined by peptide bonds.

d. Cellular respiration.
Answer:
Cellular respiration: Oxidation of glucose and other food components which takes place inside the cell in presence or absence of oxygen, is known as cellular respiration.

e. Aerobic respiration.
Answer:
Aerobic respiration: Cellular respiration taking place in presence of oxygen is known as aerobic respiration.

f. Glycolysis.
Answer:
Glycolysis: The process occurring in the cell where a molecule of glucose is oxidized in step by step process forming two molecules of each of pyruvic acid, ATP, NADH₂ and water, is called glycolysis.

Question 3.
Distinguish between
a. Glycolysis and TCA cycle
Answer:
Glycolysis:

The process of glycolysis occurs in the cytoplasm of the cell.
In glycolysis, one molecule of glucose is oxidized step-by-step to produce two molecules each of pyruvic acid, ATP, NADH₂ and water.
Glycolysis can take place in both aerobic and anaerobic respiration.
The first step in cellular respiration is glycolysis where glucose is converted into pyruvate.
Two molecules of pyruvate are obtained in glycolysis.
Two molecules of ATP are used up in glycolysis.
Four molecules of ATP are produced in glycolysis.
CO2 is not produced during glycolysis.

TCA cycle:

TCA cycle takes place in mitochondria.
In TCA cycle, molecule of acetyl-co-A is completely oxidized and in the process CO₂, H₂O, NADH₂, FADH₂ and ATP is produced.
TCA cycle takes place only during aerobic respiration.
The second step in cellular respiration is TCA cycle.
Pyruvate is converted into CO₂ and H₂O during TCA cycle.
ATP molecules are not used up in TCA cycle.
Two molecules of ATP are produced in TCA cycle.
CO₂ is produced in TCA cycle.

b. Mitosis and meiosis.
Answer:
Mitosis:

In mitosis the chromosome number does not change. Diploid cells remain diploid, without change.
One cell gives rise to two daughter cells in mitosis.
Karyokinesis of mitosis has four stages, viz. prophase, metaphase, anaphase and telophase.
Prophase of mitosis is not lengthy.
Genetic recombination does not happen in mitosis as there is no crossing over.
Mitosis is essential for growth and development.
Mitosis takes place both in somatic cells and germinal cells.

meiosis:

In meiosis, the chromosome number is reduced to half. The diploid cells become haploid.
One cell gives rise to four daughter cells in meiosis.
Meiosis has two major stages, viz. meiosis-I and meiosis-II. Each is further subdivided into prophase, metaphase, anaphase and telophase.
Prophase of meiosis-I is very lengthy.
Genetic recombination takes place in homologous chromosomes as there is crossing over during prophase-I.
Meiosis is essential for formation of gametes in sexual reproduction.
Meiosis takes place in only germinal cells. It does not take place in somatic cells.

c. Aerobic and anaerobic respiration.
Answer:
Aerobic respiration:

Oxygen is required for aerobic respiration.
Aerobic respiration takes place in nucleus as well as in cytoplasm.
At the end of aerobic respiration CO₂ and H₂O is formed.
Energy is produced in large amount in aerobic respiration.
Glucose is completely oxidized in aerobic respiration.
38 molecules of ATP are formed during aerobic respiration.
Chemical reaction:
C₆H₁₂O₆ + 6O₂ → 6H₂O + 6 CO₂ + 686 Kcal

Anaerobic respiration:

Oxygen is not required for anaerobic respiration.
Anaerobic respiration occurs only in the cytoplasm.
At the end of anaerobic respiration CO₂ and C₂H₅OH are formed.
Energy is produced in lesser amount in anaerobic respiration.
Glucose is incompletely oxidized in anaerobic respiration.
2 molecules of ATP are formed during anaerobic respiration.
Chemical reaction:
C₆H₁₂O₆ → 2 C₂H₅OH + 2 CO₂ + 50 Kcal

Question 4.
Give scientific reasons.
a. Oxygen is necessary for complete oxidation of glucose.
Answer:

When glucose is completely oxidized in aerobic cellular respiration, it produces 38 molecules of ATP.
In cellular respiration, three processes take place one after the other, these are glycolysis, Krebs cycle and electron transport chain reactions.
In absence of oxygen only glycolysis can occur but further two reactions will not take place.
If glycolysis occurs in absence of oxygen, it produces alcohol.
By anaerobic glycolysis only two molecules of ATP are produced.
This results in less energy supply to the body. Therefore, oxygen is necessary for complete oxidation of glucose.

b. Fibres are one of the important nutrients. (Board’s Model Activity Sheet)
Answer:

Fibres are indigestible substance.
They are thrown out along with other useless and undigested matter.
This aids in egestion. Some fibres also help in digestion of other substances.
Green leafy vegetables, fruits, cereals, etc. are considered as important in diet as they supply nutritious fibres.
Thus, fibres are considered as one of the important nutrients.

c. Cell division is one of the important properties of cells and organisms.
Answer:

Cell division is very essential for all the living organisms.
The growth and development is possible only due to cell division.
The emaciated body can be restored only through the cell division which adds new cells.
Offspring is produced only through the cell division that take place in parents.
In asexual reproduction, mitosis helps to give rise to new generation.
In sexual reproduction, meiosis helps to form haploid gametes.
All such functions show that cell division is one of the important properties of cells and organisms.

d. Sometimes, higher plants and animals too perform anaerobic respiration.
Answer:

When there is deficiency of oxygen in the surrounding, the aerobic respiration is not possible.
In such case, to survive, higher plants switch over to anaerobic respiration.
In some animal tissues in case of oxygen deficiency cells perform anaerobic respiration.

e. Krebs cycle is also known as citric acid cycle.
Answer:

Sir Hans Kreb proposed this cycle and hence it is called Krebs cycle.
These are series of cyclic chain reactions which begins with acetyl-coenzyme-A molecules which act with molecules of oxaloacetic acid.
The reactions are catalysed with the help of specific enzymes.
The first molecule formed in this reaction is called citric acid. Therefore, Krebs cycle is also called citric acid cycle.

Question 5.
Answer in detail.
a. Explain the glycolysis in detail.
Answer:

Carbohydrates are converted to glucose after the process of digestion is completed. The oxidation of glucose for releasing energy is called glycolysis which takes place in cytoplasm.
Glycolysis can occur in presence of oxygen or without oxygen too. The first type of glycolysis takes place in aerobic respiration and the second type is in anaerobic respiration.
In aerobic respiration, there is step-wise oxidation of glucose molecule forming two molecules each of pyruvic acid, ATP, NADH₂ and water.
Later the pyruvic acid formed in this process is converted into molecules of Acetyl-Coenzyme-A along with two molecules of NADH₂ and two molecules of CO₂.
During anaerobic respiration along with glycolysis there is fermentation too. This is incomplete oxidation of glucose and thus it results in formation of lesser energy.
The process of glycolysis was discovered by Gustav Embden, Otto Meyerhof, and Jacob Parnas. Therefore, in their honour, glycolysis is also called as Embden-Meyerhof-Parnas pathway (EMP pathway). For the discovery they had performed experiments on muscles.

b. With the help of suitable diagrams, explain the mitosis in detail.
Answer:
(1) There are two stages of mitosis. These are
(a) Karyokinesis or nuclear division and
(b) Cytokinesis or cytoplasmic division. Karyokinesis takes place in further four phases, viz prophase, metaphase, anaphase and telophase.

(a) Karyokinesis:
(i) Prophase: During prophase, condensation of chromosomes starts. The thin and thread like chromosomes start thickening. They are seen with their pair of sister chromatids. In animal cells the centrioles are seen to duplicate and move to opposite poles of the cell. Nuclear membrane and nucleolus disappear.

(ii) Metaphase: Chromosomes complete their condensation and each one is seen with its sister chromatids. The chromosomes are seen in equatorial plane of the cell. The spindle fibres are formed from polar region, where centrioles are present, and they attach themselves to the centromere of each chromosome. Nuclear membrane now disappears completely.

(iii) Anaphase: The centromeres of the chromosomes now divide forming two daughter chromosomes. The spindle fibres pull apart the chromosomes from equatorial region to the opposite poles. Chromosomes moving to the poles appear like bunch of bananas. One set of chromosomes reach each pole by the end of the anaphase.

(iv) Telophase: Telophase is reverse of events that occurred in prophase. The thickened chromosomes decondense. They again assume the thin and thread like appearance. Nuclear membrane and nucleolus appear again. The spindle fibres are completely lost. The cell looks as if it has two nuclei in one cytoplasm.

(b) Cytokinesis: In animal cells a notch develops in the middle of the cell. This notch goes on deepening down and later the cytoplasm divides into two. In plant cells, cell plate formation takes place and then cytokinesis takes place.

c. With the help of suitable diagrams, explain the five stages of prophase-I of meiosis.
Answer:

Prophase-I: Prophase – I of meiosis is much longer phase of the meiosis.
It is subdivided into 5 substages, namely leptotene, zygotene, pachytene, diplotene, and diakinesis.
(1) Leptotene: Initially the chromosomes start condensation and they become compact during leptotene.

(2) Zygotene: In zygotene, homologous chromosomes start pairing. This pairing is called synapsis. The structure called synaptonemal complex develops to hold chromosomes in place during this pairing. Each chromosome’s chromatid arm divides and forms structure called bivalent or tetrad.

(3) Pachytene: During pachytene stage, crossing over of non-sister chromatids of homologous chromosomes takes place. Genetic recombination is produced due to such exchange. The homologous chromosomes still remain paired together at the sites of crossing over.

(4) Diplotene: During diplotene, synaptonemal complex dissolves and the homologous chromosomes of the bivalents separate except at the point of crossing over. Thus, it looks like X-shaped structures called the chiasmata.

(5) Diakinesis: The last phase of prophase is for termination of chiasmata. The spindle fibres originate, and the cross-over homologous chromosomes are now separated. The nucleQlus disappears, and the nuclear envelope breaks down.

d. How do all the life processes contribute to the growth and development of the body?
Answer:

Different systems work in co-ordination with each other in the body of the living organisms. In human body the homoeostasis is very advanced.
Digestive system, respiratory system, circulatory system, excretory system, nervous system and all the external and internal organs in the bodywork independently but in coordination with each other.
The digested and absorbed nutrients of the food are transported to various cells with the help of circulatory system due to pumping of the heart. Simultaneously, the oxygen absorbed in the blood by lungs is also transported to each cell by RBCs.
Mitochondria in every cell brings about oxidation of nutrients and produce energy required for all of these functions.
The control is exercised by the nervous system on all these actions. This keeps the organism alive and helps in growth and development of the same.

e. Explain the Krebs cycle with reaction.
Answer:

Krebs cycle was proposed by Sir Hans Kreb. This cycle is named after him. It is also called tricarboxylic acid cycle or citric acid cycle.
The acetyl-coenzyme-A molecules enter the mitochondria located in the cytoplasm.
They participate in the chemical reactions taking place in Krebs cycle.
In the cyclic chemical reactions, acetyl- coenzyme-A is completely oxidised
It yields molecules of CO₂, H₂O, NADH₂, FADH₂ and ATP upon complete oxidation.

Question 5.
How energy is formed from oxidation of carbohydrates, fats and proteins?
Correct the dagram below.

Answer:
(1) First of all the dietary carbohydrates are digested in the digestive system with the help of various enzymes and converted into glucose. Similarly, proteins are converted into amino acids and fats are broken down into fatty aid and glycerol (alcohol).

(2) Oxidation of carbohydrates takes place during cellular respiration. Glucose is oxidized by three steps during aerobic respiration, viz. glycolysis, tricarboxylic acid cycle or Krebs cycle and electron transfer chain.

(3) From one molecule of glucose two molecules of each pyruvic acid, ATP, NADH₂ and water are formed during glycolysis. Pyruvic acid which is formed in this process is converted into Acetyl-Coenzyme-A along with release of two molecules each of NADH₂ and CO₂.

(4) In the next step, i.e. in TCA cycle, molecules of Acetyl-Co-A enter the mitochondria and a cyclic chain of reactions take place. Acetyl part of Acetyl- Co-A is completely oxidized through this cyclical process. The molecules CO₂, H₂O, NADH₂, FADH₂ are released in this process.

(5) In third step, i.e. in ETC reaction, NADH₂ and FADH₂ formed during first two steps are used for obtaining ATP molecules. 3 molecules of ATP are obtained from each NADH₂ molecule and 2 molecules of ATP from each FADH₂.

(6) Thus, one molecule of glucose upon complete oxidation in presence of oxygen yields 38 molecules of ATP. This is how from carbohydrates, energy is obtained.

(7) If carbohydrates are insufficient in diet, then proteins or lipids are used for energy production. Fatty acids derived from fats and amino acids derived from proteins are converted into Acetyl- Co-A. Acetyl-Co-A once again can yield energy through TCA cycle.

Corrected diagram:

Project:
With the help of information collected from internet, prepare the slides of various stages of mitosis and observe under the compound microscope.

Can you recall? (Text Book Page No. 12)

Question 1.
How are the food stuffs and their nutrient contents useful for body?
Answer:
The food stuffs are digested and converted into soluble nutrients. These nutrients are carried by blood to every cell of the body. The oxygen inhaled at the time of respiration is also carried to every cell. In the body cells, this oxygen carries out oxidation of nutrients and thus energy is produced. The energy helps the body to carry out all its functions. The nutrients help in the growth and development of the body.

Question 2.
What is the importance of balanced diet for body?
Answer:
Balanced diet has carbohydrates, proteins, fats, vitamins and minerals in the right proportion. Each nutrient carries a specific important function. In balanced diet all these nutrients are in right proportion. Since balanced diet is required for energy and nutrition, it is very important to maintain our health.

Question 3.
Which different functions are performed by muscles in body?
Answer:
There are three 4ypes of muscles in our body. The voluntary muscles bring about all the movements according to our will. Involuntary muscles bring about all vital activities of the body. The visceral organs are under the control of involuntary muscles. The cardiac muscles control the movements of heart. Carbohydrates and proteins are stored in muscles.

Question 4.
What is the importance of digestive juices in digestive system?
Answer:
Digestive juice contains different enzymes. Enzymes act as catalysts and bring about the chemical reactions at faster pace. The digestive juices of stomach make pH of digestive tract acidic while that of intestinal juice make it alkaline.

Question 5.
Which system is in action for removal of waste materials produced in human body?
Answer:
Excretory system helps in the removal of nitrogenous waste materials produced in the human body.

Question 6.
What is the role of circulatory system in energy production?
Answer:
Due to circulatory system, glucose from digestive system and oxygen from respiratory system is transported to every cell. Red blood cells carry the oxygen as the blood is pumped by the heart. In every cell with the help of oxygen, glucose molecules yield the energy by the process of oxidation.

Question 7.
How are the various processes occurring in the human body controlled? In how many ways?
Answer:
The nervous system and the endocrine system brings about control by nervous and chemical coordination in the body. Due to such coordination different functions of the body are carried out in sequential and controlled manner.

Use your barain power:

Question 1.
Many players are seen consuming some food stuffs during breaks of the game. Why may be the players consuming these food stuffs? (Text Book Page No. 12)
Answer:

Players require energy in greater amount.
They perspire heavily at the time of game or sport which results in the loss of water and electrolytes from their body.
This may affect their performance in sport. To prevent such unfavourable effect, they are given, juices or drinks.
This helps them to restore the balance of water and electrolytes in their body. It also gives enhanced energy required for the performance.

Question 2.
Many times, we experience dryness in mouth. (Text Book Page No. 17)
Answer:

In our body there is 65-70% water. This proportion is always maintained.
Sometimes we lose lots of water either through perspiration or due to unavailability of water for a long time. In such situations, we experience dryness in our mouth.
Dryness is a natural feeling which creates urge in us to drink water, thereby the proportion of water in the body is brought back to its normal levels.

Question 3.
Oral rehydration solution (Salt-sugar- water) is frequently given to persons experiencing loose motions. (Text Book Page No. 17)
Answer:

Loose motions cause lot of loss of water from the body.
This may result in dehydration. This can be lethal if ignored.
Especially in case of young children this is a very serious fatal problem.
Thus, to bring back the normal proportion of water and electrolytes, oral rehydration solution or ORS is given to the patient who suffers from loose motions.

Question 4.
We sweat during summer and heavy exercise. (Text Book Page No. 17)
Answer:

During summer, the environmental temperatures are high.
This causes rise in our body temperature. Exercising also cause rise in the temperature. But since we can regulate our body temperature to a constant level, the sweat, glands g6t automatically stimulated.
This induces perspiration.
The sweat evaporates and causes fall in the body temperature. Thus, for regulation of body temperature, we sweat during summer or even after heavy exercise.

Question 5.
What do you mean by diploid (2n) cell? (Text Book Page No. 20)
Answer:

The cells in which chromosome number is double are known as diploid cells.
Male and female gametes unite together in the process of fertilization. Their chromosomes mix together in the zygote, therefore, the chromosome number is always diploid.
E.g. Diploid chromosome no. in human beings is 46. We hate 46 chromosomes in each of our body cells.

Question 6.
What do you mean by haploid (n) cell? (Text Book Page No. 20)
Answer:

The cells with only one set of chromosomes is known as haploid cell.
At the time of sexual reproduction, there is meiosis. In meiosis chromosome number of the parental germ cells are reduced to half. Therefore, gametes are haploid.
The haploid chromosome number (n) in human beings is 23.
Sperm and ovum both are haploid carrying 23 chromosomes each.

Question 7.
What do you mean by homologous chromosomes? (Text Book Page No. 20)
Answer:

Every species has definite number of chromosome pairs in their diploid cells.
In every pair, the two chromosomes are alike in shape, type and genes located over them.
Such chromosomes are called homologous chromosomes.
E.g. In human diploid cell, pair of chromosome no. 1 shows chromosome no. 1 from mother and chromosome no. 1 from father. These two chromosomes are homologous to each other.

Question 8.
Whether the gametes are diploid or haploid? Why? (Text Book Page No. 20)
Answer:
The cells that give rise to gametes are diploid (2n). But by meiosis they give rise to gametes which are haploid (n). Two haploid gametes undergo fertilization and the zygote formed becomes once again diploid (2n).

Question 9.
How are the haploid cells formed? (Text Book Page No. 20)
Answer:
Diploid cells undergo meiosis, which is a reduction division. In this way haploid cells are formed.

Question 10.
What is the importance of haploid cells? (Text Book Page No. 20)
Answer:

The gametes that take part in the sexual reproduction should be haploid.
Otherwise the chromosome number will not be maintained at constancy. E.g. Parents have 2n = 46 chromosomes in their cells.
If meiosis does not take place in them, the gametes formed will also contain 46 chromosomes.
The resultant offspring will have 46 + 46 = 92 chromosomes.
Such skewed number will produce large scale abnormalities.
But due to meiosis, the gametes formed are haploid and thus the chromosome number is maintained constant for every species. Gametes are haploid cells, this is the most important fact.

Internet is my friend. (Text Book Page No. 17)

Collect information.
(a) What are symptoms of diseases like night blindness, rickets, beriberi, neuritis, pellagra, anaemia, scurvy?
Answer:

Disease	Symptoms
Night blindness	Near sightedness, or blurred vision when looking at faraway objects Cataracts, or clouding of the eye’s lens. Inability to see in dark. Sometimes blindness.
Rickets	Weak and soft bones Stunted growth In severe cases, skeletal deformities.
Beriberi	Decreased muscle function, particularly in the lower legs. Tingling or loss of feeling in the feet and hands. Pain Mental confusion, difficulty in speaking Vomiting Involuntary eye movement, paralysis.
Neuritis	Numbness in hands and feet Tingling sensation, sharp, jabbing, throbbing, freezing or burning pain. Extreme sensitivity to touch. Lack of coordination and falling.
Pellagra	Delusions or mental confusion. Diarrhoea and nausea Inflammed mucous membrane. Scaly skin sores.
Anaemia	Fatigue and loss of energy Unusually rapid heartbeat, particularly with exercise Shortness of breath and headache, particularly with exercise Difficulty in concentrating Dizziness, Pale skin Leg cramps, Insomnia
Scurvy	Anaemia, debility, exhaustion, Spontaneous bleeding Pain in the limbs, and especially the legs, swelling in some parts of the body Ulceration of the gums and loss of teeth.

(b) What do you mean by coenzymes?
Answer:
Co-enzyme is a non-protein compound that is necessary for the functioning of an enzyme. It is bound to the enzyme as a catalyst. This increases the rate of reaction. Co-enzymes always act along the enzymes. They cannot work independently. But the same molecule of coenzyme can be used again and again.

Many co-enzymes are vitamins or derived from vitamins. When vitamin intake is too low, then an organism also lacks the co-enzymes that catalyse reactions. Water-soluble vitamins, which include all B complex vitamins and vitamin C, lead to the production of co-enzymes. Two of the most important and widespread vitamin-derived coenzymes are Nicotinamide Adenine Dinucleotide (NAD) and co-enzyme A.

FAD	Flavin Adenine Dinucleotide
FMN	Flavin Mono Nucleotide
NAD	Nicotinamide Adenine Dinucleotide
NADP	Nicotinamide Adenine Dinucleotide Phosphate

(d) How much quantity of each vitamin is required every day?
Answer:

Vitamin	Daily requirement
A	700 and 900 μ grams
B Complex	100 mg/day for adults.
C	75 mg
D	5 μg
E	10 mg
K	80 μg

Choose the correct alternative and write its alphabet against the sub-question number:

Question 1.
The process of glycolysis occurs in ……….
(a) cytoplasm
(b) mitochondria
(c) nucleus
(d) cell membrane
Answer:
The process of glycolysis occurs in cytoplasm.

Question 2.
ATP is called ………. of the cell.
(a) energy currency
(b) combustion fuel
(c) storage of glucose
(d) protein depot
Answer:
ATP is called protein depot of the cell.

Question 3.
Excess of carbohydrates are stored in liver and muscles in the form of ………….
(a) sugar
(b) glucose
(c) glycogen
(d) protein
Answer:
Excess of carbohydrates are stored in liver and muscles in the form of glycogen.

Question 4.
Chemically vitamin B₂ is ………….
(a) Riboflavin
(b) Nicotinamide
(c) Cyanacobalomine
(d) Pantothetic acid
Answer:
Chemically vitamin B₂ is Riboflavin

Question 5.
Somatic and stem cells undergo type of ………… division. (March 2019)
(a) meiosis
(b) mitosis
(c) budding
(d) cloning
Answer:
Somatic and stem cells undergo type of mitosis division.

Question 6.
We get ……….. energy from carbohydrates.
(a) 9 kcal/gm
(b) 9 cal/gm
(c) 4 cal/gm
(d) 4 kcal/gm
Answer:
We get 4 cal/gm energy from carbohydrates.

Question 7.
Which of the following vitamins is necessary for synthesis of NADH₂?
(a) Vitamin B₂
(b) Vitamin B₃
(c) Vitamin
(d) Vitamin K
Answer:
(b) Vitamin B₃

Write whether the following statements are true or false:

Question 1.
Glucose is oxidized step by step in the cells during the process of respiration at the body level.
Answer:
False. (Glucose is oxidized step by step in the cells during the process of cellular respiration.)

Question 2.
In aerobic respiration, glucose is oxidized in three steps.
Answer:
True

Question 3.
Glycolysis is also called Embden-Meyerhof-Paarnas pathway.
Answer:
True

Question 4.
Molecules of pyruvic acid formed in this glycolysis are converted into molecules of acetyl-co-enzyme A.
Answer:
True

Question 5.
Excess of ATP molecules obtained from proteins are not stored in the body.
Answer:
False. (Excess of ammo acids obtained from proteins are not stored in the body.)

Question 6.
Proteins of animal origin are called ‘first class’ proteins.
Answer:
True

Question 7.
The disease related with the deficient synthesis of insulin is heart disease.
Answer:
False. (The disease related with the deficient synthesis of insulin is diabetes.)

Match the columns:

Protein	Part of the body (July 2019)
(1) Haemoglobin	(a) muscles
(2) Ossein	(b) skin
	(c) bones
	(d) blood

Answer:
(1) Haemoglobin – blood
(2) Ossein – bones.

Protein	Part of the body
(1) Keratin	(a) muscles
(2) Myosin	(b) skin
	(c) bones
	(d) blood

Answer:
(1) Keratin – skin
(2) Myosin – muscles.

Find the odd one out:

Question 1.
Progesterone, Estrogen, Testosterone, Insulin
Answer:
Insulin. (All the others are hormones produced with the help of fatty acids.)

Question 2.
Actin, Ossein, Myosin, Melanin
Answer:
Melanin. (All the others are proteins concerned with locomotion of the body.)

Question 3.
Lipids, Carbohydrates, Fatty acids, Proteins
Answer:
Fatty acids. (All the others are food constituents; fatty acid is soluble nutrient.)

Question 4.
Alcohol, Vinegar, Pyruvic acid, Lactic acid.
Answer:
Pyruvic acid. (All the others are chemical substances formed by the process of fermentation.)

Question 5.
Tricarboxylic acid cycle, Citric acid cycle, Krebs cycle, EMP pathway.
Answer:
EMP pathway. (All the other terms are synonymous to each other.)

Considering the relationship in the first pair, complete the second pair by using a word or group of words:

Question 1.
Process that occurs in the cytoplasm : Glycolysis :: Process that occurs in the mitochondria ………
Answer:
Krebs cycle

Question 2.
Skin : Keratin :: Blood : …………
Answer:
Haemoglobin

Question 3.
Energy obtained from protein : 4 kcal :: Energy obtained from fats / lipids : …………
Answer:
9 Kcal

Question 4.
Breakdown of glucose molecule : Glycolysis :: Formation of glucose from proteins : …………….
Answer:
Gluconeogenesis

Question 5.
Condensation of chromosomes : Prophase :: Formation of spindle fibres : …………
Answer:
Metaphase

Question 6.
Division of nucleus : Karyokinesis :: Division of cytoplasm :: ………..
Answer:
Cytokinesis.

Write definitions:

Question 1.
Gluconeogenesis.
Answer:
Gluconeogenesis: Formation of glucose through non-carbohydrate sources such a protein is called gluconeogenesis.

Question 2.
Fermentation.
Answer:
Fermentation: Conversion of pyruvic acid produced in the process of glycolysis into other organic acids or alcohol with the help of some enzymes is called fermentation.

Name the following:

Question 1.
Products formed after complete oxidation of acetyl part present in the molecule of acetyl-coenzyme-A.
Answer:
Molecules of CO₂, H₂O, NADH₂, FADH₂ and ATP.

Question 2.
Place where electron transfer chain reaction take place.
Answer:
Mitochondria present in the cytoplasm of the cell.

Question 3.
Two co-enzymes involved in cellular respiration.
Answer:
NAD → Nicotinamide Adenine Dinucleotide and FAD Flavin Adenine Dinucleotide.

Question 4.
Scientist who discovered the TCA cycle.
Answer:
Sir Hans Krebs.

Question 5.
Steps of anaerobic respiration.
Answer:
Glycolysis and fermentation.

Question 6.
Most abundantly found protein nature.
Answer:
An enzyme RUBISCO present in plant chloroplasts.

Give scientific reasons:

Question 1.
We feel exhausted after exercising.
Answer:

When we undertake constant exercises, there may be shortage of oxygen for the cells.
Therefore, our muscles and other tissues perform anaerobic respiration in such condition.
In this process, lactic acid is formed.
Molecules of ATP produced in oxidation of food are also much less.
Thus, there is less energy in the body and accumulation of lactic acid too. All this brings about a feeling of exhaustion.

Answer the following questions in detail:

Question 1.
Write the forms to which the following food materials are converted after digestion:
(a) Milk (b) Potato (c) Oil (d) Chapati.
Answer:
(a) Milk: Proteins (casein) are converted into amino acids. Lactose sugar is converted into glucose. Lipids are converted into fatty acids and glycerol.
(b) Potato: Carbohydrates (starch) are converted into glucose.
(c) Oil: Lipids are converted into fatty acids and glycerol.
(d) Chapati: Carbohydrates (starch) are converted into glucose.

Question 2.
On which two levels does respiration take place in living organisms?
Answer:

In organism respiration takes place at two levels, viz. Body level and Cellular level.
Respiration at body level: The exchange of respiratory gases such as oxygen and carbon dioxide between body and surrounding is called respiration at body level.
Cellular respiration: Oxidation of nutrients inside the cell with or without oxygen is called cellular respiration.

Question 3.
Answer the following questions: (July 2019)
(a) Write main types of vitamins.
Answer:
A, B, C, D, E and K are main types of vitamins.

(b) Name water soluble vitamins.
Answer:
Water soluble vitamins are B and C.

Question 4.
Answer the following questions:
(a) Why some living organisms have to perform anaerobic respiration?
Answer:
Some bacteria and lower organisms do not live in the presence of oxygen. In order to survive, they have to perform anaerobic respiration. Sometimes, muscle cells and erythrocytes also perform anaerobic respiration when there is lack of enough oxygen.

(b) Give two examples of such living organisms.
Answer:
Yeast and bacteria.

(c) What are the two steps of anaerobic respiration?
Answer:
Glycolysis and fermentation are the two steps of anaerobic respiration.

Question 5.
Which is the energy currency of the cell? Explain it in detail.
Answer:

ATP or Adenosine triphosphate is the ‘energy currency’ of the cell.
Chemical composition of ATP is as follows: it is a triphosphate molecule having adenosine ribonucleoside. The nitrogenous compound-adenine, pentose sugar-ribose and three phosphate groups are present in ATP.
In this energy-rich molecule the energy remains trapped in the bonds by which phosphate groups are attached to each other.
ATP molecules are stored in the cells. As per the need, energy is derived by breaking the phosphate bond of ATP.
During cellular respiration, the oxidation of glucose yields 38 molecules of ATP. Whenever required they are consumed to liberate energy.

Question 6.
How is energy obtained during starvation or hunger?
Answer:

Due to starvation or hunger, there is less supply of nutrients and energy to the body. In such condition, the stored carbohydrates in the body also deplete.
In such condition, fats and proteins present in the body are utilized.
Fats or lipids are converted into fatty acids and proteins are broken down to amino acids.
Fatty acids and amino acids both are converted to acetyl-coenzyme-A.
Acetyl-coenzyme-A can undergo series of cyclic reactions and oxidised to liberate energy in the form of ATP molecules.

Question 7.
Why glycolysis is also called EMP pathway?
Answer:
Process of glycolysis was discovered by Gustav Embden, Otto Meyerhof, and Jacob Pamas along with their colleagues. They performed experiments on muscles to understand glycolysis. Hence, in their honour, glycolysis is also edited Embden-Meyerhof-Parnas pathway or EMP pathway.

Question 8.
How are proteins obtained? What are the components of the proteins?
Answer:

Protein, is a macromolecule which is formed by amino acids.
When digestion of protein takes place, it forms different amino acids. These amino acids are transported to each cell by blood circulation.
By protein synthesis, these amino acids are again used to make different kinds of proteins which our body needs.
Animal proteins are said to be ‘first class proteins’ as they contain good quality amino acids.
4 Kcal/gm energy is obtained from the proteins.

Question 9.
Where and in which forms the amino acids formed after digestion of food are used in the body?
Answer:
(1) After digestion of proteins, amino acids are formed. These amino acids are used to synthesise proteins in different forms. e.g.

In blood-Haemoglobin and antibodies are formed.
In skin – Melanin and keratin are formed.
In bones – Ossein is formed.
In pancreas-Insulin and trypsin are synthesized.
Pituitary and all other glands produce hormones by utilising amino acids.
In muscles – Actin and myosin are formed.
In all the cells, plasma membrane is formed by proteins. All enzymes are also synthesised using the amino acids.

Question 10.
What are fatty acids? What are the different uses of fatty acids ?
Answer:
(1) The fatty acids are components of the lipids. When lipids are digested, it forms fatty acids and alcohol (glycerol).
(2) There are certain chemical bonds between fatty acids and alcohol.
(3) Fatty acids are very essential for the health.
(4) After digestion, fatty acids are absorbed into the blood and transported to the cells.
(5) Different types of cells produce their own substances from these fatty acids.
E.g. (a) Plasma membrane is produced from phospholipids.
(b) Hormones like testosterone, progesterone, estrogen, aldosterone are produced from fatty acids.
(c) The axonal coverings around the neurons are also made from fatty acids.

Give explanations for the following statements:

Question 1.
After complete oxidation of a glucose molecules, 38 number of ATP molecules are formed.
Answer:
I. Glycolysis: No. of ATP molecules formed = 4
No. of ATP molecules used = 2
II. Krebs cycle : No. of ATP molecules formed = 2
III. ETC Reaction :
NADH₂: 10 NAD₂ x 3 ATP = 30 ATP
FADH₂ : 2 FADH₂ x 2 ATP = 4 ATP
Total ATP molecules produced = (4+2+34)
= 40 ATP
ATP molecules used = 2 ATP
Therefore, total ATP molecules = 38 ATP

Question 2.
At the end of glycolysis, pyruvate molecules are obtained.
Answer:
The process of glycolysis takes place m the cytoplasm of the cell. One molecule of glucose is gradually oxidized step by step forming two molecules of each pyruvic acid, ATP, NADH₂ and water. Of these, pyruvate or pyruvic acid takes part in the further reactions.

Question 3.
Genetic recombination occurs in pachytene phase of prophase of meiosis-I.
Answer:
In prophase of meiosis I there are total 5 stages. Of these in pachytene the process of crossing over takes place between homologous chromosomes as chromosomes come near each other forming synapsis.

Question 4.
All chromosomes are arranged parallel to equatorial plane of cell in metaphase of mitosis.
Answer:
In mitosis, the metaphase is the stage when dividing chromosomes lie on the equatorial plane of the cell. They are later pulled by the spindle fibres to the opposite poles.

Question 5.
For formation of plasma membrane, phospholipid molecules are necessary.
Answer:
Upon the digestion of fats, fatty acids and glycerol are formed. The fatty acids can be converted into phospholipid which are essential molecules for development of plasma membrane.

Question 6.
Our muscle cells perform anaerobic type of respiration during exercise.
Answer:
When the proportion of oxygen is less, then the cells switch over to anaerobic respiration. When we are exercising there is increased demand of oxygen for muscle cells. If this is not fulfilled, they perform anaerobic respiration during exercise.

Question 7.
Excess of carbohydrates are stored in liver and muscles in the form of glycogen.
Answer:
The carbohydrates which are not used to produce energy cannot be stored in the body in the form of glucose. This glucose is therefore converted into complex compound called glycogen. Glycogen is stored in muscles and liver.

Complete the paragraph by choosing the appropriate words given in the brackets:

Question 1.
(gamete, crossing over, haploid, Meiosis-II, meiosis-I, diploid)
……….. is just like mitosis. In this stage, the two haploid daughter cells formed in ……… undergo division by separation of recombined sister chromatids and four ……….. daughter cells are formed. Process of …………… production and spore formation occurs by meiosis. In this type of cell division, four haploid (n) daughter cells are formed from one ……….. cell. During this cell division, ………… occurs between, the homologous chromosomes.
Answer:
Meiosis-II is just like mitosis. In this stage, the two haploid daughter cells formed in meiosis-I undergo division by separation of recombined sister chromatids and four haploid daughter cells are formed. Process of gamete production and spore formation occurs by meiosis. In this type of cell division, four haploid (n) daughter cells are formed from one diploid cell. During this cell division, crossing over occurs between the homologous chromosomes.

Question 2.
(external, inhalation, alveolar, breathing, respiration, exhalation)
Release of energy from the assimilated food is called …………. Inhalation and exhalation is called …….. When ……….. is done, air enters the lungs. The oxygen from this air enters the blood while carbon dioxide from the blood exits from the blood. Through exhalation, CO₂ is given out. This gaseous exchange occurs through ……….. membrane. This is called ………….. respiration. The RBCs carry oxygen to every cell.
Answer:
Release of energy from the assimilated food is called respiration. Inhalation and exhalation is called breathing. When inhalation is done, air enters the lungs. The oxygen from this air enters the blood while carbon dioxide from the blood exits from the blood. Through exhalation, CO₂ is given out. This gaseous exchange occurs through alveolar membrane. This is called external respiration. The RBCs carry oxygen to every cell.

Read the paragraph and answer the questions given below:

1. Dietary fibre — found mainly in fruits, vegetables, whole grains and legumes — is probably best known for its ability to prevent or relieve constipation. But foods containing fibre can provide other health benefits as well, such as helping to maintain a healthy weight and lowering your risk of diabetes, heart disease and some types of cancer. Dietary fibre, also known as roughage or bulk, includes the parts of plant foods your body can’t digest or absorb. Unlike other food components, such as fats, proteins or carbohydrates — which your body breaks down and absorbs — fibre isn’t digested by your body. Instead, it passes relatively intact through your stomach, small intestine and colon and out of your body.

Questions and Answers :

Question 1.
Which food items provide rich fibre content?
Answer:
Fruits, vegetables, whole grains and legumes give rich amount of dietary fibre.

Question 2.
Enlist the advantages of fibres in diet.
Answer:
Fibres help to relieve constipation and help in maintaining a healthy weight and lowering risk of diabetes, heart disease and some types of cancer.

Question 3.
Are fibres digested in the body?
Answer:
No, fibres are not digested in the body but are passed on without any alteration.

Question 4.
Which is the path through which fibres pass in the digestive tract?
Answer:
Fibres pass through stomach, small intestine and colon.

Question 5.
What is a roughage?
Answer:
Roughage is the fibre content of the food which consists of plant matter which cannot be digested by the human enzymes, hence form undigested bulk matter in the faeces.

2. The substances formed by specific chemical bond between fatty acids and alcohol are called lipids. Digestion of lipids consumed by us is nothing but their conversion into fatty acids and alcohol. Fatty acids are absorbed and distributed everywhere within the body. From those fatty acids, different cells produce various substances necessary to themselves. Ex. the molecules called phospholipids which are essential for producing plasma membrane are formed from fatty acids. Besides, fatty acids are used for producing hormones like progesterone, estrogen, testosterone, aldosterone, etc. and the covering around the axons of nerve cells. We get 9 Kcal of energy per gram of lipids. Excess of lipids are stored in adipose connective tissue in the body.

Questions and Answers:

Question 1.
Define lipids.
Answer:
Lipids are molecules formed of fatty acids and glycerol (alcohol) which have specific bonds between them.

Question 2.
What happens to fats that are eaten in excess?
Answer:
When excess of fats are eaten, they are stored in adipose connective tissue.

Question 3.
Which hormones regulating reproductive functions are produced from fatty acids?
Answer:
Progesterone, estrogen and testosterone are the reproductive hormones produced from fatty acids.

Question 4.
How is plasma membrane of the cells formed?
Answer:
The digested fats are absorbed in the form of fatty acids. These are converted back to phospholipids from which plasma membrane of cells is formed.

Question 5.
What happens to lipids when their digestion is completed? How much energy do they provide?
Answer:
After complete digestion of lipids they are converted to fatty acids and glycerol. 1 gm of lipid provides 9 kcal of energy.

Diagram based questions:

Question 1.
Draw a neat diagram of the structure of chromosome and label the parts:
(a) Centromere (b) p-arm (March 2019)
Answer:

Question 2.
Sketch and label the diagram to show ATP – the energy currency of the cell.
Answer:

Question 3.
Mitochondria and Krebs cycle:
Answer:

(a) Which co-enzymes are shown in the diagram?
Answer:
The co-enzymes NADH₂ and FADH₂ are shown in the above diagram.

(b) Which chemical reaction takes place in the mitochondria? Which molecules are produced in this reaction?
Answer:
The chemical reaction that takes place in the mitochondria is called Electronic Transport Chain reaction. The molecules of H₂O, carbon dioxide and energy in the form of ATP are produced in this reaction.

Question 4.
Observe the diagrams 2.8 and 2.9 given on the Textbook page no. 19 and answer the following questions.

(a) Which peculiarity do you observe in the figure of Metaphase-I of meiosis ?
Answer:
The chromosomes are seen lying on the equatorial plane in the metaphase-I of meiosis.

(b) What is the important difference between Telophase-I and Telophase-II of meiosis?
Answer:
In figure of Telophase-I the diploid chromosomes are seen in two daughter cells. In Telophase-II four daughter cells are seen with haploid chromosomes in them.

(c) Which figure shows phenomena of crossing over?
Answer:
The third figure of Prophase-I shows phenomena of crossing over.

Question 5.
Label the diagram below? Which phase of cell division is seen in the above diagram?
Answer:
The above figure shows Telophase-II of Meiosis-II.

Question 6.
Observe and label the diagram: (Text Book Page No. 13)
Answer:

Activity based questions:

Question 1.
Complete the following chart and state which process of energy production it represents: (March 2019)

Answer:
The chart shows process of energy production through aerobic respiration of carbohydrates, proteins and fats.
(Answers to the blanks in chart are given in bold.)

Project:

Project 1.
Use of ICT: (Text Book Page No. 20)
Collect videos and photographs of different life processes in living organisms. Prepare a presentation and present it on the occasion of science exhibition.

Project 2.
Books are my friend: (Text Book Page No. 20)
Read different Encyclopaedias of technical terms in biology and anatomy and other reference books.

10th Std Science Part 2 Questions And Answers:

Std 8 History Chapter 6 Questions And Answers Beginning of Freedom Movement Maharashtra Board

February 6, 2025January 5, 2025 by Bhagya

Balbharti Maharashtra State Board Class 8 History Solutions Chapter 6 Beginning of Freedom Movement Notes, Textbook Exercise Important Questions and Answers.

Class 8 History Chapter 6 Beginning of Freedom Movement Questions And Answers Maharashtra Board

Beginning of Freedom Movement Class 8 Questions And Answers Chapter 6 Maharashtra Board

Class 8 History Chapter 6 Beginning of Freedom Movement Textbook Questions and Answers

1. (A) Rewrite the statements by choosing the appropriate options:

Question 1.
The Servants of India Society was founded by
(a) Ganesh Vasudev Joshi
(b) Bhau Daji Lad
(c) M. G. Ranade
(d) Gopal Krishna Gokhale
Answer:
(d) Gopal Krishna Gokhale

Question 2.
The first session of Indian National Congress was held at
(a) Pune
(b) Mumbai
(c) Kolkata
(d) Lucknow
Answer:
(b) Mumbai

Question 3.
wrote Geeta Rahasya.
(a) Lokmanya Tilak
(b) Dadabhai Nowrojee
(c) Lala Lajpat Rai
(d) Bipinchandra Pal
Answer:
(a) Lokmanya Tilak

B. Write the Names :

Question 1.
Moderate leaders
(i) ……… (ii) ………
Answer:
(i) Gopal Krishna Gokhale
(ii) Ferozshah Mehta

Question 2.
Extremist leaders
(i) ……. (ii)………..
Answer:
(i) Lokmanya Tilak
(ii) Lala Lajpat Rai

2. Explain the following statements with reasons:

Question 1.
In the struggle for Independence, a sense of identity was awakened among the Indians.
Answer:

Western education familiarised the educated Indians with modern values such as liberty, equality, democracy and nationalism.
The Asiatic Society at Bengal edited and published hundreds of manuscripts in Sanskrit, Persian and other Indian languages.
The realization that India had a rich ancient heritage aroused the feeling of national pride. This gave a sense of identity to Indians.

Question 2.
Two groups were formed in the Congress.
Answer:
1. Though at a slow pace, the contribution of Indian National Congress was consistent in the initial stage. But the extremists felt to intensify the freedom struggle.
2. Moderates and Extremists were unanimous about the objectives of Congress. But they had differences regarding the methods/ways to achieve it.
3. The moderates insisted on constitutional measures whereas extremists wanted to adopt severe methods.
4. The tension between these groups increased during the Surat session in 1907.
This led to the formation of two groups within the Congress.

Question 3.
Lord Curzon decided to partition Bengal.
Answer:
1. Bengal was a large province. So under the pretext of administrative convenience, the province of Bengal was partitioned by Lord Curzon.
2. Accordingly, the Muslim-majority East Bengal and the Hindu-Majority West Bengal were created in 1905.
3. The real motive was to create a divide between the Hindus and the Muslims and thereby weaken the nationalist movement. The British used the Policy of ‘Divide and Rule’.

3. Write short notes:

Question 1.
Objectives of the Indian National Congress :
Answer:
The Indian National Congress was established in 1885 with the following objectives:

To bring together the people of India on a common platform.
To create a feeling of unity among them, irrespective of religion, race, language, geographical territories.
To provide opportunities to understand one another’s problems and views.
To increase the feeling of unity among the people.
To take measures for the upliftment of the country.

Question 2.
Anti Partition Movement :
Answer:

With the motive to create a divide between the Hindus and the Muslims, Lord Curzon divided the province of Bengal in the Muslim-majority East Bengal and the Hindu-majority West Bengal in 1905.
The day of partition, 16th October was observed as the ‘National Mourning Day’.
All over India, protest meetings were organised to condemn the decision of the government.
Singing of Vande Mataram and Raksha-bandhan programmes were arranged to mark the protest.
Government-run schools and colleges were boycotted in large number by the students.
Sensing the intensity and severity of dissatisfaction the British annulled the Partition of Bengal.

Question 3.
Four Point Programme of the Indian National Congress :
Answer:
In the session of 1906 of the Indian National Congress, the four-point programme was unanimously accepted.

Swadeshi: To make use of capital, resources, manpower in our country so that it becomes self-sufficient.
Boycott: It was decided to boycott foreign goods as a first step, and boycott of foreign rule be the next step. It would be an attack on the roots of British imperialism.
Swaraj: The final objective is to attain freedom.
National Education: To impart education which will create pride for the nation among people.

4. Explain the background behind the establishment of Indian National Congress with the help of following points:
1. Centralisation of administration
2. Economic exploitation
3. Western education
4. Study of Ancient Indian History
5. Role of newspapers
Answer:
The background behind the establishment of the Indian National Congress in 1885:

1. Centralisation of administration :

The uniform policies, identical reforms and equality before law brought the nation under one roof.
The network of roads and railways brought the people of India together.
It developed the feeling of unity among Indians.

2. Economic exploitation :

The economic exploitation of India through the imperialistic policies led to the drain of the Indian wealth to England.
Industries declined and the farmers became bankrupt.
Imposition of taxes on middle class and the exploitation of worker class by the capitalist led to growth of discontent.

3. Western education :

Western education familiarised the educated Indians with modern values and principles such as liberty, equality and democracy.
They accepted principles like rationalism, humanity and nationalism.
They realised that they can carry out work of the country by following them.

4. Study of Ancient Indian History :

The manuscripts in Sanskrit, Persian and many other languages were examined and research was published.
Many western Scholars started to study Indian culture.
The realisation that India had a rich ancient heritage aroused the feeling of national pride among Indians.

5. Role of newspapers :

Newspapers in English and vernacular languages carried articles criticising the policies of the government.
It led to social and political awakening.

Do you Know?

Maharashtra Board Class 8 History Solutions Chapter 6 Beginning of Freedom Movement 1

Project:

Collect additional information about the leaders of the early phase of Indian National Congress with the help of the internet.

Class 8 History Chapter 6 Beginning of Freedom Movement Additional Important Questions and Answers

Rewrite the statements by choosing the appropriate options:

Question 1.
…………. newspaper was a mouthpiece of extremist ideology in Bengal.
(a) Dnyanoday
(b) Dnyanprakash
(c) Amrit Bazar Patrika
(d) Kesari
Answer:
(c) Amrit Bazar Patrika

Question 2.
………….. declared to give responsible political system to India.
(a) Montague
(b) Morley
(c) Dalhousie
(d) Chelmsford
Answer:
(a) Montague

Question 3.
A committee under the leadership of met …………… Governor-General Lord Minto.
(a) Sir Sayyad Ahmad Khan
(b) Abdul Latif
(c) Baddrudin Tayyabji
(d) Aga Khan
Answer:
(d) Aga Khan

Question 4.
The Home Rule Movement was launched in …………. against Colonialism.
(a) South Africa
(b) Ireland
(c) Scotland
(d) Switzerland
Answer:
(b) Ireland

Question 5.
…………… was established in 1906.
(a) The Indian National Congress
(b) Moderate Party
(c) Extremist Party
(d) The Muslim League
Answer:
(d) The Muslim League

Identify the wrong pair and correct it:

(1) The first President of Indian National Congress
– Wyomesh Chandra Banerjee
(2) Assassinated Rand
– The Chapekhar Brothers
(3) He pronounced the word Swaraj for the first time
– Lokmanya Tilak
(4) The British officer who took initiative in forming the Indian National Congress.
– Allen Octavian Hume
Answer:
Wrong Pair: He pronounced the word Swaraj for the first time.
– Lokmanya Tilak
Corrected pair: He pronounced the word Swaraj for the first time
– Dadabhai Nowrojee.

Write the Names:

Question 1.
They studied ancient Indian culture
(i) ……… (ii) …….
Answer:
(i) Dr. Bhau Daji Lad
(ii) Dr. R.G. Bhandarkar

Question 2.
Leaders of Home Rule Movement
(i)……… (ii) ……
Answer:
(i) Dr. Annie Besant
(ii) Lokmanya Tilak.

Answer the following questions in one sentence each:

Question 1.
Which institute was established to study ancient Indian culture?
Answer:
The Asiatic Society was established in Bengal to study ancient Indian culture.

Question 2.
Which were the mediums initially used by the extremist leaders to create political awakening?
Answer:
The extremist leaders initially used the mediums of newspapers, national education and national festivals.

Question 3.
What was the objective of the extremist leaders in founding the educational institutions?
Answer:
The extremist leaders established educational institutions for creating a generation which will have concern for their own language and tradition.

Question 4.
Who led the Anti Partition Movement?
Answer:
Surendranath Banerjee, Anand Mohan Bose, Rabindranath Tagore and such other leaders led the Anti-Partition Movement.

Question 5.
How did Tilak criticise the Montague-Chelmsford Act?
Answer:
Lokmanya Tilak criticised the Moptague-Chelmsford Act in the following words, “This is neither Swaraj nor its foundation.”

Question 6.
What did Lokmanya Tilak firmly state?
Answer: Lokmanya firmly stated that “Swaraj is my birthright and I shall have it.”

Complete the graphical presentation:

Question 1.
Maharashtra Board Class 8 History Solutions Chapter 6 Beginning of Freedom Movement 2
Answer:

Question 2.
Maharashtra Board Class 8 History Solutions Chapter 6 Beginning of Freedom Movement 4
Answer:

Answer:

Question 3.
Maharashtra Board Class 8 History Solutions Chapter 6 Beginning of Freedom Movement 6
Answer:

Explain the Concept :

Question 1.
Moderates :
Answer:

The Moderates were the leaders who wanted to carry out nationalistic movement within the constitutional methods and peaceful meAnswer:
The leaders were realistic and highly educated and had faith in the justice of the British.
They had hope that if they place their demands in constitutional manner the British will give justice to their demands.
They were aware that a strong foundation needs to be built through organised work.
The philosophy and principles of western thinkers like liberalism, freedom, equality, fraternity influenced them.

Question 2.
Extremists :
Answer:

The leaders of the Indian National Congress who advocated intensification of the struggle to attain freedom were known as Extremists.
Moderates and Extremists were unanimous about the objectives of Congress. The Extremists had no faith in the constitutional methods of the Moderates.
According to Extremists, freedom will be attained only if lakhs of people participated in the freedom movement and challenge the British government.

Write short notes :

Question 1.
First session of Indian National Congress :
Answer:

The founding session of the Indian National Congress took place on 28th December, 1885 at Gokuldas Tejpal Sanskrit school in Mumbai.
It was presided by Wyomesh Chandra Banerjee, a renowned lawyer from Kolkata.
It was attended by seventy-two delegates from different provinces of India.
Allen Oct avian Hume took the initiative in establishing of the Indian National Congress.
Increase in the number of Indians in the administration, reduction in military expenditure were the demands placed before the British government.

Question 2.
Servants of India Society :
Answer:
1. Gopal Krishna Gokhale founded the Servants of India Society in 1905.
2. Its main objectives were :

to create love for the county.
teach them sacrifice of self-interest.
no differentiation on the basis of caste and religion.
to create social harmony.
to spread education.

Question 3.
The Lucknow Pact :
Answer:

An attempt was made under the leadership of Lokmanya Tilak to resolve differences in the Indian National Congress at its Lucknow session in 1916.
In the same year, there was an agreement between Indian National Congress and the Muslim League, known as the Lucknow Pact.
According to this Pact, Indian National Congress agreed to separate electorate for Muslims.
In return, the Muslim League agreed to support the Indian National Congress in its work for getting political rights to India.

Question 4.
Home Rule Movement :
Answer:

Home rule means self-rule or self-government.
It was modelled after the Home Rule Movement in Ireland.
It was led by Dr. Annie Besant and Lokmanya Tilak.
They made extensive tours in different parts of the country so that the demand of self-government could reach the common people.

Explain the following statements with reasons:

Question 1.
A feeling of nationalism developed among the IndiAnswer:
Answer:

The British established a centralised administration in India and applied uniform policies all over the country.
They also laid down the principle of equality before law.
They introduced the modern means of transport and communication.
It benefited Indians as well. This made possible for the people living in different parts of India to establish contact with one another. This factors developed a feeling of nationalism among the Indians.

Question 2.
Lokmanya was imprisoned in 1897.
Answer:

In 1897, hundreds of people died in Pune due to the epidemic of Plague.
An officer name Rand was appointed to bring the epidemic under control.
He started a search campaign to find Plague patients and adopted oppressive measures.
To avenge this cruel and oppressive treatment meted out to people, the Chapekar brothers assassinated him.
An unsuccessful attempt was made by the government to connect Lokmanya Tilak with this conspiracy.
When they failed in their attempt, they imprisoned him with revenge.

Question 3.
The National Congress split at its Surat session in 1907.
Answer:

The differences between the moderates and the extremists reached a climax in 1907.
The moderates wanted to keep aside the resolution of Swadeshi and Boycott which was thwarted by the extremists.
Some moderate leaders blamed the extremist leaders for trying to capture the Indian National Congress.
It became impossible to arrive at a compromise between both the groups. As a result the Indian National Congress split at its Surat session in 1907.

Question 4.
The charge of sedition was put on Lokmanya Tilak.
Answer:

There was wide protest against the partition of Bengal throughout the country.
With a view to restrain the anti¬partition movements government resorted to many suppressive measures.
Strict action was taken against extremists leaders which caused severe reactions in Bengal.
The revolutionaries adopted means of firing and bomb blasts which was advocated by Lokmanya Tilak through his newspaper Kesari.

Therefore, the charge of sedition was put on Lokmanya Tilak by the British government for which he was sent to Mandalay jail for 6 years.

Question 5.
The government passed the Morley- Minto Act.
Answer:
1. The economic policies of the British increased poverty in India.
2. It created dissatisfaction in the minds of the people against British rule.
3. The oppressive measures adopted by Lord Curzon to suppress the protest of partition of Bengal, exclusion of educated Indians in government services and the unjust treatment towards Indians in Africa all this added to the dissatisfaction among the IndiAnswer:
4. Morley-Minto reforms were passed by the British government as a temporary remedy to calm discontent among the IndiAnswer:

Question 6.
The Montague-Chelmsford Act disappointed the people of India.
Answer:
The Montague-Chelmsford Act disappointed the people of India, because

The British Government had declared its intention to gradually grant the right to self-rule and responsible government in 1917.
In 1919, the British Parliament passed an act to bring constitutional reforms in India.
According to the Act, less important departments were transferred to Indian ministers and important departments like Finance, Home affairs and Revenue was kept with the Governor.
Thus, it belied the hope that the Act would lay foundation of responsible government in India and disappointed the people.

Answer the following questions in 25-30 words:

Question 1.
What realisation led to the emergence of a political organisation on all India level?
Answer:

English educated Indians were instrumental to bring about Renaissance.
They launched reform movements in social, political, religious, economic and cultural field in different parts of the country.
The political organisations in different parts of the country formed during various movements felt the need to create a political organisation on an all India level having common goal.
It was necessary to bring together groups and people who had political awareness.
It was necessary to draw attention of the people towards questions of the nation. This led to the emergence of a political organization on all India level.

Question 2.
State the impact of imperialistic policy of the British on India.
Answer:

The economic exploitation of India through the imperialistic policies led to the drain of the Indian wealth to England.
The compulsion to grow cash crops, burden of land taxes and recurring famines made conditions of farmers miserable. All these broke the backbone of the Indian agriculture.
With the decline of traditional industries, there was increase in unemployment.
The workers were exploited by the capitalists.
The middle class suffered due to imposition of various new taxes.
This was the impact of the British imperialist policy which led to discontent among the IndiAnswer:

Question 3.
State the impact of western education?
Answer:

Due to spread of western education, new ideas like Justice, Liberty, Equality, Democracy, etc. were introduced to the IndiAnswer:
The young Indians imbibed the values like rationalism, humanity, nationalism and scientific attitude.
They developed a feeling that they could carry out the work of the country.
English became the new medium of communication.

Question 4.
What message did Dadabhai Nowrojee give at the session of Congress in 1906?
Answer:
At the session of the Indian National Congress in 1906, Dadabhai Nowrojee pronounced the word ‘Swaraj’ for the first time. He gave the message

to remain united.
try sincerely and fulfill the aim of Swaraj so that those who are poor, hungry and having diseases could be saved,
India to get respectable position among the developed countries.

Question 5.
Write about the process of formation of Muslim League.
Answer:

The British got very disturbed by the overwhelming public response to the Indian National Congress in the anti-partition movement.
They once again resorted to the policy of ‘Divide and rule’.
Many British officers suggested that a separate political organisation was necessary to safeguard the interests of the Muslims.
Due to motivation of British government, under the leadership of Aga Khan a committee of upper-class Muslims met Governor-General Lord Minto.
Thus, encouraged by Lord Minto and other British officers, the Muslim League was formed in 1906.

Question 6.
What were the provisions of Morley- Minto Act?
Answer:
1. The Morley-Minto Act of 1909 provided for increase of the number of Indian members in the legislatures and the inclusion of some elected Indian members.
2. It created separate electorates for the Indian Muslims.

Question 7.
What is Responsive Cooperation?
Answer:
1. India had to face the brunt of First World War which led to growing dissatisfaction among people.
2. To curb their dissatisfaction and get cooperation, Montague, the Secretary of State for India, declared in 1917 that Britain would gradually grant the right to self-rule and a responsible government to India. ,
3. Lokmanya Tilak declared that if the British Government showed sympathy and a considerate attitude to the demands of the people then the people of India would cooperate with the government. This is called ‘Responsive Cooperation’.

Write answer in details :

Question 1.
Give a brief account of the work of Extremist leaders in India’s freedom struggle.
Answer:

Extremist leaders Lokmanya Tilak, Bipin Chandra Pal, Lala Lajpat Rai advocated intensification of the struggle since the British did not respond to the petitions and appeals.
) Initially, they used the mediums of newspapers, national festivals and national education to bring about political awakening.
They formed educational institutions to sow the seeds of nationalism in society and to create a generation which will show concern about their language and tradition.
Lokmanya Tilak severely criticised the suppressive policies or the British through the newspapers like ‘Kesari’ and ‘Maratha’.
Lokmanya Tilak started Ganesh Utsav and Shiv Jayanti to bring people together.
The leaders did not adopt the means of armed revolution but insisted on extensive agitations.
Swaraj, Swadeshi, National Education and Boycott was the four-point ‘ programme accepted.
The Moderates laid the foundation of freedom struggle and the Extremists carried it forward.

Question 3.
Which measures were taken by the : British government to suppress the Anti-Partition Movement?
Answer:
The British government adopted following measures to suppress the anti-partition movement:

The public meetings were banned.
Strict punishment was given to those who broke the law.
Even school children were beaten up.
Many restrictions were imposed on the newspapers.
The British confiscated many printing/presses on false ground of criticising the ; government.
Writers and editors were imprisoned.
Strict actions were taken against many extremist leaders.
Lokmanya Tilak was sent to Mandalay jail at Myanmar for 6 years on the charge of sedition.
Bipin Chandra Pal was sent to jail and Lala Lajpat Rai was deported out of Punjab.

Identify the picture and write about his contribution to the freedom struggle.
Maharashtra Board Class 8 History Solutions Chapter 6 Beginning of Freedom Movement 8
Answer:

The Above picture is of Lokmanya Tilak.
He started the newspapers Kesari and Maratha.
He started festivals like Ganesh Utsav and Shiv Jayanti for people to come together and get inspiration from contribution of national personalities.
The bomb attacks by the revolutionary was advocated through newspaper Kesari and Maratha.
Due to this, he was charged with sedition and put in Mandalay jail for 6 years.
When he was in Mandalay prison he wrote Geetarahasya which advocated philosophy of Karmayoga and stressed upon the people to always remain in action.
An attempt was made under his leadership to resolve differences between two groups in the Indian National Congress in its session of 1916.
He started the Home Rule Movement along with Dr. Annie Besant.
He travelled in different parts of India so that the demand for self government reach the common man.
He firmly declared, ‘Swaraj is my birth right and I shall have it.’
He criticised the Montague Chelmsford Reform Act when it failed to fulfill the demand of responsible government.

Question 4.
Do you feel the four-fold programme implemented by Indian National Congress needs to be implemented even today? Why?
Answer:
In the pre-independence period, Indian National Congress implemented the four-fold programme of Swaraj, Swadeshi, Boycott and National education. The programme needs to be implemented today but with slight changes.

1. Swaraj: Today we have political freedom but we lack good Governance. Common man, farmer, women and the backward classes still suffer.

2. Swadeshi: In the world of Globalisation, goods from other countries have entered Indian markets. It is necessary for the Indian industries to implement programme of Swadeshi to sustain.

3. Boycott: It is not possible to boycott foreign goods but we should insist on indigenous goods wherever possible.

4. National education: Schools in India impart education catering to different needs and ideologies but they fall short to create national pride and imparting character training.

8th Std History Questions And Answers:

Heredity and Evolution Class 10 Questions And Answers Maharashtra Board

January 6, 2025January 5, 2025 by Bhagya

Balbharti Maharashtra State Board Class 10 Science Solutions Part 2 Chapter 1 Heredity and Evolution Notes, Textbook Exercise Important Questions and Answers.

Std 10 Science Part 2 Chapter 1 Heredity and Evolution Question Answer Maharashtra Board

Class 10 Science Part 2 Chapter 1 Heredity and Evolution Question Answer Maharashtra Board

Question 1.
Complete the following diagram.

Answer:

Question 2.
Read the following statements and justify same in your own words with the help of suituble examples.
a. Human evolution began approximately 7 crore years ago.
Answer:

Approximately around 7 crore years back the ice age began on the earth. In such conditions, dinosaurs became extinct. The evolution and diversity of mammals started during this time. Due to change in climate the forest cover also declined rapidly.
Ancestors of monkey-like animals were Lemur like animals which evolved during this time period.
The tails of these monkey-like creatures started vanishing very gradually around 4 crore years ago.
The body and brain both increased in volume forming first ape like animals. The monkey like ancestors gave rise to two evolutionary links to apes and human like animals.
Later, the human evolution took place by changes in the brain volume, the ability to walk upright, excessive use of hand for manipulations.
This journey of human evolution began 7 crore years ago. But the true wise and intelligent man arose around 50,000 years ago.

b. Geographical and reproductive isolation of organisms gradually leads to speciation.
Answer:

Every species survives in specific geographical conditions. The requirements of food and habitat, is specific for each species. Their reproductive ability and period is also different.
Therefore, the individuals from one species cannot reproduce with individuals from other species.
When they are separated by a distance or geographical barriers they are said to be isolated geographically.
When they cannot reproduce with each other, they are said to be isolated reproductively.
The ancestor species of both these subspecies may be the same but due to isolation over a very long-time duration, there is genetic variation between the two. Therefore, the isolation leads to speciation.

c. Study of fossils is an important aspect of study of evolution.
Answer:
Answer:

Fossils offer palaeontological evidence for the evolutionary process.
Due to some natural calamities the organisms get buried during ancient times.
The impressions and remnants of such organisms remain preserved underground. The hot lava also traps some organisms or their impressions. All such formations form fossils.
Study of fossils help the researcher to understand the characteristics of the organisms that existed in the past.
Carbon dating method also helps in finding out exact age of the fossil. According to the structure of earth’s crust the fossils are obtained at specific depths.
The oldest ones are obtained at the depth while the relatively recent ones occupy the upper surface. Thus fossils of invertebrates were seen in very old Palaeozoic era. Later were seen fossils of Pisces, Amphibia and Reptilia. The Mesozoic era was dominated by reptiles while Coenozoic era showed presence of mammals.
In this way, study of fossils unfold the evolutionary secrets.

d. There is evidences of fatal Science among chordates.
[Please read the above question as: Among different chordates there are embryological evidences.]
Answer:

Very young embryos of fish, amphibians, reptiles, birds and mammals show quite similar structure in the early stages.
As the further growth takes place, they acquire different patterns.
The initial similarity between the vertebrate embryos is an evidence that during evolution, there was a common ancestor for all the vertebrate classes.
This is called embryological evidence for vertebrate evolution.

Question 3.
complete the statements by choosing correct options from bracket.
(Genes, Mutation, Translocation, Transcription, Gradual development, Appendix)
a. The causality behind the sudden changes was understood due to ………… principle of Hugo de Vries.
Answer:
Mutation

b. The proof for the fact that protein synthesis occurs through ……….. was given by George Beadle and Edward Tatum.
Answer:
Genes

c. Transfer of information from molecule of DNA to mRNA is called as …………… process.
Answer:
Transcription

d. Evolution means ………….
Answer:
Gradual development

e. Vestigial organ ……….. present in human body is proof of evolution.
Answer:
Appendix

Question 4.
Write short notes based upon the information known to you.
a. Lamarckism.
Answer:
(1) Lamarckism consists of two theories which were proposed by Jean Baptiste Lamarck. These are as follows: (a) Use and disuse of the organs (b) Inheritance of acquired characters.
(2) In theory of use and disuse of organs, Lamarck says : The characters of organs develop because specific activities that the organisms perform. If such organ is not used it gets degenerated. Thus the morphological changes take place due to activities or inactivity of a particular organism.
(3) To emphasise this theory, he quoted following examples. Due to constant extension of neck to eat foliage from the top of the trees, giraffe’s neck became long. Similarly blacksmith has strong arms due to constant work. Flightless ostrich and emu did not fly and hence their wings became useless. Aquatic birds like swan and duck made their feet suitable for swimming by living in water. Snake lost limbs as it tried burrowing mode.
(4) Such acquired characters are passed from one parental generation to the offspring. This is called inheritance of acquired characters.
(5) The theory of inheritance of acquired characters is not accepted as such transmission of acquired character does not take place. Only genetic characters are transmitted.

b. Darwin’s theory of natural selection.
Answer:

Charles Darwin proposed the theory of natural selection after making many observations on different specimens. He published a concept ‘Survival of the fittest’.
Darwin explains this concept as follows: All the organisms reproduce prolifically. Therefore, there is always a competition for food, mate, etc. Only adaptations for sustaining this struggle.
Natural selection plays important role by selecting only those organisms which are fit to live. Those that do not have better adaptations, perish. Selected sustaining organisms then perform reproduction and form new species in a very long period of time.
Darwin published his views in the book titled ‘Origin of Species’.

c. Embryology.
Answer:

Embryology is the study of developing embryos.
These embryos in their initial stages are very similar to each other.
These similarities decrease later in the development.
This similarity in initial stages indicate that these vertebrates have originated from a common ancestor.
In evolutionary science, comparative study of embryos of various vertebrates provide evidence for evolution.

d. Evolution.
Answer:

The sequential changes in the groups of living organisms that take place very gradually is called evolution.
Evolution is also described as the formation of new species due to natural selection.
The process of evolution takes millions of years for development and speciation of different organisms.
Changes in stars and planets in space and the changes in biosphere occurring on the Earth are all included under study of evolution.
Due to evolution organisms become fit, biodiversity is increased, and new species are created.
Different scientists have put forth theories to explain the process of evolution. Among these Charles Darwin’s theory of natural selection and speciation is accepted worldwide.

e. Connecting link.
Answer:
Some living organisms possess some characters in them which are the distinctive features of different groups or phyla. Such individuals connect these two groups by sharing the characters of both and hence they are known as connective links.

Examples: (1) Peripatus: Peripatus is the connecting link between Annelida and Arthropoda. It shows characters of both animal phyla. Like annelid worm, it shows segmented body, thin cuticle and parapodia. Like an arthropod, it shows open circulatory system and tracheal system for respiration.
(2) Duck Billed platypus: This is a connecting link between reptiles and mammals. Like reptiles it lays eggs but like mammals it has mammary glands and hairy skin.
(3) Lung fish: Lung fish is a connecting link between fishes and amphibians. Though a fish, it shows lungs for respiration as in amphibian animals.
(4) Connecting links indicate the direction and hierarchy of evolution.

Question 5.
Define heredity. Explain the mechanism of hereditary changes.
Answer:
(1) Heredity: Heredity is the process by which the biological characters from parental generation are transmitted to the next generation through genes.

(2) The mechanism of hereditary changes:

Mutation: Sudden change in the parental DNA can cause mutations. This results into changes in the hereditary characters.
At the time of meiosis, the crossing over takes place. This creates new recombination of the genetic information. Therefore, the haploid gametes produced carry changed hereditary characters.

Question 6.
Define vestigial organs. Write names of some vestigial organs in human body and write the names of those animals in whom same organs are functional.
Answer:

Vestigial organs are degenerated or underdeveloped organs of organisms which do not perform any function.
According to the principle of natural selection, such organs are on the verge of disappearance. But it takes many millions of years for its complete vanishing.
The vestigial organs in one animal may be of use but to other kind of the animal as they still perform regular functions.
Appendix is vestigial for humans, it does not perform any function but in ruminant animals it is concerned with digestion.
Ear muscles are vestigial for us but in monkeys and cattle they are functional.
Names of vestigial organs in human body-Appendix, tail-bone or coccyx, wisdom teeth and body hair.

Question 7.
Answer the following questions.
a. How are the hereditary changes responsible for evolution?
Answer:
Hereditary characters are transmitted from parental generation to the offspring. These characters are maintained through inheritance. But the genes which are beneficial for the organisms in helping them to adapt to the environment are transmitted to the next generations in a greater proportion. This happens due to natural selection.

The process of evolution happens at a very slow pace. The favourable genes are preserved in the species as they bring about better survival of the individuals. Such individual reproduces more efficiently and evolve. The individuals with unfavourable genes are not selected by nature and are thus removed from the population through natural death. The fuel for evolution is thus truly supplied by the hereditary changes.

b. Explain the process of formation of complex proteins.
Answer:
The proteins are synthesised in following steps, viz. transcription, translation and translocation. Protein synthesis takes place according to the sequence of nucleotides present on the DNA molecule with the help of RNA molecules. This is known as central dogma of protein synthesis.

1. Transcription: In the process of transcription, mRNA is produced as per the nucleotide sequence on the DNA. For this the two strands DNA are separated. Only one strand participates in the formation of mRNA. The sequence of nucleotides which is complementary to that of present on DNA is copied on mRNA. Instead of thymine present in DNA, uracil is added on the mRNA. Transcription takes place in nucleus but the mRNA leaves nucleus, carries the genetic code and enters the cytoplasm. This genetic code is always in triplet form arid hence is known as triplet codon. The code for each amino acid always consists of three nucleotides.

2. Translation: Each mRNA may carry thousands of codons. But each codon is specific for only one amino acid. The tRNA molecule brings the required amino acid as per the code present on mRNA. There is anticodon on each tRNA which is complementary to the codon on mRNA. This process is known as translation.

3. Translocation: In translocation, the ribosome keeps on moving from one end of mRNA molecule to other end by distance of one triplet codon. While this process is taking place, rRNA, helps in joining the amino acids together by peptide bonds. The peptide chains later come together to form complex protein molecules.

c. Explain the theory of evolution and mention the proof supporting it.
Answer:
1. Theory of evolution:

According to the theory of evolution, first living material was in the form of protoplasm which was formed in ocean.
Gradually, it gave rise to unicellular organisms. Changes took place in these unicellular organisms which made them evolve into larger and more complex organisms.
All evolutionary changes were very slow and gradual taking about 300 crore years to happen.
Different types of organisms were developed as the changes and development that occurred in living organisms wefts all round and multi-dimensional.
Hence, this overall process of evolution is called organizational and progressive.
Variety of plants and animals developed from the ancestors having different structural and functional organization during the process of evolution.

2. Proof here means evidences of evolution.
These evidences are as follows:

Morphological evidences
Anatomical evidences
Vestigial organs
Palaentological evidences
Connecting links
Embryological evidences.

d. Explain with suitable examples importance of anatomical evidences in evolution. (July 2019)
Answer:

There are similarities in the structure and anatomy of different animal groups. E.g. human hand, forelimb of bull, patagium of bat and flipper of whale are all similar in their internal anatomy. There is similarity in the bones and joints of all these specimens.
External morphology does not show any similarity. Use of each of the organ is also different in different animals. Structurally, they may not be related.
However, the similarities in the anatomy is an evidence that they may have a common ancestor.
In this way, the anatomical evidence throws light on the process of evolution.

e. Define fossil. Explain importance of fossils as proof of evolution.
Answer:

Fossils offer palaeontological evidence for the evolutionary process.
Due to some natural calamities the organisms get buried during ancient times.
The impressions and remnants of such organisms remain preserved underground. The hot lava also traps some organisms or their impressions. All such formations form fossils.
Study of fossils help the researcher to understand the characteristics of the organisms that existed in the.past.
Carbon dating method also helps in finding out exact age of the fossil. According to the structure of earth’s crust the fossils are obtained at specific depths.
The oldest ones are obtained at the depth while the relatively recent ones occupy the upper surface. Thus fossils of invertebrates were seen in very old Palaeozoic era. Later were seen fossils of Pisces, Amphibia and Reptilia. The Mesozoic era was dominated by reptiles while Coenozoic era showed presence of mammals.
In this way, study of fossils unfold the evolutionary secrets.

f. Write evolutionary history of modern man.
Answer:
(1) Ancestors of humans developed from animals which resembled lemur like animals.
(2) Around seven crore years ago, monkey-like animals evolved from some of these lemur like animals.
(3) Then after about 4 crore years ago, in Africa the tails of these monkey like creatures very gradually disappeared.
(4) Simultaneously, there was enlargement in their body and brain volume too. The hands also improved and were provided with opposable thumb. In this way, ape-like animals were evolved.
(5) These ape-like animals independently gave rise to two lines of evolution, one giving rise to apes like gibbon and orangutan in the South and North-East Asia and gorilla and chimpanzee which stayed in Africa around 2.5 crores of years ago.
(6) The other line of evolution gave rise to human like animals around 2 crore years ago.
(7) The climate became dry and this resulted into reduction of forest cover. This made arboreal apes to descend on the land and start terrestrial mode.
(8) Due to this, there were changes in the pefvic
girdle and vertebral column. The hands were also freed from locomotion and thus they became more manipulative.
(9) Later, journey of hominoid species started from around 2 crores years ago. The first record of human like animal is ‘Ramapithecus’ ape from East Africa.
(10) Ramapithecus → Australopithecus → Neanderthal man → Cro-Magnon are the important steps in human evolution.
(11) Neanderthal man was said to be the first wise man. The increasing growth of brain made man more and more intelligent and thinking animal.
(12) Later, more than biological evolution, it was cultural evolution, when man started agriculture, animal , rearing. There was development of civilizations, arts and science etc. About 200 years ago there were industrial inventions and thus man now rules the earth.

Project:

Project 1.
Make a presentation on human evolution using various computer softwares and arrange a group disscussion over it in the class room.

Project 2.
Read the book – ‘Pruthvivur Manus Uparcich’ written by Late Dr. Sureshchandra Nadkarni and note your opinion on evolution.

Can you recall? (Text Book Page No. 1)

Question 1.
Which component of the cellular nucleus of living organisms carries hereditary characters?
Answer:
The chromosomes made up of nucleic acids and proteins, present in the nucleus of the cell are the components that carry hereditary characters in living organisms.

Question 2.
What do we call the process of transfer of physical and mental characters from parents to the progeny?
Answer:
The process of transfer of physical and mental characters from parents to the progeny is called inheritance or heredity.

Question 3.
Which are the components of the DNA molecule?
Answer:
DNA molecule is made up of two helical strands consisting of deoxyribose sugar, phosphoric acid and pairs of nitrogenous bases. These three together is called a nucleotide.

Choose the correct alternative and write its alphabet against the sub-question number:

Question 1.
Darwin has published a book titled …………..
(a) Natural selection
(b) Mutation
(c) Fall of a sparrow
(d) Origin of species
Answer:
(d) Origin of species

Question 2.
The …………. man evolved about 50 thousand years ago.
(a) Cro Magnon
(b) Neanderthal
(c) Java man
(d) Ramapithecus
Answer:
(a) Cro Magnon

Question 3.
About 10 thousand years ago, ………….. started to practise agriculture.
(a) Gorilla
(b) wise man
(c) Ramapithecus
(d) Australopithecus
Answer:
(b) wise man

Question 4.
………………. can be considered as the first example of wise-man.
(a) Australopithecus
(b) Ramapithecus
(c) Cro Magnon
(d) Neanderthal man
Answer:
(d) Neanderthal man

Question 5.
………. is a connecting link between Annelida and Arthropoda. (March 2019)
(a) Duck-billed platypus
(b) Peripatus
(c) Lung fish
(d) Whale
Answer:
(b) Peripatus

Question 6.
………… years ago human brain was sufficiently evolved to call him wise man.
(a) 50,000
(b) 30,000
(c) 20,000
(d) 10,000
Answer:
(a) 50,000

Question 7.
The process by which the gene in the nucleotide suddenly changes its position is called ………. (Board’s Model Activity Sheet)
(a) translation
(b) translocation
(c) mutation
(d) transcription
Answer:
(c) mutation

Question 8.
…………. is not the vestigial organ in the human body. (Board’s Model Activity Sheet)
(a) appendix
(b) Coccyx
(c) Canine
(d) Wisdom teeth
Answer:
(c) Canine

Write whether the following statements are true or false with proper justification for your answer:

Question 1.
It takes thousands of years for a useful structure to disappear.
Answer:
False. (The useful structures of the body do not disappear. The functioning of the body is easier due to such organs. It takes thousands of years for a functionless organ to disappear.)

Question 2.
Dr. Har Govind Khorana was awarded Nobel prize for his invention and publication in the journal Radio carbon.
Answer:
False. (Willard Libby was awarded Nobel prize for his invention and publication in the journal Radio carbon.)

Question 3.
Mesozoic era was dominated by variety of mammals.
Answer:
False. (Mesozoic era dominated by variety of reptiles.)

Question 4.
It seems that invertebrates have been slowly originated from vertebrates.
Answer:
False. (Vertebrates have been slowly originated from invertebrates in course of evolution. The primitive type of organisms always give rise to complex life forms. The invertebrates from Palaeozoic era gradually gave rise to vertebrates.)

Question 5.
The decaying process of C-12 occurs continuously from the dead remains of living organisms.
Answer:
False. (The decaying process of C-14 occurs continuously from the dead remains of living organisms. C-12 is not radioactive and hence it does not show decaying process.)

Question 6.
The theory of natural selection which mentions ‘Survival of fittest’ is given by Lamarck.
Answer:
False. (The theory of natural selection which mentions ‘Survival of fittest’ is given by Darwin.)

Question 7.
Changes acquired during life time are transferred to next generation.
Answer:
False. (Changes acquired during life time are not heritable. They are not transferred to next generation. Only the genes are transferred to the next generation.)

Question 8.
Each species grows in specific geographical conditions and has specific food, habitat, reproductive ability and period.
Answer:
True. (Each species has specifically evolved characters due to evolution and speciation.)

Question 9.
Humans walking with upright posture were confined to Africa only during prehistoric period.
Answer:
False. (Humans walking upright existed in Africa and China, Indonesia of Asian continent too.)

Question 10.
Industrial society was established about 200 years ago.
Answer:
True. (After the development and specialization of human brain, he started indulging in science and technology. Before; this period the idea of industrialization was not existing.)

Match the columns:

Question 1.

Scientist	Discovery
(1) Johann Gregor Mendel	(a) Chromosomes of grasshopper
(2) Hugo de Vries	(b) DNA is genetic material
	(c) Pioneer of the modern genetics
	(d) Mutational theory

Answer:
(1) Johann Gregor Mendel – Pioneer of the modern genetics.
(2) Hugo de Vries – Mutational theory.

Question 2.

Scientist	Discovery
(1) Walter, Sutton	(a) Chromosomes of grasshopper
(2) Mclyn McCarthy	(b) DNA is genetic material
	(c) Pioneer of the modern genetics
	(d) Mutational theory

Answer:
(1) Walter, Sutton – Chromosomes of grasshopper.
(2) Mclyn McCarthy – DNA is genetic material.

Question 3.

Evidences of evolution	Examples
(1) Morphological evidences	(a) Duck billed Platypus and Peripatus
(2) Anatomical evidences	(b) Remnants and impressions
	(c) Human hand and fore limb of bull
	(d) Shape and venation of leaf

Answer:
(1) Morphological evidences – Shape and venation of leaf.
(2) Anatomical evidences – Human hand and fore limb of bull.

Question 4.

Evidences of evolution	Examples
(1) Palaeontological evidences	(a) Duck billed Platypus and Peripatus
(2) Connecting links	(b) Remnants and impressions
	(c) Coccyx and wisdom tooth
	(d) Human hand and fore limb of cat

Answer:
(1) Palaeontological evidences – Remnants and impressions.
(2) Connecting links – Duck billed Platypus and Peripatus.

Find the odd one out:

Question 1.
Transcription, Translation, Translocation, Mutation
Answer:
Mutation. (All others are stages of protein synthesis.)

Question 2.
Bones of the hands, structure of nostrils, position of eyes, structure of ear pinnae
Answer:
Bones of the hands. (All the others are morphological evidences.)

Question 3.
Venation, Shape of seeds, Leaf petiole, Leaf shape
Answer:
Shape of seeds. (All the others are morphological evidences in plants.)

Question 4.
Human hand, wing of cockroach, forelimb of bull, flipper of whale
Answer:
Wing of cockroach. (All others are anatomical evidences, they are homologous organs.)

Identify the correlation between the first two words and suggest the suitable words in the fourth place:

Question 1.
mRNA : Transcription :: tRNA :…………
Answer:
Translation

Question 2.
Peripatus : Connecting link :: Appendix :……….
Answer:
Vestigial organs

Question 3.
Open circulatory system : Arthropods :: Thin cuticle and parapodia :………..
Answer:
Annelida

Question 4.
Between Annelida and Arthropoda : Peripatus ::……….: Lungfish
Answer:
Pisces/Fish and Amphibia

Question 5.
Theory of natural selection : Charles Robert Darwin :: Theory of inheritance of acquired characters :…………
Answer:
Jean Baptiste Lamarck

Question 6.
Survival of fittest : Darwin :: Acquired characters :……….
Answer:
Lamark

Question 7.
Wisdom teeth : Vestigial organs :: Lungfish :………..
Answer:
Connecting link.

Define the following:

Question 1.
Heredity.
Answer:
The transfer of biological characters from one generation to another through genes is called heredity.

Question 2.
Transcription.
Answer:

Question 3.
Translation.
Answer:
The process of bringing tRNA possessing anticodon that is complementary to the codon on mRNA for protein synthesis is called translation.

Question 4.
Translocation.
Answer:
The process of movement of the ribosome from one end of mRNA to other end by the distance of one triplet codon is called translocation.

Question 5.
Mutation.
Answer:
Sudden and drastic change that occurs in the genetic material is called mutation.

Question 6.
Species.
Answer:
The group of organisms that cap produce fertile individuals through natural reproduction is called a species.

Name the following:

Question 1.
Three Scientists who proved that except viruses, all living organisms have DNA as genetic material.
Answer:
Oswald Avery, Mclyn McCarthy and Colin MacLeod.

Question 2.
Genetic disorder caused due to mutation:
Answer:
Sickle cell anaemia.

Question 3.
Fish that can breathe with help of lungs:
Answer:
Lung fish.

Question 4.
Vestigial organs in human beings:
Answer:
Appendix, tail-bone or coccyx, wisdom teeth and body hair.

Question 5.
Important stages in the journey of human evolution:
Answer:

Animals like Lemur
Egyptopithecus
Dryopithecus
Ramapithecus
Australopithecus
Skilled Human
Homo erectus i.e. Man with erect posture
Neanderthal man
Cro-Magnon man.

Distinguish between the following:

Question 1.
Transcription and Translation.
Answer:
Transcription:

In the process of transcription, the sequence of nucleotides present on the DNA molecule is copied
and carried to the cytoplasm by mRNA.
The process of transcription takes place in nucleus.
During transcription, RNA is produced from DNA.
Only mRNA takes part in transcription.

Translation:

In the process of translation, the specific amino acids are picked up according to the codons brought by mRNA.
The process of translation takes place in ribosomes located in cytoplasm.
During translation, proteins are produced with the help of RNA.
mRNA, tRNA and rRNA take part in translation.

Question 2.
Ape and Human.
Answer:
Ape:

Brain of the apes is smaller in size.
Ape cannot walk upright.
Ape is less intelligent as compared to human.
Apes are arboreal in their habitat and they spend more time on the trees.
The forelimbs of ape are longer than the hind limbs.

Human:

Brain of humans is larger in size.
Humans can walk upright.
Human is considered to be the most intelligent animal.
Humans are terrestrial in their habitat. They cannot stay on the trees.
The forelimbs of humans are shorter than the hind limbs.

Give scientific reasons:

Question 1.
Some of the characters of parents are seen in their offspring.
Answer:

The parental genes are transferred to their progeny through male and female gametes.
These genes carry hereditary characters.
Since they are transmitted from the parents to their offspring, one can see the parental characters in their offspring.

Question 2.
Darwin’s work on evolution has been a milestone.
Answer:
(1) Darwin has proposed two very important theories of evolution, viz. Theory of natural selection and Theory of origin of species.
(2) The evolution has taken place on the earth for last many crores of years.
(3) The exact nature and process of these evolutionary changes become clear after studying Darwinism. (4) The observations made by Darwin at that time are now tested according to the modern development in science and are found to be correct. Thus, his work is said to be a milestone.

Question 3.
Peripatus is said to be a connecting link between Annelida and Arthropoda.
Answer:

Peripatus shows segmented body, thin cuticle, and parapodia-like organs.
These characters are typical of Annelids.
Similarly, it also shows tracheal respiration and open circulatory system which is a characteristic feature of Arthropods.
Since Peripatus shares both these characters, it is said to be a connecting link between j Annelida and Arthropoda.

Question 4.
Vertebrates have been slowly originated from invertebrates.
Answer:

When the carbon dating method was used to assess the age of fossils, it was understood that invertebrates were present on the earth much before the vertebrates.
The fossils of invertebrates are present in lower layers of earth’s strata.
They were seen in Palaeozoic era of geological time period. Vertebrates dominated during Coenozoic era.
Their fossils are seen in the upper strata of the earth’s crust.
The structural complexity also increased in vertebrates. All these facts indicate that Vertebrates have slowly originated from invertebrates.

Question 5.
During human evolution the hands became available for use.
Answer:

During human evolution, the climate of earth started becoming dry.
This resulted in loss of forest cover.
The apes which were arboreal on the trees thus descended and started walking on land.
The lumbar bones underwent change and the apes started walking upright on the grasslands.
The vertebral column also underwent change. Due to upright posture the forelimbs were freed from locomotion.
The legs started bearing the weight of the body and the hands became available for use.

Read the following statements and justify the same in your own words with the help of suitable examples:

Question 1.
Geographical and reproductive isolation of organisms gradually leads to speciation.
Answer:

Every species survives in specific geographical conditions. The requirements of food and habitat, is specific for each species. Their reproductive ability and period is also different.
Therefore, the individuals from one species cannot reproduce with individuals from other species.
When they are separated by a distance or geographical barriers they are said to be isolated geographically.
When they cannot reproduce with each other, they are said to be isolated reproductively.
The ancestor species of both these subspecies may be the same but due to isolation over a very long-time duration, there is genetic variation between the two. Therefore, the isolation leads to speciation.

Question 2.
Study of fossils is an important aspect of study of evolution.
Answer:
(1) Fossils offer palaeontological evidence for the evolutionary process.
(2) Due to some natural calamities the organisms get buried during ancient times.
(3) The impressions and remnants of such organisms remain preserved underground. The hot lava also traps some organisms or their impressions. All such formations form fossils.
(4) Study of fossils help the researcher to understand the characteristics of the organisms that existed in the.past.
(5) Carbon dating method also helps in finding out exact age of the fossil. According to the structure of earth’s crust the fossils are obtained at specific depths.
(6) The oldest ones are obtained at the depth while the relatively recent ones occupy the upper surface. Thus fossils of invertebrates were seen in very old Palaeozoic era. Later were seen fossils of Pisces, Amphibia and Reptilia. The Mesozoic era was dominated by reptiles while Coenozoic era showed presence of mammals.
(7) In this way, study of fossils unfold the evolutionary secrets.

Question 3.
There is evidences of fatal Science among chordates.
[Please read the above question as: Among different chordates there are embryological evidences.]
Answer:

Very young embryos of fish, amphibians, reptiles, birds and mammals show quite similar structure in the early stages.
As the further growth takes place, they acquire different patterns.
The initial similarity between the vertebrate embryos is an evidence that during evolution, there was a common ancestor for all the vertebrate classes.
This is called embryological evidence for vertebrate evolution.

Question 4.
Human evolution began approximately 7 crore years ago.
Answer:

Approximately around 7 crore years back the ice age began on the earth. In such conditions, dinosaurs became extinct. The evolution and diversity of mammals started during this time. Due to change in climate the forest cover also declined rapidly.
Ancestors of monkey-like animals were Lemur like animals which evolved during this time period.
The tails of these monkey-like creatures started vanishing very gradually around 4 crore years ago.
The body and brain both increased in volume forming first ape like animals. The monkey like ancestors gave rise to two evolutionary links to apes and human like animals.
Later, the human evolution took place by changes in the brain volume, the ability to walk upright, excessive use of hand for manipulations.
This journey of human evolution began 7 crore years ago. But the true wise and intelligent man arose around 50,000 years ago.

Answer the following questions:

Question 1.
Answer the following questions: (March 2019)
(a) What do you mean by central dogma?
Answer:
Information about protein synthesis is present in DNA. As per this information, proteins are produced by DNA through RNA molecules. This is called central dogma.

(b) What is transcription?
Answer:
The process of synthesis of mRNA as per the nucleotide sequence present in DNA is called transcription. The nucleotide sequence on mRNA is complimentary to that of the single DNA strand used in synthesis. Instead of thymine, mRNA possesses uracil.

(c) What is meant by triplet codon?
Answer:
The code for each amino acids always consists of three nucleotides which is known as triplet codon.

Question 2.
Which animal is called a connecting link between Reptiles and Mammals? (Board’s Model Activity Sheet)
Answer:
Duck billed platypus is called a connecting link between Reptiles and Mammals.

Question 3.
In which way is science of heredity useful these days?
Answer:
The science of heredity is useful in the following ways:

For diagnosis of hereditary disorders.
For treatment of hereditary disorders
For prevention of hereditary disorders
For production of hybrid varieties of animals and plants
For using microbes in the industrial processes.

Question 4.
What is meant by carbon dating method?
Answer:
(1) Carbon dating method is technique used for determining the age of fossils.
(2) After the death of the organisms, their consumption of carbon stops. But right from that moment the decaying process of C-14 occurs continuously.
(3) This results in change in the ratio between C-14 and C-12. C-12 is not radioactive as C-14.
(4) Thus the time passed since the death of a plant or animal is calculated by measuring the radioactivity of C-14 and ratio of C-14 to C-12 present in their body.
(5) The points noted during carbon dating are:

The period after the organism has been dead.
The activity of C-14 in the dead organism.
Ratio between C-14 and C-12.

Question 5.
Answer the following questions:
(a) Describe briefly the Darwin’s theory of natural selection.
Answer:
Charles Darwin (1809-1882) proposed the theory of natural selection.
Theory of natural selection: ‘The survival of fittest’, i.e., organisms which are fit for survival, evolve while those that are not, perish. The natural selection thus acts to produce new species.

(b) What were the objections raised against Darwinism?
Answer:
Objections raised against Darwinism:

There are other factors too for evolution and just not the Natural Selection.
Arrival of useful and useless modifications were not explained by Darwin, though he said about the survival of the fittest.
He has not given any explanation about slow changes and abrupt changes occurring during evolution.

(c) Which book was published by Darwin to explain this theory? (Board’s Model Activity Sheet)
Answer:
Charles Darwin wrote the book ‘Origin of Species’.

Question 6.
What were the objections raised against Darwinism?
Answer:
Some of the main objections raised against Darwinism are as follows:

There are other factors too for evolution and just not the Natural Selection.
Arrival of useful and useless modifications were not explained by Darwin, though he said about the survival of the fittest.
He has not given any explanation about slow changes and abrupt changes occurring during evolution.

Question 7.
Answer the following questions:
(a) Explain in brief-Lamarck’s principle of ‘use or disuse of organs’.
Answer:
The theory of use and disuse of organs says that the morphological characters of organism develop because of specific activities that the organisms perform. If some organ is not used it gets degenerated. If excessively, used, it develops. Thus, the morphological changes take place due to activities or non-working of a particular body parts in an organism.

(b) Give two examples.
Answer:
Due to constant extension of neck to eat foliage from the top of the trees, giraffe’s neck became long. Similarly, blacksmith has strong arms due to constant work. The flightless ostrich and emu did not fly and hence their wings became useless. Aquatic birds like swan and duck made their feet suitable for swimming by living in water. Snake lost limbs as it tried burrowing mode.

(c) What are acquired characters?
Answer:
Acquired characters are those characters which are obtained during the life time by any organism and passed on to next generations.

Write short notes:
(OR)
Write short notes based upon the information known to you:

Question 1.
Theory of evolution.
Answer:

According to the theory of evolution, first living material was in the form of protoplasm which was formed in ocean.
Gradually, it gave rise to unicellular organisms. Changes took place in these unicellular organisms which made them evolve into larger and more complex organisms.
All evolutionary changes were very slow and gradual taking about 300 crore years to happen.
Different types of organisms were developed as the changes and development that occurred in living organisms was all round and multi-dimensional.
Hence, this overall process of evolution is called organizational and progressive.
Variety of plants and animals developed from the ancestors having different structural and functional organization during the process of evolution.

By choosing appropriate words given in the bracket, complete the paragraph:

Question 1.
(translation, anticodon, tRNA, mRNA, amino acids, triplet codon, transcription, DNA)
The …….. formed in nucleus comes in cytoplasm. It brings in the coded message from DNA. The message contains the codes for amino acids. The code for each amino acid consists of three nucleotides. It is called as ‘………..’. Each mRNA is made up of thousands of triplet codons. As per the message on mRNA, ……… are supplied by the ………. For this purpose, tRNA has ‘…………’ having complementary sequence to the codon on mRNA. This is called ‘………..’.
Answer:
The mRNA formed in nucleus comes in cytoplasm. It brings in the coded message from DNA. The message contains the codes for amino acids. The code for each amino acid consists of three nucleotides. It is called as ‘triplet codon’. Each mRNA is made up of thousands of triplet codons. As per the message on mRNA, amino acids are supplied by the tRNA. For this purpose, tRNA has ‘anticodon’ having complementary sequence to the codon on mRNA. This is called ‘translation’.

Question 2.
(Cultural, agriculture, fire, brain, Cro-Magnon, Homo sapiens, Neanderthal)
Evolution of upright man continued in the direction of developing its ………. for the period of about 1 lakh years and meanwhile he discovered the ………. Brain of man, 50 thousand years ago had been sufficiently evolved to the extent that it could be considered as member of the species ………… Neanderthal man can be considered as the first example of wise-man. The ……….. man evolved about 50 thousand years ago and afterwards, this evolution had been faster than the earlier. About 10 thousand years ago, wise-man started to practise the ………. It started to rear the cattle-herds and established the cities. ………..development took place later.
Answer:
Evolution of upright man continued in the direction of developing its brain for the period of about 1 lakh years and meanwhile he discovered the fire. Brain of man 50 thousand years ago had been sufficiently evolved to the extent that it could be considered as member of the species Homo sapiens. Neanderthal man can be considered as the first example of wise-man. The Cro-Magnon man eyolved about 50 thousand years ago and afterwards, this evolution had been faster than the earlier. About 10 thousand years ago, wise-man started-to practise the agriculture. It started to rear the cattle-herds and established the cities. Cultural development took place later.

Read the paragraph and answer the questions given below:

With the help of RNA, the genes present in the form of DNA participate in the functioning of cell and thereby control the structure and functioning of the body. Information about protein synthesis is stored in the DNA and synthesis of appropriate proteins as per requirement is necessary for body. These proteins are synthesized by DNA through the RNA. This is called ‘Central Dogma’. mRNA is produced as per the sequence of nucleotides on DNA. Only one of the two strands of DNA is used in this process. The sequence of nucleotides in mRNA being produced is always complementary to the DNA strand used for synthesis. Besides, there is uracil in RNA instead of thymine of DNA. This process of RNA synthesis is called ‘transcription’.

Questions and Answers:

Question 1.
Which part of the cell control the structure and functioning of the body?
Answer:
Genes present in the form of DNA along with RNA control the structure and functioning of the body.

Question 2.
How is a specific protein synthesised in the cell?
Answer:
The information of protein synthesis is stored in the DNA which is utilised as per the requirement of the body. Later the proteins are synthesised by DNA through the RNA.

Question3.
What is the similarity between mRNA and DNA?
Answer:
The sequence of nucleotides on DNA is copied on mRNA. The nucleotide sequence on mRNA is thus complementary to DNA.

Question 4.
Give one difference between RNA and DNA.
Answer:
RNA has uracil instead of thymine which is present in DNA.

Question 5.
Define central dogma.
Answer:
Central dogma is the concept that proteins are synthesised by DNA through the RNA.

Diagram-based questions:

Question 1.
Observe the figure 1.3 of transcription given on page 9 in this chapter and answer the following questions:

(1) What is the sequence of nucleotides present on one strand of the DNA?
Answer:
A T G C A A T T

(2) According to the above sequence on DNA, what will be the transcribed sequence on the mRNA molecule?
Answer:
U A C G U U A A

(3) Which enzyme is taking part in the above process of transcription?
Answer:
RNA polymerase takes part in the process of transcription.

Question 2.
Observe the figure 1.5 of translation and translocation, given on page 9 this chapter and answer the following questions:

(1) Which is the initiation codon? Where is it present?
Answer:
AUG is the initiation codon, which is present on the mRNA.

(2) What are the types of RNA present inside the ribosome? Which triplet codon is present on it?
Answer:
There are two molecules of tRNA present inside the ribosome. The triplet codons present on them are UAC and AAG respectively.

(3) Which genetic code is present on mRNA that is leaving the nucleus? What must be the sequence on the DNA to have such code on mRNA?
Answer:
The mRNA that leaves the nucleus has genetic code: A U G U U C A A A
The genetic code on DNA therefore should be as follows: T A C A A G T T T

Question 3.
Observe the figure 1.6 given on page 10 from this chapter. Answer the following question based on your observations:

What is the significance of this figure from the viewpoint of evolution? Explain in brief.
Answer:
In the figure, the process of mutation is shown. The original nucleotide sequence of TGC is replaced by new mutated sequence GAT. The change in the nucleotide sequence will change the DNA.

This will result in the change in genes and then changing the hereditary characters. Due to such change in genes, the evolution proceeds. The mutation so formed can be minor or major. The greater the impact of the change, the evolution takes place rapidly. The mutation thereby produce recombinations leading to diversity.

Question 4.
Observe the picture and answer the following questions:

(1) Which evidence of evolution is shown in the picture?
Answer:
Embryological evidences of evolution are shown in this picture.

(2) What can be proven with this proof?
Answer:
The similarities in the initial embryonic stages of different vertebrates shows that there was a common origin of all of them. Thus embryological evidences prove that there was common vertebrate ancestor.

(3) Give one more example of evidence of evolution.
Answer:
Palaeontological evidences such as vestigial organs and connecting links are another examples of evolutionary evidences.

Question 5.
Which concept/theory do you remember after seeing this picture of Giraffes? Describe it in brief.

Answer:

The picture is based on the Lamarck’s principle of ‘use and disuse of organs’.
The morphological characters of organism develop because of specific activities that the organisms perform.
If some organ is not used it gets degenerated. If excessively used, it develops further.
Thus, the morphological changes take place due to activities or non-working of a particular body parts in an organism. Due to constant extension of neck to eat foliage from the top of the trees, giraffe’s neck became long.

Activity-based Questions:

Try this: (Text Book Page No. 4)

Observe the above images and note the similarities between given animal images and plant images.
Answer:
The above pictures of the animals show similarities such as structure of mouth, position of eyes, structure of nostrils and ear pinnae and body fur. In pictures of plants there are similarities in characters like leaf shape, leaf venation, leaf petiole, etc.
These above morphological evidences show that there may be a common ancestor for all of the species shown.

Observe and Discuss:

Question 1.
Observe the pictures given below. (Text Book Page No. 5)

Answer:
(1) Fossils offer palaeontological evidence for the evolutionary process.
(2) Due to some natural calamities the organisms get buried during ancient times.
(3) The impressions and remnants of such organisms remain preserved underground. The hot lava also traps some organisms or their impressions. All such formations form fossils.
(4) Study of fossils help the researcher to understand the characteristics of the organisms that existed in the.past.
(5) Carbon dating method also helps in finding out exact age of the fossil. According to the structure of earth’s crust the fossils are obtained at specific depths.
(6) The oldest ones are obtained at the depth while the relatively recent ones occupy the upper surface. Thus fossils of invertebrates were seen in very old Palaeozoic era. Later were seen fossils of Pisces, Amphibia and Reptilia. The Mesozoic era was dominated by reptiles while Coenozoic era showed presence of mammals.
(7) In this way, study of fossils unfold the evolutionary secrets.

Question 2.
Observe the pictures given and discuss the characters observed. (Text Book Page No. 6)

Answer:
Some living organisms possess some characters in them which are the distinctive features of different groups or phyla. Such individuals connect these two groups by sharing the characters of both and hence they are known as connective links.

Project: (Do it your self)

Project 1.
Internet is my friend: (Text Book Page No. 3)
Collect the information from the internet about Big-Bang theory related with the formation of stars and planets and present it in your class.

Project 2.
Use of ICT: (Text Book Page No. 4)
Collect the information of geological dating and present it in the classroom.

Project 3.
Use of ICT: (Text Book Page No. 5)
Find how the vestigial organs in certain animals are functional in others. Present the information in your class and send it to others.

Project 4.
Internet is my friend: (Text Book Page No. 8)
Collect the pictures and information of various species of monkeys from internet.

Class 10 Questions And Answers

10th Std Science Part 2 Questions And Answers:

Living World and Classification of Microbes Class 8 Science Chapter 1 Questions And Answers Maharashtra Board

February 6, 2025January 5, 2025 by Bhagya

Balbharti Maharashtra State Board Class 8 Science Solutions Chapter 1 Living World and Classification of Microbes Notes, Textbook Exercise Important Questions and Answers.

Std 8 Science Chapter 1 Living World and Classification of Microbes Question Answer Maharashtra Board

Class 8 Science Chapter 1 Living World and Classification of Microbes Question Answer Maharashtra Board

1. Use Whittaker method to classify bacteria, protozoa, fungi, algae, prokaryotic, eukaryotic, microbes.

Living World And Classification Of Microbes Exercises Question 1.
Use Whittaker method to classify bacteria, protozoa, fungi, algae, prokaryotic, eukaryotic, microbes.
Answer:

Bacteria: Kingdom Monera
Protozoa: Kingdom Protista
Fungi: Kingdom Fungi
Algae: If unicellular, Kingdom Protista. If multicellular, Kingdom Plantae
Prokaryotic: Kingdom Monera
Eukaryotic: Any kingdom other than Monera.
Microbes: Kingdom Monera or Protista.

2. Complete the five kingdom method of classification using-living organism, prokaryotes, eukaryotes, multicellular, unicellular, protista, animals, plants, fungi.

Living World And Classification Of MicrobesQuestion 1.
Complete the five kingdom method of classification using-living organism, prokaryotes, eukaryotes, multicellular, unicellular, protista, animals, plants, fungi.

Answer:

3. Find out my partner

Question 1.

Answer:

A	B
1. Fungi	Candida
2. Protozoa	Amoeba
3. Virus	Bacteriophage
4. Algae	Chlorella
5. Bacteria	Prokaryotic.

4. State whether the following statements are True or False. Explain your statement:

Question a.
Lactobacilli are harmful bacteria.
Answer:
False.
Explanation Lactobacilli are useful bacteria. They are used for curdling the milk. They are also used for preparing variety of milk products.

Question b.
Cell wall of fungi is made up of chitin.
Answer:
True.
Explanation The cell wall of the plants is made up of cellulose while the cell wall of fungi is made up of complex sugar called chitin. Inside the fungal cell wall there is cytoplasm which contains many nuclei.

Question d.
Organ of locomotion in amoeba is pseudopodia.
Answer:
True.
Explanation Amoeba is a protozoan, primitive organism which possesses pseudopodia as the organ for locomotion.

Question e.
Tomato wilt is a viral disease.
Answer:
True.
Explanation: Tomato wilt is a viral disease. These viruses are able to infect only plant cells.

5. Give answers

Question a.
State the merits of Whittaker’s method of classification.
Answer:
For the answer of Merits of Whittaker’s method refer to point I of answer given on this Digest’s page no. 11; under “Use your brain power!”

Question b.
Write the characteristics of viruses.
Answer:
1. Viruses are extremely minute of the size range of 10 nrn to 100 nm. They are on the borderline of living and non-living. They are 10 to 100 times smaller than bacteria and are visible only through the electron microscope.

2. Though they are not considered as living, they can make replica of their own.
3. They exist in the form of independent particles. They are long molecules of DNA or RNA which are covered by a protein coat.

4. Their survival is possible only inside the living plant or animal cells. When they infect the host cells, they produce their own proteins with the machinery of the host cell. These proteins form many replicas of the infecting virus.

5. This infection destroys the host cell and the virus replicas are released. These free replicas re-infect the other adjoining cells of the host.
6. Most of the viruses are pathogenic, they cause diseases in plants and animals.

Question c.
Explain the nutrition in fungi.
Answer:
Most of the fungi are saprophytic in their nutrition. They absorb the nourishment from dead and decaying matter. By taking the organic matter from dead bodies of plants and animals, fungi survive. In this process they degrade the organic matter completely.

Question d.
Which living organisms are included in the kingdom Monera?
Answer:

All the living organisms belonging to Kingdom Monera are unicellular.
The mode of nutrition in them is either autotrophic or heterotrophic.
All of them are prokaryotic and thus they do not have well-formed nucleus. The nuclear membrane and the cell organelles are absent in them.
Kingdom Monera consists of different types of bacteria and blue-green algae.

E.g. Bacteria Clostridium titani, Vibrio choleri, Treponema pallidum, Streptococcus pneumoniae, Legionella pneumoniae, Salmonella typhi, Staphylococcus aureus, Clostridium botulinum.

6. Who am I?

Question a.
I don’t have true nucleus, cell organelles or plasma membrane.
Answer:
Microbe from Monera

Question b.
I have nucleus and membrane bound cell organelles.
Answer:
Protozoan from Protista/I am any one of Eukaryote

Question c.
I live on decaying organic matter.
Answer:
Fungus

Question d.
I reproduce mainly by cell division. (*Binary fission)
Answer:
Bacteria and some Protozoa.

Question e.
I can produce my replica.
Answer:
Virus

Question f.
I am green, but don’t have organs.
Answer:
Algae

7. Draw neat and labelled diagrams.

Question a.
Different types of bacteria:
Answer:

Question b.
Paramoecium:
Answer:

Question c.
Bacteriophage
Answer:

8. Arrange the following in ascending order of size Bacteria, Fungi, Viruses, Algae.

Question a.
Arrange the following ¡n ascending order of size Bacteria, Fungi, Viruses, Algae.
Answer:
Viruses, Bacteria, Fungi, Algae.

Project:

Question 1.
Prepare a chart showing infectious bacteria and the diseases caused by them.

Question 2.
Visit a nearby pathology lab. Get the information about pathogenic microbes, methods to observe them, different microscopes from the technicians there.

Class 8 Science Chapter 1 Living World and Classification of Microbes Additional Important Questions and Answers

Rewrite the sentences after filling the blanks:

Question 1.
The process of dividing living organism into groups and subgroups is called …………… .
Answer:
Biological classification.

Question 2.
Organisms with cell wall but not able to perform photosynthesis are called …………… .
Answer:
Fungi.

Question 3.
Most of the fungi are …………… .
Answer:
saprotrophic.

Question 4.
Viruses can be seen only with …………… .
Answer:
electron microscope.

Question 5.
…………… viruses attack bacteria.
Answer:
Bacteriophage

Question 6.
In fungi the cell wall is made up of j tough and complex sugar called …………… .
Answer:
‘Chitin’.

State whether the following statements are True or False. Explain your statement:

Question 1.
Plasmodium causes dysentery.
Answer:
False.
Explanation Plasmodium causes malaria. Entamoeba histolytica causes amoebic dysentery or amoebiasis.

Find out my partner

Question 1.

Scientist	Pattern of classification
1. Carl Linnaeus	(a) 5 groups of living organisms
2. Haeckel	(b) 2 groups as Prokaryotes and Eukaryotes
3. Chatton	(c) 4 groups as Monera, Protista, Plants and Animals
4. Kopland	(d) 3 kingdoms – Protista, Plants and Animals.
5. Whittaker	(e) 2 kingdoms of living organisms

Answer:

Scientist	Pattern of classification
1. Carl Linnaeus	(e) 2 kingdoms of living organisms
2. Haeckel	(d) 3 kingdoms – Protista, Plants and Animals.
3. Chatton	(b) 2 groups as Prokaryotes and Eukaryotes
4. Kopland	(c) 4 groups as Monera, Protista, Plants and Animals
5. Whittaker	(a) 5 groups of living organisms

Question 2.

Living organism	Group
1. Clostridium titani	(a) Heterotrophic Protista
2. Paramoecium	(b) Fungi
3. Chlamydomonas	(c) Bacteria belonging to Monera
4. Baker’s yeast	(d) Algae
	(e) Virus

Answer:

Living organism	Group
1. Clostridium titani	(c) Bacteria belonging to Monera
2. Paramoecium	(a) Heterotrophic Protista
3. Chlamydomonas	(d) Algae
4. Baker’s yeast	((b) Fungi
	(e) Virus

Question 3.

Microbes	Size
1. Virus	(a) 1 μm to 10 μm
2. Algae	(b) 200 μm
3. Protozoa	(c) 10 μm to 100μm
4. Bacteria	(d) 10 nm to 100 nm

Answer:

Microbes	Size
1. Virus	(d) 10 nm to 100 nm
2. Algae	(c) 10 μm to 100 μm
3. Protozoa	(b) 200 μm
4. Bacteria	(a) 1 μm to 10 μm

Name the following/ Give examples

Question 1.
Three organs of locomotion in Protista
Answer:

Pseudopodia
Cilia
Flagella

Question 2.
Two autotrophic Protista
Answer:

Euglena
Volvox

Question 3.
Institute in India which is involved in research on viruses
Answer:
National Institute of Virology, Pune

Question 4.
Two methods of asexual reproduction in Fungi
Answer:

Binary fission
Budding

Question 5.
Two pathogenic protozoans and the diseases caused by them
Answer:

Entamoeba histolytica causes amoebiasis
Plasmodium vivax – causes malaria.

Answer the following questions in one sentence:

Question 1.
What are the types of living organisms according to their lifestyle?
Answer:
Producers, consumers and decomposers are the types of living organisms according to their lifestyle.

Question 2.
What are the characteristics of prokaryotic cells?
Answer:
Absence of nuclear membrane, well- formed nucleus and lack of cell organelles are the characteristics of the prokaryotic cells.

Question 3.
When do virus destroy the host cells?
Answer:
After synthesising their own proteins and creating numerous replica of their own type, then the virus destroys the host cells.

Give answers:

Question 1.
Which criteria were considered for classification method of Whittaker?
Answer:
The criteria considered for classification by Whittaker are as follows:
1. Complexity of cell structure: Whether the cells of the organisms are prokaryotic or eukaryotic.

2. Complexity of organisms Whether the organisms are unicellular or multicellular is considered.

3. Mode of nutrition Whether the organism is autotrophic and is performing photosynthesis on its own or it is heterotrophic is considered. Plants are autotrophic, fungi are saprotrophic while animals use food from plants or other animals and hence they are heterotrophic.

4. Lifestyle According to nutrition, every living organism is at certain trophic level. This is called lifestyle. Plants are producers, animals are consumers while fungi are decomposers.

5. Phylogenetic relationship When the evolution proceeded gradually, there was transition from prokaryotes to eukaryotes, unicellular to multicellular. In this order the different groups of living organisms were evolved. This is known as phylogenetic relationship.

Use your brain power!
(Textbook page 3)

Question 1.
Explain merits and demerits of Whittaker’s classification.
Answer:
I. Merits of Whittaker’s classification:

The classification system that Whittaker has adapted is totally based on scientific foundation.
Prokaryotes are placed separately in a different kingdom. The prokaryotic organisms are different from other organisms, thus placing them separately is justified.
All unicellular eukaryotic organisms are clubbed together in one kingdom named, Protista. This has helped to solve the placement of Euglena.
Euglena has chloroplasts like plants but as animals it has flagella and thus there was conflict about such species during previous classification systems. It was placed in protozoa previously.
Fungi are saprophytic and hence they are placed separately in a unique kingdom.
According to five kingdom classification, the cell structure, organization of cell, mode of nutrition, lifestyle and phylogenetic relationship are taken into consideration.
Therefore the system of 5 kingdom classification becomes most authentic system of biological classification.

II. Demerits of Whittaker’s method of classification:

1. Some organisms belonging to Monera and Protista have ability to perform photosynthesis. Thus they show mode of nutrition as autotrophic, while others are heterotrophic. Similarly some monerans have cell wall and some Protists also have cell wall. This becomes confusing during their placement.

2. In kingdom Protista, organisms show varied characteristics. In spite of this they are placed together.

3. In kingdoms, Plantae, Animalia and Fungi the organisms having primitive characters and were initial examples during evolution are not included. E.g. In Kingdom Animalia, amoeba is not included though it is said to be unicellular animal. This creates confusion.

4. Similarly if algae are unicellular, they are placed in kingdom Protista and if they are multicellular they are placed in kingdom Plantae. In reality, unicellular and multicellular algae both show much similarity. But due to Whittaker’s classification system they are placed away from each other.

5. Species of algae such as Chlorella, Chlamydomonas are not included in Kingdom Protista.

6. Viruses are not included in any of the kingdoms by Whittaker. Their classification has become a point of debate among the biologists.

Write short notes:

Question 1.
Characteristics of Fungi.
Answer:

The organisms which are placed in kingdom Fungi are multicellular, heterotrophic, non-green, and eukaryotic in nature.
Most of the fungi are saprophytic and they sustain on the dead and decaying organic matter.
The cell wall of the fungal cells is made up of chitin. Chitin is the tough and complex sugar.
Fungi have thread like body. The cytoplasm of the fungal cells contain many nuclei.
The reproduction in Fungi is either sexual or asexual. Asexual reproduction is by fission or by budding.
Examples Baker’s yeast, Candida, Mushroom, Aspergillus (Fungus on corn), Penicillium

Question 2.
Characteristics of Bacteria.
Answer:

Bacteria are microscopic, unicellular, prokaryotic organisms belonging to the kingdom Monera.
Some bacteria are solitary with independent existence. Some are colonial forms.
The bacterial cell lacks well-formed nucleus with nuclear membrane and cell organelles.
Reproduction is by binary fission.
In favourable conditions, bacteria duplicate with a great speed. Within 20 minutes they can double in number.
Bacteria may be round as in Cocci, elongated as in Bacillus, comma shaped as in Vibrio and spiral shaped as in Spirillum.

Question 3.
Characteristics of Protozoa.
Answer:

Protozoa are unicellular, eukaryotic organisms belonging to kingdom, Protista.
They are microscopic of the size of about 200 pm.
They have different organs of locomotion such as pseudopodia, cilia and flagella.?
Reproduction is by asexual method, usually by binary fission. .
Protozoa are seen in varied habitats such as soil, fresh water and marine water.
Some protozoans are parasitic and cause various types of illness in hosts. E.g. Entamoeba histolytica is a species of amoeba that causes amoebiasis. Malaria is caused by Plasmodium vivax.
Protozoa show different modes of nutrition.

E.g. Euglena is autotrophic as it does photosynthesis with the help of 5 chloroplasts present in its body. Amoeba and Paramoecium are heterotrophic and free living seen in contaminated water.

Complete the paragraph using the words given in the brackets

[Monera, Euglena, autotrophic, cell organelles, chitin, nuclear, prokaryotic, viruses, replicas, saprotrophic, viral particles]

In Kingdom ……….. bacteria were included but not ………….. Viruses are on the border line of living and non-living. Do we really call them living? If they are making …………. of their own type, are they not considered as living? Throughout the world they spread hazardous epidemics. Antibiotics do not act on ………… However, bacteria can be controlled by antibiotics. All the living organisms belonging to Monera are with …………… cell. They do not have ………….. membrane and neither they have ……………… But a nice nucleus is seen in …………….., Euglena is ………… protist. The fungi with cell wall of …………….. are ………….. in their mode of nutrition.
Answer:
In Kingdom Monera bacteria were included but not viruses. Viruses are on the border line of living and non-living. Do we really call them living? If they are making replicas of their own type, are they not considered as living? Throughout the world they spread hazardous epidemics. Antibiotics do not act on viral particles. However, bacteria can be controlled by antibiotics. All the living organisms belonging to Monera are with prokaryotic cell. They do not have nuclear membrane and neither they have cell organelles. But a nice nucleus is seen in Euglena. Euglena is autotrophic protist. The fungi with cell wall of chitin are saprotrophic in their mode of nutrition.

Complete the chart:

Question 1.
Draw a chart showing different types of Microorganisms.
Answer:

Draw neat and labelled diagrams:

Question 1.
Fungi:
Answer:

Question 2.
Euglena:
Answer:

Question 3.
Amoeba:
Answer:

Question 4.
Correctly label the various organisms shown in the Kingdom Monera:

Answer:

Streptococcus pneumoniae
Clostridium titani
Vibrio choleri
Treponema pallidum
Staphylococcus aureus
Legionella pneumoniae
Salmonella typhi
Clostridium botulinum

Activity-based questions

1. Try this:
Activity Take a small drop of curd or buttermilk on a clean glass slide. Dilute it with a little water. Carefully keep a coverslip. Observe it under high power of compound microscope. What did you see?
Answer:
In the slide we can see Lactobacilli \ bacteria.

2. Try this:
Activity Prepare a temporary mount of one drop of pond water on a glass slide. Observe it under low power and high power microscope.
Answer:
The drop on the slide shows motile microscopic organisms which have irregular shape. They are amoeba.

3. Try this:
Activity Take a moist piece of bread or bhakri and keep it in a container with lid for 2-3 days. After 2-3 days a fine cotton thread like tuft is found growing on the surface of the bread. Prepare a temporary mount of few threads from this culture and observe it under the microscope.
Answer:
Upon observation of thread like structures the fungal hyphae ( fibre like body) are seen.

MCQs based on experiments:

Choose the appropriate alternative of the following:

Experiment 1: To observe lactobacilli in curd/buttermilk.

Question 1.
Which of the following bacterium is used to make curds from milk?
(a) Streptococcus
(b) Lactobacillus
(c) Staphylococcus
(d) Clostridium
Answer:
(b) Lactobacillus

Question 2.
In which kingdom is Lactobacillus included?
(a) Monera
(b) Protista
(c) Fungi
(d) Plantae
Answer:
(a) Monera

Question 3.
Which is the other organism that has been added in kingdom Monera in addition to bacteria?
(a) Virus
(b) Blue-green algae
(c) Fungi
(d) Protozoa
Answer:
(b) Blue-green algae

Experiment 2: To observe fungus on the bread

Question 1.
In which kingdom is fungus growing on the bread included?
(a) Fungi
(b) Protozoa
(c) Monera
(d) Protista
Answer:
(a) Fungi

Question 2.
What are dark coloured particles which are seen when the fungus is growing on the bread?
(a) Sporangiophore
(b) Rhizoids
(c) spores
d) Columella
Answer:
(c) spores

Question 3.
Why is there growth of fungus on all the stale food?
(a) Fungus has affinity for food.
(b) Fungus grows on decaying organic matter.
(c) As food is open, the fungus drops on it and starts growing.
(d) None of the alternative is correct.
Answer:
(b) Fungus grows on decaying organic matter.

Class 8 Questions And Answers

8th Std Science Questions And Answers:

Environmental management Class 10 Questions And Answers Maharashtra Board

January 6, 2025January 5, 2025 by Bhagya

Balbharti Maharashtra State Board Class 10 Science Solutions Part 2 Chapter 4 Environmental management Notes, Textbook Exercise Important Questions and Answers.

Std 10 Science Part 2 Chapter 3 Environmental management Question Answer Maharashtra Board

Class 10 Science Part 2 Chapter 3 Environmental managementQuestion Answer Maharashtra Board

Question 1.
Reorganize the following food chain. Describe the ecosystem to which it belongs.
Grasshopper – Snake – Paddy field – Eagle – Frog.
Answer:

Correct food chain: Paddy field → Grasshopper → Frog → Snake → Eagle.
Such food chain is seen in the terrestrial ecosystem. There are many biotic factors in the terrestrial ecosystem, such as insects, birds, mammals etc.
The above example mentions about paddy field, so it must be in vicinity of coastal lands. There is water logging in the paddy fields. Therefore, it offers a habitat to the frogs.
In the above example, paddy fields are producers in the ecosystem. The primary consumer is grasshopper. Secondary consumer is frog, tertiary consumer is snake and the apex consumer is eagle. On every trophic level the bacteria, fungi and some scavenging worms can act as the decomposers.
In this ecosystem. the solar energy is transferred from the paddy crops to eagle in a step wise food
chain.

Question 2.
Explain the statement – ‘We have got this Earth planet on lease from our future generations and not as an ancestral property from our ancestors.’
Answer:

The earth was inhabited by older generations before us. We have replaced them.
But during their life time, they have created hazardous impact on the earth. The industrialization, the quest for more and more natural resources, wars fought, the construction activities such as dams, roads and bridges, extensive deforestation, etc. were their thoughtless activities.
All these activities were for development of mankind. But most of them have destroyed the delicate balance between the producers and different levels of consumers.
Due to ever increasing population of human beings there is shortage of food, clothing and shelter. To procure these basic needs, we have exploited many natural resources causing destruction of the earth’s natural ecosystem.
Now it is our turn to protect the earth as on the same planet the next generations have to survive. We have to hand over the ecosystems of the earth which are in perfect balance to the new generations.
The future generations need a good quality of air, water and land along with all other living organisms.
Due to problems like climate change, global warming, pollution, droughts, etc. the environment is impacted, thus in order to keep sustainability of earth, we have to remember that the earth has not been obtained only as ancestral property but we have to save it for future generations.

Question 3.
Write short notes.
a. Environmental conservation.
Answer:
Due to natural and man-made causes, there are many environmental problems on the earth. These problems affect the existence of various living organisms. In order to save these organisms and maintain the environmental balance, there is need for environmental conservation. If this is not done then there will not be any quality of life for the resident humans. For environmental conservation, the Government has formulated acts and rules. UN has established UNEP for the conservation programs.

The people’s participation in the conservation movement is essential. From school age, the environmental values are inculcated in the young minds. Conservation of environment is the social responsibility of everyone. Judicial use of natural resources conservation also way of environmental conservation.

b. Chipko Movement of Bishnoi.
Answer:
Chipko Movement of Bishnoi or Bishnoi Andolan:
Khejarli or Khejadli is a village in Rajasthan, where Bishnoi community is located. The name of the town is derived from Khejri trees.

The first event of Chipko Movement took place in Khejadli village in 1730 AD. In this village 363 Bishnois, led by Amrita Devi sacrificed their lives for protecting the trees of Khejri trees, which trees are considered as sacred by Bishnoi.

Amrita Devi said, “if a tree is saved even at the cost of one’s head, it’s worth it”. She was killed with the axes that were brought to chop off the trees. The three young daughters Asu, Ratna and Bhagubai also sacrificed their lives for trees.

83 Bishnoi villages came together and villagers sacrificed their lives after hearing about Amrita Devi’s sacrifice. Three hundred and sixty-three Bishnois were killed as they opposed the king. After realizing the mistake, the king ordered stoppage of the felling of trees. Honouring the courage of the Bishnoi community, the ruler of Jodhpur, Maharaja Abhay Singh, apologized. He issued a royal decree to protect trees and wild life.

Chipko movement of 20th century in Uttar Pradesh also followed the same pattern of embracing the trees and saving them from cutting.

c. Biodiversity.
Answer:
Biodiversity means the diverse life forms that inhabit any area. Biodiversity is seen due to variety of life forms and different ecosystems that lodge these organisms. In nature there is biodiversity on the three different levels, viz. genetic diversity, species diversity and ecosystem diversity. This means that there is diversity in the individuals belonging to the same specips due to genetic reasons, there is diversity among the different species of organisms and there is also a diversity in the ecosystems that are present in any region.

Due to development of mankind, the biodiversity is threatened. There are special efforts taken to restore the lost and threatened biodiversity. Some of these are establishing sanctuaries, National Parks, biodiversity hotspots and reserves etc. Certain endangered species are protected by carrying out conservation projects.

d. Sacred Groves.
Answer:
Sacred grove is the green patch of the forest which is conserved by local people in the name of God. It does not belong to forest department. It is like a sanctuary that is conserved by the common people and tribals in the area. It is rich in the biodiversity.

It is conserved as there is a faith that God or deity reside in the sacred grove. Hence in local language, they are known as Deorai. Due to this reason, people do not fell the trees. Also hunting of any wild life is not done here. More than 13000 sacred groves have been reported in India. Most of these are in Western Ghats in Maharashtra, Karnataka and Kerala. Also, in remaining parts of India sacred groves are reported. Role of sacred grove is tremendous in conserving the biodiversity.

e. Disaster and its management.
Answer:

To save human life from disasters. To help them for moving away from the place of disasters by rapid action.
To supply essential commodities to the affected people. This helps to reduce the gravity of disaster. People are given grains, water and clothes and other basic necessities under this objective.
To bring back the conditions of affected people to normalcy.
To rehabilitate the affected and displaced victims.
To think and execute the protective measures in order to develop capability to face the disasters in
future.

Question 4.
How will you justify that overcoming the pollution is a powerful way of environmental management?
(OR)
“Solving the problem of pollution is an effective way of environmental management.” Justify the statement.
Answer:
1. Pollution is created only due to human activities. Air, water, soil, noise, radiation, thermal, light, plastic are different types of pollution.
2. All types of pollution affect environment and particularly threatening the survival of living organisms.
3. Pollution must be controlled in order to have good quality of the environment. E.g. When plastic is thrown anywhere, it causes pollution of the land, it clogs the rain water drains, it affects feeding of the animals. Plastic pollution can be completely stopped by us through proper management of plastic waste. By recycling or reusing, we can overcome the plastic pollution. This would be a powerful way of environmental management.
4. Similarly, when we reduce pollution of different types, we automatically help to regain the environmental health.

Question 5.
Which projects will you run in relation to environmental conservatioh? How?
(OR)
Write six strategies implemented by you for conservation of the environment.
Answer:
Initially, assessment of the environmental problems will be done. The nature and severity of these problems will be understood by detailed study of the same. Then the projects can be undertaken to combat these problems.

1. Tree plantation is one such easier project that can be undertaken to conserve environment. The further nurturing of the tree will also be our responsibility. While selecting the tree, the local and sturdy varieties will be selected. Such trees can survive in polluted environment too and even under the pressure of urbanization.

2. Solid waste management is another very important project that should be undertaken by every society, colony or school. Segregation of waste into dry and wet types and then its proper disposal will be taught to all the people in the neighbouring area.

3. To ban the plastic and make people aware about harmful effects of plastic is another very significant project.

4. Fossil fuels are non-renewable and polluting. Therefore, their use should be reduced as far as possible. Therefore, using bicycle, or walking down for shorter distances or using public transport systems are the better alternatives. The awareness drive about these facts will be taken up as a project.

5. To take care of stray animals, provide shelter, feeding endangered birds like sparrows and allowing them to survive with our support is also one of the essential act to conserve other species.

6. Attempts will be made for bringing awareness among minds of everyone. Such small acts can bring about major shift in the attitude of the people. This will certainly help in the environmental conservation.

Question 6.
Answer the following:
a. Write the factors affecting environment.
Answer:

The biotic and abiotic- factors affect the environment. Among abiotic factors, the physical and chemical factors can alter the conditions of the environment.
Abiotic factors are either natural or man-made.
The various interrelationships between different living organisms can also affect environment.
The natural disasters such as earthquake, forest fires, cyclones, cloud bursting, drought, etc. change the environment.
The human activities such as deforestation, urbanisation, constructions etc. cause permanent damage to the ecosystems. Due to man-made impact, there can be large scale changes in the environment.

b. Human beings have important place in environment.
Answer:

Man came last on the earth during evolution of animals. But due to his intelligence, imagination, critical thinking and memory, he made progress in all fields.
By virtue of these qualities he became the supreme.
All the natural resources on the earth were very rapidly exploited by man.
Under the pretext of technology and. development he made degradation of almost all¬natural ecosystems.
He never obeys the rules of nature.
Phenomena like pollution, urbanization, industrialization and deforestation are exclusively his creations.
Hunting and poaching other animals were his contribution to the extinction of many other animals.
Except man no other organism on the earth can change the ecosystems in such a drastic way. Therefore, it is rightly said that human beings have important place in environment.

c. Write the types and examples of biodiversity.
Answer:
Biodiversity is documented on the following three levels, viz. genetic diversity, species diversity and ecosystem diversity.
1. Genetic Diversity: Diversity seen among the organisms of same species due to genetic differences is called genetic diversity. E.g. The individual human beings are different from each other. No two animals or plants are exactly alike.

2. Species Diversity: The difference between the different species is the species diversity, e.g. All the species of plants, animals and microbes which are seen in any natural environment.

3. Ecosystem Diversity: In one region there may be different ecosystems, such diversity in the ecosystems is called ecosystem diversity. Ecosystems are natural or artificial. Every region shows different types of ecosystems such as aquatic, terrestrial, desert or forest ecosystems. Each ecosystem has its own habitats with resident flora and fauna.

d. How the biodiversity can be conserved?
Answer:
Biodiversity can be conserved by the following ways:

Protection of the rare species of plants and animals.
Creating habitats for the animals and plants by establishing National Parkland Sanctuaries.
Declaration of bioreserves, the areas which are protected through conservation.
Conservation projects for protecting special species.
Conservation of all flora and fauna.
Strict observance of the acts and rules.
Use of traditional knowledge and maintaining record of traditional knowledge.

e. What do we learn from the story of Jadav Molai Payeng? (Board’s Model Activity Sheet)
Answer:
Jadav Molai Payeng is a common man who was just a simple forest worker. But he has conscience about plants and tree plantations. He single-handedly planted thousands of trees. He converted a barren patch of land into forest which is spread over 1360 acres. For these plantations he continuously worked.

He has shown that a single determined person, can establish a new forest! We understand the values of
hard work, sincerity and devotion to the nature through the story of Jadav Molai Payeng. Even a common man can contribute a lot for the conservation and protection of the environment by learning the story of Payeng.

f. Write the names of biodiversity hot spots.
Answer:

In entire world, 34 highly sensitive biodiversity spots are reported.
These hotspots occupied 15.7% area of the Earth.
However, currently about 86% of the sensitive areas are already destroyed.
Now about 2.3% area of the Earth still has such sensitive biodiversity spots.
There are 1,50,000 plant species which are about 50% of the species in the world.
In India, out of 135 species of animals, 85 species are found in the jungles of eastern region.
There are about 1,500 endemic plant species in Western Ghats.
About 50,000 plants species out of the total plants in the world are said to be endemic.

g. Which are the reasons for endangering the many species of plants and animals? How can we save those diversity?
Answer:

The animals and plants species are endangered majorly due to man-made causes.
Some natural disasters like earthquakes, climate change, forest fires, drought and cyclones also affect the living organisms due to lack of food and water.
In man-made causes, hunting and poaching are the main reasons.
Also animal-human conflicts occur due to invasion of human settlements into the habitats of wild animals.
Construction of dams, roads, and colonies destroy the habitats of wild life.
Industrialization, urbanization and population explosion of humans are putting severe pressure on all the existing biodiversity.
In order to save and protect the biodiversity, many scientists and naturalists come together. A stretch of land is protected by declaring it as the sanctuary or a national park by the Government. Even the locals can protect it as a sacred grove.
Various acts and rules have been formulated to protect the organisms. The violators of such rules are punished accordingly.

Question 7.
What are the meanings of the following symbols? Write your role accordingly. (July ’19; Board’s Model Activity Sheet)
(OR)
What do these symbols indicate? Explain your opinion about those symbols.

Answer:
1. The first symbol is for giving the message, “Reduce, reuse and recycle”. This is important mantra for the utilization of natural resources.
The second symbol gives the message about ‘Save water’.
The third symbol advocates the use of solar energy.

2. These symbols inculcate the importance of being eco-friendly. The first symbol is essential to maintain the natural resources by reusing and recycling them. As far as possible, one should reduce the excessive use of resources by preventing consumerism.

3. Water problems persist in many major cities and villages. In villages it results in drought like conditions. It also reflects into loss of agricultural produce. Therefore, the message about saving water or to make judicious use of water should be spread far and wide.

4. The solar energy is the renewable energy option which is very easily available in country like India. By using solar energy, we can replace the polluting and exhaustible fuels. Thereby, pollution will also be reduced.

Due to such symbols, important messages about environment conservation reach, us and we can change ourselves into more eeofriendly persons.

Project: (Do it your self)

Project 1.
Make a presentation on pollution of Gangci and Yamuna Rivers and effects of air pollution on Taimuhal.

Can you recall? (Text Book Page No. 36)

Question 1.
What is ecosystem? Which are its different components?
Answer:
In any environment, there are biotic and abiotic components. There are interactions among these components. All such interactions make an ecosystem.

The different components in the ecosystem are as follows:
Abiotic components : Air, water, soil, sunlight, temperature, humidity, etc.
Biotic components: All the types of living organisms, like bacteria, fungi, plants and animals.

Question 2.
Which are the types of consumers? What are the criteria for their classification?
Answer:
Primary consumers, secondary consumers, tertiary consumers or apex consumers are the different types of consumers. These types are according to the trophic level to which they belong.

Question 3.
What may be the relationship between lake and birds on tree?
Answer:
The birds on the tree depend on the aquatic organisms in the lake for their feeding. Birds stay on the trees which are in the vicinity of the lake, so that it is easier for them to capture fishes, frogs, etc. They must also be using the same lake water for drinking.

Question 4.
What is difference between food chain and food web?
Answer:
In every ecosystem, there are always interactions between producers, consumers and decomposers. This sequence of feeding interactions is called food chain. In every food chain there are links between four to five trophic levels constituting the producers, primary consumers, secondary consumers, tertiary consumers, etc. The links of food chain are in linear sequence. But food web is a complex network of many small food chains. In fact, food web is the collection of many small food chains. Thus, when many food chains are interwoven, they form food web.

Think and Answer! (Text Book Page No. 36)

Question 1.
Write the name and category of each of the component shown in picture.
Answer:
By utilizing the solar energy, the green plants perform photosynthesis. Thus, they are producers of the food chain. This food is consumed by the grasshopper. Thus, it is primary consumer. Frog is secondary consumer as its diet consists of insects like grasshopper. Snake is tertiary consumer as it feeds on frogs, while the hawk is apex consumer as it can kill the snake and feed on it. Last picture in the food chain is of fungi which are acting as decomposers. Few bacteria are shown in the picture, act on all the levels and bring about decomposition.

Question 2.
What is necessary to convert this picture into food web? Why?
Answer:
If this food chain has to be converted into a food web, there should be interactions between the different components. Any living organism can be prey to different predators. Moreover, a predator can also be a prey for other. Frog eats different insects. The same frog can be either eaten by snake or by hawk.

Use your brain power. (Text Book Page No. 40)

Question 1.
Why is it said that pollution control is important?
Answer:
The quantity of pollutants and severity of their effects on the ecosystem have to be taken into consideration constantly. The different methods of pollution control have to be used for checking the hazardous effects of pollution on the living organisms. Especially the impact of pollution on health of human beings is assessed from time to time.

The young children and senior citizens are affected to greater extent by the pollution. If the air and water required for the survival of the people is affected, then exercising the pollution control is to be done immediately. Thus, it is said that pollution control is important.

Enlist and discuss (Text Book Page No. 43)

Question 1.
Find the meaning of given symbols in relation to environment conservation. Make a list of other such symbols.
A.
Answer:
This symbol tells us to keep our wastes carefully. The garbage should not be strewn anywhere. But it should be properly managed. Waste if managed properly can be a wealth.
B.
Answer:
This symbol tells us to save electricity. If electricity is carefully used, we can save our natural resources. This message is given through this picture.
C.
Answer:
Use of bicycle means use of green energy. By riding on a bicycle we save on fuel and use our own muscular energy. It is the best eeofriendly, non polluting vehicle.

Observe and fill the information: (Text Book Page No. 8)

Question 1.
Observe the environment around you. Complete the following flow chart.

Answer:

Complete the Chart: (Text Book Page No. 39)

Question 1.
We have studied the air pollution, water pollution and soil pollution in detail in earlier classes. Based on that, complete the following chart.

Answer:

Complete the Chart: (Text Book Page No. 40)

Question 1.
Now a day, we are observing the environmental degradation everywhere. Complete the flow chart given besides with the help of environment.

Answer:

(Text Book Page No. 43)

Question 1.
Where are such sacred groves in Maharashtra? Make a list and visit with your teachers.
Answer:
Sacred groves: Sacred groves form an important landscape feature in the deforested hill ranges of the Western Ghats. The felling of timber and the killing of animals in sacred groves is not allowed by the locals. It is considered as taboo.

In Maharashtra, sacred groves are found in tribal as well as non-tribal areas. The sacred groves in the western part are called Devrai or Devrahati, which means the abode of the gods. In eastern parts it is called Devegudi by the madiya tribal people.

In Maharashtra 2820 Devrais have been documented. Maruti, Vaghoba, Vira, Bhiroba, Khandoba and Shirkai are some deities to which sacred groves are dedicated.

In the sacred groves, the most commonly found plant species are Portia tree, Casuarina, Silk cotton tree, Indian laurel, Indian Elm, Bead tree, Indian butter tree, Turmeric and Japanese ginger. In Maharashtra, sacred groves are maximum in district of Sindhudurg, (More than 1500 out of total 2820) followed by Ratnagiri, then Pune and in district of Satara.

Choose the correct alternative and write that alphabet against the sub-question number:

Question 1.
Paddy fields are frequently attacked by
(a) goats
(b) birds
(c) grasshoppers
(d) monkeys
Answer:
(c) grasshoppers

Question 2.
Basic functional unit to study the ecology is termed as ……………
(a) environment
(b) niche
(c) ecosystem
(d) food chain
Answer:
(c) ecosystem

Question 3.
As per ……….. trading of rare animals has been completely banned.
(a) clause 48A
(b) clause 49B
(c) clause 49A
(d) all the above
Answer:
(c) clause 49A

Question 4.
(4) The jungle in Kokilamukh of Jorhat district of Assam is well known as ………….
(a) Molai jungle
(b) Rhino jungle
(c) Rhino forest
(d) Payang jungle
Answer:
(a) Molai jungle

Question 5.
Maintaining record of ………. knowledge is very necessary.
(a) modern
(b) mythical
(c) vedic
(d) traditional
Answer:
(d) traditional

Question 6.
………… is world’s largest organization engaged in environmental activities.
(a) Greenpeace
(b) Hariyali
(c) B. N. H. S.
(d) I. I. T.
Answer:
(a) Greenpeace

Question 7.
……….. sanctuary of West Bengal is reserved for tigers.
(a) Gir
(b) Sunderban
(c) Molai
(d) Corbett
Answer:
(b) Sunderban

Question 8.
World Biodiversity Day is celebrated on ……… every year.
(a) 22nd April
(b) 5th June
(c) 16th September
(d) 22nd May
Answer:
(d) 22nd May

Question 9.
Out of the total plant species in the entire world, 50,000 are ……………
(a) extinct
(b) endangered
(c) endemic
(d) rare
Answer:
(c) endemic

Question 10.
Giant squirrel is an ………… species.
(a) indeterminate
(b) rare
(c) endemic
(d) endangered
Answer:
(a) indeterminate

Question 11.
In a food chain, autotrophic plants are present at the ……….. level. (March 2019)
(a) tertiary nutrition
(b) secondary nutrition
(c) producer
(d) apex
Answer:
(c) producer

Question 12.
……….. from Manas sanctuary in Assam is under threat. (Board’s Model Activity Sheet)
(a) one horned rhino
(b) Lion
(c) Musk deer
(d) Giant squirrel/Shekru
Answer:
(a) one horned rhino

Write whether the following statements are true or false, giving suitable explanation for the same:

Question 1.
Only abiotic factors play very important role in the ecosystem.
Answer:
False. (Both abiotic and biotic factors play very important role in the ecosystem. Only abiotic factors will not decide the working of an ecosystem.)

Question 2.
Paddy fields are frequently attacked by frogs.
Answer:
False. (Paddy fields are frequently attacked by grasshoppers. Frogs feed on grasshoppers and control the population of these insects that cause destruction of the crops.)

Question 3.
Environmental pollution is necessary and acceptable change in the surrounding environment.
Answer:
False. (Environmental pollution is never acceptable. It is always harmful to the entire ecosystem and thus never necessary.)

Question 4.
X-rays and radiations from atomic energy plants are natural radiations.
Answer:
False. (X-rays are not present in natural radiations. Infra-red and ultra-violet rays are present in natural radiations.)

Question 5.
The person breaching the Environmental Conservation Act is entitled for either one year imprisonment or fine up to ₹ 5 lakh.
Answer:
False. (The person breaching the Environmental conservation Act is fined upto ₹ 1 lakh. He is also entitled to imprisonment for five years.)

Question 6.
Many people come together to establish arnew forest but a single person, if determined can destroy the entire forest!
Answer:
False. (When anything constructive has to be done even a single man can start such action. In case of ‘Molai jungle’, this statement holds true. But when destructive actions are done, many people come together and cause damage.)

Question 7.
There are clusters of thick forests only in Western Ghats of India.
Answer:
False. (Entire India is rich in biodiversity. Just not in Western Ghats but in entire India one can observe the clusters of thick forests and this is mainly due to suitable tropical climate.)

Question 8.
86 highly sensitive biodiversity spots are reported all over the world.
Answer:
False. (As per the latest information and available data, there are 34 highly sensitive biodiversity spots.)

Question 9.
Flow of nutrients in an ecosystem is unidirectional.
Answer:
False. (Flow of energy in an ecosystem is unidirectional. Flow of nutrients is cyclic.)

Match the columns:

Question 1.

Column I	Column II
(1) Physical, chemical and biological factors together form	(a) Biodiversity
(2) The science of interactions between biotic and abiotic factors	(b) Ecosystem
	(c) Ecology
	(d) Environment

Answer:
(1) Physical, chemical and biological factors together form – Environment.
(2) The science of interactions between biotic and abiotic factors – Ecology.

Question 2.

Column I	Column II
(1) Basic functional unit in the environment	(a) Biodiversity
(2) Different types of living organisms	(b) Ecosystem
	(c) Ecology
	(d) Environment

Answer:
(1) Basic functional unit in the environment – Ecosystem.
(2) Different types of living organisms – Biodiversity.

Question 3.

Rules/Act	Year
(1) Sound Pollution (Control and Prevention) Rule	(a) 1980
(2) Biomedical Waste (Management and Handling) Rule	(b) 2011
	(c) 1998
	(d) 2000

Answer:
(1) Sound Pollution (Control and Prevention) Rule – 2000.
(2) Biomedical Waste (Management and Handling) Rule – 1998.

Question 4.

Rules/Act	Year
(1) Forest Conservation Act	(a) 1980
(2) Environmental Conservation Act	(b) 1986
	(c) 2011
	(d) 2000

Answer:
(1) Forest Conservation Act – 1980.
(2) Environmental Conservation Act – 1986.

Question 5.

Species	Examples
(1) Endangered	(a) Red panda, Musk deer.
(2) Rare	(b) Tiger, Lion.
	(c) Lion tailed monkey, lesser florican.
	(d) Monkey, squirrel

Answer:
(1) Endangered Species – Lion tailed monkey, lesser florican.
(2) Rare Species – Red panda, Musk deer.

Question 6.

Species	Examples
(1) Vulnerable	(a) Giant squirrel (Shekhru)
(2) Indeterminate	(b) Red panda, Musk deer
	(c) Tiger, Lion
	(d) Lesser florican, sparrow

Answer:
(1) Vulnerable Species – Tiger, Lion.
(2) Indeterminate Species – Giant squirrel (Shekhru).

Find the odd one out:

Question 1.
Ash, Carbon dioxide, Lead, Asbestos
Answer:
Carbon dioxide. (All others are solid particulate pollutants.)

Question 2.
Manas sanctuary, Sunderbans sanctuary, The Western Ghats, Tadoba National Park
Answer:
Tadoba National Park. (All others are endangered heritage places of India.)

Question 3.
Lion tailed monkey, White rats, Musk deer, Tiger
Answer:
White rats. (All others are species that are threatened.)

Question 4.
Conservation, Regulation, Pollution, Prohibition
Answer:
Pollution. (All others are ways of environmental protection.)

Question 5.
IPCC, UNEP, IUCN, BNHS
Answer:
BNHS. (All others are international organizations. BNHS is Bombay Natural History Society.)

Find the correlation:

Question 1.
Rare species : Musk deer : : ………… : Lesser florican.
Answer:
Endangered species

Question 2.
Red panda : Rare species : : Giant Squirrel : …………
Answer:
Indeterminate species

Question 3.
Nitrogen, Oxygen : Gaseous cycle : : Soil and Rocks : …………
Answer:
Sedimentary cycle

Question 4.
Manas : One horned Rhino : : Gir : ………..
Answer:
Asiatic lion

Question 5.
Mumbai : Bombay Natural History Society : : TehriGarhwal : ………….
Answer:
Chipko centre.

Answer the following questions in detail:

Question 1.
Answer the following questions:
If frog population in paddy field declines all of a sudden,
(a) What will be the effect on paddy crop?
Answer:
If the population of frog declines, then there will be rise in the population of grasshoppers. The paddy fields will hence be infested with insect pests.

(b) Number of which consumers will decline and which will increase?
Answer:
The food chain if altered, results in imbalance in the ecosystem. ‘Paddy → Grasshoppers → Frog → Snake’, this food chain is natural. When by any reason there is dec1ine in the number of frogs, thus secondary consumer will also decline. Due to this decline, snake which is at tertiary consumer level will also decline. Theprimary consumers i.e. grasshoppers will increase as there is now no check on their population. Due to increase in their population the paddy production will be reduced. Due to reduced number of snakes, rats and other rodents from neighbouring areas would also rise, which are also secondary consumers.

(c) Name the Indian states where paddy is cultivated on a large scale.
Answer:
West Bengal, Uttar Pradesh, Haryana, Punjab, Tamil Nadu, Andhra Pradesh, Bihar, Chhattisgarh, Odisha, Assam and Maharashtra.

Question 2.
What is radioactive pollution? What are its effects?
Answer:
(1) The radiations emitted either through the natural sources or through man-made sources cause radioactive pollution.
(2) The natural radiations is in the form of ultra violet and infrared radiations.
(3) Artificial or man-made radiations are X-rays and radiations from atomic energy plants.
(4) All radiations are highly hazardous for the living organisms. The impact of radiation is also for a very long time.
(5) It has brought about major accidental mishaps at Chernobyl, Windscale, qpd Three Miles Island. These disasters have affected thousands of people.
(6) Some other effects of radiations are as follows – (i) Due to higher radiations of X-rays, cancerous ulceration occurs, (ii) Radiations destroy the body tissues, (iii) Radiations cause mutations and thus genetic changes occur, (iv) There is adverse effect on the vision.

Question 3.
Give one word for “The forest conserved in the name of God.” (Board’s Model Activity Sheet)
Answer:
Deorai.

Give scientific reasons:

Question 1.
Certain scavenging caterpillars, termites and insects found in the dung are important.
Answer:

Scavenging caterpillars and insects are decomposers. They seem to be Worthless due to filthy surrounding in which they thrive.
But they carry out most important task of decomposition of complex organic substances into simple inorganic elements.
This recycling is possible only due to decomposers.
If they are not present, there will be huge accumulation of garbage. Therefore, these living organisms are important.

Question 2.
Destroying trees is to destroy everything.
Answer:

When a single huge tree is felled many living organisms which are dependent on it, are exterminated.
Many insects, fungi, birds, etc. lose their habitat.
Trees take up carbon dioxide from the atmosphere and release oxygen. These natural cycles are also hindered due to loss of trees.
Due to trees there is shade, cooler atmosphere and increase in the rainfall. When such trees are destroyed all the components in the ecosystem are destroyed too.

Question 3.
There is no definite information about indeterminate species.
Answer:

Indeterminate species do not have substantial information about them.
The organisms belonging to such species appear to be endangered due to their some behavioural habits.
They are shy and do not come in open so that they can be observed keenly.
For example, animals like Giant squirrel also do not provide such information.

Question 4.
Tigers from Sunderbans and Rhinos from Manas are under threat.
Answer:

Manas is in the area-of Assam where there are many dams and Indiscriminate use of water.
This area is also flood affected. Therefore, rhinos are under threat.
In Sunderbans, there are also problems such as deforestation, dams, excessive fishing, and dug out trenches.
All of these cause dangers to the tiger population.

Question 5.
There are clusters of thick forests in the Western Ghats of India.
Answer:

There are many sacred groves in the region of Western Ghats of India.
These forests are not conserved by Government Forest Departments but are cared for by the local people, in the name of God.
Due to such faith in the people, the forests are conserved like sanctuaries.
Such many clusters are in Western Ghats of Maharashtra.

Question 6.
We can see biodiversity on three levels.
Answer:

There is biodiversity in the living organisms belonging to the same genus.
This diversity is due to different heredity pattern. This is called genetic biodiversity.
The organisms occupying the same area and belonging to the same species also show diversity due to different species. This is species biodiversity.
The organisms occupying different ecosystems also show differences, which is called ecosystem biodiversity. Therefore, we observe biodiversity on three different levels.

Questions based on diagrams:

Question 1.
What is shown in the picture? Write name and trophic level of each component.

Answer:
In this picture, food chain having rive trophic levels is shown.
(1) Trophic level 1 = Producers : Green plant.
(2) Trophic level 2 = Primary consumer (Herbivore): Grasshopper.
(3) Trophic level 3 = Secondary consumer (Carnivore): Bird.
(4) Trophic level 4 = Tertiary consumer (Carnivore) : Snake.
(5) Trophic level 5 = Top or Apex consumer (Carnivore) : Owl.

Question 2.
Explain the meaning of following symbols A and B and C.
A.

Answer:
The symbol show types of green energy such as solar energy and wind energy. It also expresses that people
should use such sources of energy for their use.

B.

Answer:
This symbol is giving the message “Save water”. Sustainable use of water is necessary for our future.

C.

answer:
The symbols of WWF and BNHS are shown here. BNHS stands for Bombay Natural History Society. This institute works for the conservation and documentation of flora and fauna.

WWF means World Wild Life Fund. Also known as World Wide Life Fund. This International Institute is looking after the welfare of wildlife through different conservation projects. WWF symbol shows Panda while BNHS symbol has Giant Hornbill.

Question 3.
(a) Identify the following symbols and state their significance: (March 2019)

Answer:
(i) This symbol is giving the message “Save water”. Sustainable use of water is necessary for our future.
(ii) Use of bicycle means use of green energy. By riding on a bicycle we save on fuel and use our own muscular energy. It is the best ecofriendly, non polluting vehicle.

(b) How can biodiversity be conserved?
Answer:
Biodiversity can be conserved by the following ways:

Protection of the rare species of plants and animals.
Creating habitats for the animals and plants by establishing National Park and Sanctuaries.
Declaration of bio reserves, the areas which are protected through conservation.
Conservation projects for protecting special species.
Conservation of all flora and fauna.
Strict observance of the acts and rules.
Use of traditional knowledge and maintaining record of traditional knowledge.

Activity based questions:

Question 1.
Questions based on the charts.
Complete the flow chart: (July 2019)

Answer:

Question 2.
Collect more information about locations of these hotspots present in the world. (Textbook page no. 44)
Answer:
Students should collect this information.

Question 3.
Where are such sacred groves in Maharashtra? Make a list and visit with your teachers. (Textbook page no. 43)
Answer:
Sacred groves: Sacred groves form an important landscape feature in the deforested hill ranges of the Western Ghats. The felling of timber and the killing of animals in sacred groves is not allowed by the locals. It is considered as taboo.

In Maharashtra 2820 Devrais have been documented. Maruti, Vaghoba, Vira, Bhiroba, Khandoba and Shirkai are some deities to which sacred groves are dedicated.

Projects: (Do it your self)

Project 1.
Let’s Discuss: (Text Book Page No. 41)
Collect the information about Chipko Movement and discuss between two groups of your class about its importance in present situation.

Project 2.
Collect more information on the organization of Greenpeace. (Text Book Page No. 43)
Answer:
Students are expected to write this answer to this question.

Project 3.
There should be positive attitude of human being towards the environment for welfare of entire living world. For this purpose, following roles are important. You can be a conservator, organizer, guide, plant-friend, etc. Describe about the role you wish to perform and your plans for that role. (Text Book Page No. 42)

Project 4.
Survey the plants and animals in your area. Maintain a record about their characteristics. (Text Book Page No. 45)
Answer:
Students can conduct such surveys with the help of elders.

Project 5.
Internet is my friend! (Collect the information Textbook page no. 41)
(1) Sound Pollution (Control and Prevention) Rule, 2000.
(2) Biomedical Waste (Management and Handling) Rule, 1998.
(3) E-waste (Management and Handling) Rule, 2011.

10th Std Science Part 2 Questions And Answers:

Std 8 History Chapter 14 Questions And Answers Formation of State of Maharashtra Maharashtra Board

February 6, 2025January 5, 2025 by Bhagya

Balbharti Maharashtra State Board Class 8 History Solutions Chapter 14 Formation of State of Maharashtra Notes, Textbook Exercise Important Questions and Answers.

Class 8 History Chapter 14 Formation of State of Maharashtra Questions And Answers Maharashtra Board

Formation of State of Maharashtra Class 8 Questions And Answers Chapter 14 Maharashtra Board

Class 8 History Chapter 14 Formation of State of Maharashtra Textbook Questions and Answers

1. Rewrite the statements by choosing the appropriate options:

Question 1.
The State of …………….. was formed on 1 May, 1960.
(a) Goa
(b) Karnataka
(c) Andhra Pradesh
(d) Maharashtra
Answer:
(d) Maharashtra

Question 2.
…………….. put forth the proposal of Samyukta Maharashtra with Mumbai in the Mumbai Municipal Corporation.
(a) G. T. Madkholkar
(b) Acharya Atre
(c) D. V. Potdar
(d) Shankarrao Dev
Answer:
(b) Acharya Atre

Question 3.
…………….. accepted the responsibility as first Chief Minister of Maharashtra.
(a) Yashwantrao Chavan
(b) Pruthviraj Chavan
(c) Shankarrao Chavan
(d) Vilasrao Deshmukh
Answer:
(a) Yashwantrao Chavan

2. Explain the following statements with reasons:

Question 1.
Samyukta Maharashtra Samiti came to be established.
Answer:

The demand for a state of Marathi speaking people of all regions was put forth in the Nagpur Pact in 1953.
There was no positive response from the Central Government for formation of Samyukta Maharashtra with Mumbai.
The agitation was made severe through strikes, demonstrations, rallies, etc. which were organised from time to time.
As the issue of the demand of Marathi speaking people started becoming complicated, discontent spread throughout the state.
A meeting was held under the leadership of Keshavrao Jedhe on 6 February, 1956 at Tilak Smarak Mandir in Pune and the Samyukta Maharashtra Samiti was formed.

Question 2.
The role of newspapers was important in Samyukta Maharashtra Movement.
Answer:

The role of newspapers was equally important in Samyukta Maharashtra Movement. They worked to awaken the people.
Navyug, Prabhat, Navakal, Sakai, Prabodhan, Kesari are newspapers which played important role.
The ‘Maratha’ newspaper by Acharya Atre had a significant role in Samyukta Maharashtra movement.
Balasaheb Thackeray took pen name ‘Mavla’ and drew caricatures in ‘Navyug’.
Lokshahir Annabhau Sathe, Shahir Amar Sheikh and Shahir D. N. Gavankar aroused public awakening on a large scale through their writings.

3. Write short notes:

Question 1.
Samyukta Maharashtra Parishad:
Answer:

On 12 May 1946, a resolution was passed regarding Samyukta Maharashtra in the Sahitya Sammelan at Belgaon.
On this background, Maharashtra Ekikaran Parishad was convened under the leadership of Shankarrao Dev at Mumbai on 28 July.
A resolution was passed that all Marathi speaking regions should be united in one state.
It should include the regions of Mumbai, Central provinces Marathwada and Gomantak.

Question 2.
Contribution of Samyukta Maharashtra Samiti:
Answer:
Samyukta Maharashtra Samiti f contributed in the following way to form Samyukta Maharashtra.
1. Samyukta Maharashtra movement spread throughout the state and reached in rural areas.
2. Common people also joined the movement spontaneously.
3. When it was clear that Mumbai will not be included in Maharashtra, Samiti held demonstrations to protest and arouse public agitation.
4. The grand success of Samyukta Maharashtra Samiti in Lok Sabha, Vidhan Sabha and Mumbai Municipal Corporation in 1957 made it clear that the voters were in favour of Samyukta Maharashtra.
5. The agitations led by Samyukta Maharashtra Samiti during the visit of Prime Minister Pandit Jawaharlal Nehru made the approach of Central Government favourable in the formation of Maharashtra state.

4. Complete the following diagram.

Question 1.
Maharashtra Board Class 8 History Solutions Chapter 14 Formation of State of Maharashtra 1
Answer:

Do you Know?

Maharashtra Board Class 8 History Solutions Chapter 14 Formation of State of Maharashtra 3

Contribution of Marathi newspapers and Shahirs: In this movement the role of newspapers was important. Prabodhan, Kesari, Sakal, Navakal, Navyug, Prabhat many such newspapers worked for awakening of the people. Acharya Atre started the ‘Maratha’ newspaper which played an important role in Samyukta Maharashtra Movement.

Balasaheb Thackeray took up the pen name ‘Mavia’ and drew caricatures to make the movement comprehensive. Lokshahir Annabhau Sathe, Shahir Amar Sheikh and Shahir D.N.Gavankar through their writings aroused public awakening on a large scale.

Project:

Collect information about the personalities who greatly contributed to the formation of Maharashtra and prepare a project based on it with the help of your teachers.

Class 8 History Chapter 14 Formation of State of Maharashtra Additional Important Questions and Answers

Rewrite the statements by choosing the appropriate options:

Question 1.
………………… organised rallies to protest against the report of JVP Committee.
(a) Sane Guruji
(b) P. K. Atre
(c) Senapati Bapat
(d) Prabodhankar Thackeray
Answer:
(c) Senapati Bapat

Question 2.
…………….. established Dar Commission for forming linguistic province.
(a) Morarji Desai
(b) Pandit Jawaharlal Nehru
(c) Dr. Rajendra Prasad
(d) Yashwantrao Chavan
Answer:
(c) Dr. Rajendra Prasad

Question 3.
According to 1953 Pact, Assembly session would be held once in a year at …………….
(a) Pune
(b) Mumbai
(c) Nagpur
(d) Aurangabad
Answer:
(c) Nagpur

Question 4.
Police used lathi charge and tear …………….. gas on the March led by
(a) Bhai Madhavrao Bagal
(b) Comrade Shripad Amrut Dange
(c) S.M. Joshi
(d) Senapati Bapat
Answer:
(d) Senapati Bapat

Question 5.
Acharya Atre started the newspaper …………….. which played an important role in Samyukta Maharashtra Movement.
(a) Navyug
(b) Prabodhan
(c) Maratha
(d) Navakal
Answer:
(c) Maratha

Name the following:

Question 1.
Demanded reconstruction of a state based on language in 1915.
Answer:
Lokmanya Tilak

Question 2.
Commission which advocated bilingual Mumbai.
Answer:
‘Commission for Reconstruction of States’

Question 3.
Samiti established at Tilak Smarak Mandir, Pune.
Answer:
Samyukta Maharashtra Samiti

Question 4.
The Act passed by the Parliament in April 1960.
Answer:
Mumbai Reorganisation Act.

Answer the following questions in one sentence:

Question 1.
What was the appeal made by Shankarrao Dev in the meeting held on Kamgar Maidan?
Answer:
Shankarrao Dev appealed to the people in the following words, “We will oppose the separation of Mumbai from Maharashtra up to our last breath.”

Question 2.
What was the suggestion given by the Commission for Reconstruction of States?
Answer:
The Commission for Reconstruction of States suggested creation of bilingual Mumbai State.

Question 3.
What was the resolution proposed by S. M. Joshi on 7 November, 1955 at the meeting of labourers?
Answer:
At the meeting of the labourers on 7 November, 1955 S. M. Joshi proposed a resolution that Samyukta Maharashtra should be created with Mumbai and Vidarbha.

Question 4.
Where was the memorial of 106 martyrs erected? What is it called?
Answer:
The memorial of 106 martyrs was erected in Mumbai near Flora Fountain. It is called ‘Flutatma Smarak.’

Question 5.
Who played an important role in establishing Samyukta Maharashtra Samiti?
Answer:
Acharya P K. Atre, Madhu Dandavate, Prabodhankar Keshav Thackeray, Y. K. Souni played important role in establishing Samyukta Maharashtra Samiti.

Question 6.
Name the lokshahirs who aroused awakening among people during Samyukta Maharashtra Movement.
Answer:
Lokshahirs Annabhau Sathe, Shahir Amar Sheikh and Shahir D. N. Gavankar aroused public awakening among the people during Samyukta Maharashtra Movement.

Do as Directed:

Complete the following diagram:

Question 1.
Maharashtra Board Class 8 History Solutions Chapter 14 Formation of State of Maharashtra 4
Answer:

Question 2.
Maharashtra Board Class 8 History Solutions Chapter 14 Formation of State of Maharashtra 6
Answer:

Complete the table:

Question 1.

Foundation year	Name of the Commission/Samiti	Name of the President
1. 28 July	……………………………………….	Shankarrao Dev
2. …………………………	Dar Commission	Justice S. R. Dar
3. 29 December, 1943	………………………………………..	Justice Fazal Ali
4. 6 February, 1956	Samyukta Maharashtra Samiti	…………………………….

Answer:

Foundation year	Name of the Commission/Samiti	Name of the President
1. 28 July	Maharashtra Ekikaran Parishad	Shankarrao Dev
2. 17 June, 1947	Dar Commission	Justice S. R. Dar
3. 29 December, 1943	Commission for Reconstruction of States	Justice Fazal Ali
4. 6 February, 1956	Samyukta Maharashtra Samiti	Comrade Shripad Amrut Dange

Write short notes:

Question 1.
Dar Commission:
Answer:

The President of Constituent Assembly, Dr. Rajendra Prasad established the Dar Commission on 17 June, 1947.
The Commission started the work under the leadership of Justice S. K. Dar to form states on linguistic basis.
On 10 December, 1948, the report of Dar Commission was published but the issue remained unsolved.

Question 2.
Commission for Reconstruction of States:
Answer:

Indian Government appointed a ‘Commission for Reconstruction of States’ on 29 December, 1953.
It was formed under the Chairmanship of Justice Fazal Ali.
In the proposal presented by the commission on 10 October, 1955, a creation of bilingual Mumbai State was advocated.

Answer the following questions in brief:

Question 1.
What started the demand for an independent state of Marathi speaking people?
Answer:

The demand for an independent Marathi speaking state started before independence.
N. C. Kelkar presented the idea that the entire Marathi speaking population should be under one dominion.
In 1915, Lokmanya Tilak demanded the reconstruction of a state based on language.
An important resolution regarding Samyukta Maharashtra was passed in the Sahitya Sammelan at Belgaon. It began the movement to form Independent state of Marathi speaking people.

Question 2.
Write information on the workers meeting held on 7 November, 1955.
Answer:

The struggle of Marathi speaking people for formation of Maharashtra with Mumbai had started.
On 7 November, 1955 a meeting of labourers was held.
Labour Organisation or Communists, Praja Socialists, Socialists, Peasants and Workers Party, Janasangh, etc. participated in the meeting.
Comrade Shripad Amrut Dange was the President of this meeting.
S. M. Joshi proposed a resolution to create a Samyukta Maharashtra with Mumbai and Vidarbha.

Question 3.
What were the provisions in the Nagpur Pact?
Answer:
The following provisions were made in the Nagpur Pact:

Samyukta Maharashtra should be formed including Western Maharashtra 8 and Vidarbha along with Marathwada.
Assurance was given regarding equitable financial provisions for development.
Ample finance will be provided for technical and vocational education.
Government services will be provided in accordance with the population in the region.
Once in a year an Assembly session will be held at Nagpur.

Question 4.
What happened on the day a grand march was taken to Vidhan Sabha?
Answer:

For the formation of Samyukta Maharashtra, a grand march was taken to the Vidhan Sabha led by Senapati Bapat.
The government declared a ban.
The police started lathi charge and used tear gas on the protestors who broke the ban.
On the same evening, Comrade Shripad Dange guided a mob of fifty thousand on Kamgar Maidan.
To give impetus to the Samyukta Maharashtra Movement, it was further decided to hold one day strike on 21 November, 1955.

Question 5.
Which events took place in the final stages of establishment of Maharashtra state?
Answer:
The following events took place in the final stages of establishment of Maharashtra state:

Due to agitation of Samyukta Maharashtra Movement, central government gave consent to the formation of two linguistic states.
The Congress President, Indira Gandhi also supported the Samyukta Maharashtra Movement.
In April 1960, the Parliament passed the Mumbai Reorganisation Act.
According to this act, Maharashtra State was formed on 1st May, 1960.
Pandit Nehru on the occasion of Labour Day made a formal announcement of the formation of Maharashtra State at a special ceremony at Raj Bhavan.
Yashwantrao Chavan accepted the responsibility of first Chief Minister of Maharashtra.

Explain the following statements with reasons:

Question 1.
Severe response was seen 9, throughout Maharashtra against JVP Committee report.
Answer:

The Congress appointed a three ministers committee on 29 December, 1948 to study the conditions of creating linguistic provinces.
The report suggested that Congress accepted the concept of linguistic state in principle but the time was not proper for it.
Due to this, severe response of the people was seen throughout Maharashtra against JVP Committee report.

Answer the following questions in detail:

Question 1.
How did the Central Government favour Maharashtra’s movement under the leadership of Samyukta Maharashtra Samiti?
Answer:

Pandit Jawaharlal Nehru was going to unveil statue of Chhatrapati Shivaji Maharaj mounted on a horse on Pratapgad on 30 November, 1957.
Under the leadership of Bhai Madhavrao Bagal, Samyukta Maharashtra Samiti held huge demonstrations.
Leaders like S. M. Joshi, N. G. Gore, Jayantrao Tilak, R K. Atre participated in the protest at Pasarni Ghat and Poladpur.
Pandit Nehru became aware of sentiments of the Marathi speaking people.
The Congress President Indira Gandhi supported the Samyukta Maharashtra Movement.
Finally, the Central government gave consent for formation of two states-Gujarat and Maharashtra from former Mumbai (Bombay) state

Question 2.
Observe the given picture and identify. Write about his contribution in Samyukta Maharashtra.
Maharashtra Board Class 8 History Solutions Chapter 14 Formation of State of Maharashtra 8
Answer:

This picture is of Acharya R K. Atre. He made important contribution to Samyukta Maharashtra Movement.
He played important role in formation of Samyukta Maharashtra Samiti.
He presented and supported the pro- united Maharashtra Movement through his newspaper ‘Maratha’.
He was in the forefront of the demonstrations at Pasarni Ghat and Poladpur during the visit of Prime Minister Pandit Nehru at Pratapgad.

Question 3.
What are the advantages and disadvantages of linguistic reorganisation of states?
Answer:
Advantages:

The feeling of unity is very strong among the people speaking common language.
It guarantees social security.
It facilitates communication between people.
It helps in achieving linguistic and cultural unity.

Disadvantages:

Linguistic reorganisation may narrow perspective of the people.
Excessive pride in one’s language creates hatred towards other language.
Learning other languages and enjoying the literature never takes places.
It creates hurdles in social and cultural development.

8th Std History Questions And Answers:

Disaster Management Class 10 Questions And Answers Maharashtra Board

January 6, 2025January 5, 2025 by Bhagya

Balbharti Maharashtra State Board Class 10 Science Solutions Part 2 Chapter 10 Disaster Management Notes, Textbook Exercise Important Questions and Answers.

Std 10 Science Part 2 Chapter 10 Disaster Management Question Answer Maharashtra Board

Class 10 Science Part 2 Chapter 10 Disaster Management Question Answer Maharashtra Board

Question 1.
Complete the table.

Answer:

Question 2.
Write notes.
a. Disaster Management Authority.
Answer:
Disaster Management Authority is the body that works at the level of government from national level to village level. This work is basically about management of any disaster and tackling the problems of the affected people. At National level there is National Disaster Management Authority for which the Prime Minister is the chairman. For every state there is State Disaster Management Authority, where the chief minister of every state is the chairman. Under the state level, there are district level units where district collector is responsible for disaster management and implementation of rehabilitation schemes. Below district level authority there are Taluka and then Village Disaster Management Committees.

The Tahsildar is the chairman for Taluka level while the Sarpanch of the village is responsible for management of disasters at village level. Collector of each district helps in planning, coordinating and controlling the implementation of rehabilitation programme and also gives essential instructions and reviews the entire system.

b. Nature of disaster management.
Answer:
Disaster management involves either prevention of disasters (Pre-disaster management) or creating preparedness to face them (Post-disaster management). The action plans are prepared for managing disasters. This is done after studying the different aspects such as preventive measures, rehabilitation and reconstruction plans. The disasters are tackled by executing action plans in the following steps: Preparation, redemption, preparedness, action during actual disaster, response, resurgence and restoration. At every level there are other voluntary organizations and Government meteorological institutions for their help.

c. Mock drill.
Answer:

Mock drill is the practice to check whether there is preparedness for dealing with the sudden attack of disaster.
For this purpose, virtual or apparent situations that simulate the disaster are created.
The reaction time for any type of disaster is checked by such activity. In the presence of trained personnel, the execution of the rescue plans are observed.
People also understand their responsibilities at the time of actual disaster.
The experts also check execution of plan designed for disaster redressal.
By such mock drills, the efficacy of the system can be understood. In future, when actual calamity strikes, there is already preparation for disaster redressal. Therefore, mock drill is useful.

d. Disaster Management Act, 2005.
Answer:
Government of India has made Disaster Management Act in 2005. The affected people are given all necessary help as per this act. With the humanitarian view, people are rehabilitated and helped them to come back to normalcy after the disaster.

As per this Act, National Disaster Response Force has been established. This force consists of 12 divisions in entire India which are attached with Indian Army. The headquarter is located in Delhi, but the action is taken all over the country with the help of army. As per the Act, in Maharashtra National Disaster Response Force is in action through State Reserve Polioe Force. The personnel of this force are trained accordingly, and they take part in the rescue work during different disasters.

Question 3.
Answer the following questions.
a. Explain the role of district disaster control unit after occurrence of any disaster.
Answer:
(1) District control unit looks after the ; disaster management of the district.
(2) It is immediately formed either after the impact of disaster or if warning is given about some upcoming disaster.

District-wise Disaster Control Unit performs following role:

The review of various aspects of disasters is done.
Through the disaster control unit there is continuous contact established with various agencies like army, air force, navy, telecommunication department, paramilitary forces, etc. for obtaining help.
The unit also coordinates with various voluntary organizations for their help in disaster management.

b. Give the reasons for increase in human disasters after the World War-II.
Answer:

After Second World War, the feelings of peace and brotherhood among the global citizens were lost. The geographic, religious, racial and ethnic differences sprang up tremendously.
Atrocities that Nazi has performed made deep impact on the minds of people. Terrorism, abduction, robberies and social unrest increased in almost all the countries.
The financial losses had incurred in the World War II. The misuse of science and technology was done to retrieve these deficits.
At the end of World War II, the atomic bombs were dropped in Japan. This has created health problems in the entire world.
Social inequality, economic disparity, racial and religious differences were some adversaries that created unrest in the country.
Later, the neighbouring nations kept on fighting. The geographical boundaries were changed. People always had feelings of insecurity. The terrorism flourished. All such instances gave rise to man-made disasters.

c. What are the objectives of disaster management?
(OR)
State any four objectives of disaster management. (March ’19)
Answer:
Objectives of disaster management:

To save human life from disasters. To help them for moving away from the place of disasters by rapid action.
To supply essential commodities to the affected people. This helps to reduce the gravity of disaster. People are given grains, water and clothes and other basic necessities under this objective.
To bring back the conditions of affected people to normalcy.
To rehabilitate the affected and displaced victims.
To think and execute the protective measures in order to develop capability to face the disasters in future.

d. Why is it essential to get the training of first aid? (July ’19)
Answer:
When there is a disaster, we need to immediately help the victim. Till the medical help arrives, one should be in position to treat the injured and save his or her life. In such cases; knowing first- aid is essential. Such kind of a need may arise in case of our parents, our siblings at home or with friends in school. Those who are injured should be treated at once. If we know about techniques of first aid, we can save such person before the medical help arrives. Therefore, it is essential to get the training of the first aid.

e. Which different methods are used for transportation of patients? Why?
Answer:
For the transportation of patients following methods are used:

Cradle method: This method is used for children and persons with less weight.
Carrying piggy back: This method is useful in carrying the unconscious persons.
Human crutch method: If one leg of the person is injured, then the victim is supported with minimum load on the other leg. This is called human crutch method.
Pulling or lifting method: For carrying an unconscious person for a short distance this method is used.
Carrying on four-hand chair: This method is used when the support is needed for a part below waist region.
Carrying on two-hand chair: Patients that cannot use their hands but can hold their body upright, are carried by such method.
Stretcher: By making temporary stretcher in case of emergency, the unconscious patient can be moved. Such temporary stretchers are made by using bamboos, blanket, etc.

Question 4.
On the basis of the structure of disaster management authority, form the same for your school.
Answer:

Question 5.
Write down the reasons, effects and remedial measures taken for any two disasters experienced by you.
Answer:
Students are expected to write the answer based on their own experiences.

Question 6.
Which different aspects of disaster management would you check for your school? Why?
Answer:
For the pre-disaster management at school following aspects would be inspected.

Are the telephones 6f the school working properly?
Is there a first-aid box in each class?
Are there any basic medicines in the school?
Is the team ready for rescue of smaller children from lower classes?
Has monitor or prefect participated in a mock drill? Does he/she know about first aid?
Is the contact of parent representative available in emergency situations?
Is the Medical Officer/Doctor present on the school campus?
Is there enough drinking water and some dry snacks available in the school?
Are the staircases and corridors suitable for quick evacuation of the children?

Question 7.
Identify the type of disaster.
a. Terrorism.
Answer:
Man-made, intentional.
Due to the activities of terrorism, many innocent lives are lost. Many are seriously injured. Some become crippled for their entire life. Buildings, monuments, vehicles everything is completely destroyed. There is rift between different religions or sects. The peaceful atmosphere is disturbed. The entire society is under the constant fear of insecurity.

b. Soil erosion.
Answer:
Natural, geophysical, geological.
When the upper fertile layer of soil is lost, it becomes barren. The trees are uprooted. The fertility of the area is lost. The land becomes unsuitable for cultivation or farming. Due to wind, flowing water or grazing animals the naturally occurring soil erosion becomes hazardous for the environment.

c. Hepatitis.
Answer:
Natural, biological, animal-origin.
Hepatitis is a viral disease which spreads through the contaminated food and water. The outburst of epidemic of hepatitis is difficult to control. As in big cities the quality of road side food is often consumed, the spread of hepatitis is. fast. People suffer due to hepatitis.

d. Forest fire.
Answer:
Natural, biological, plant-origin.
Due to heat and wind, the dry grass and the shrubs catch fire in the forests, resulting in forest fires. Such rapidly spreading forest fire can finish the biodiversity within a very short span of time. It is difficult to extinguish the naturally lit forest fires. Many trees and other vegetation, animals and birds along with their habitats are destroyed due to forest fire. The smoke emanating causes the air pollution.

e. Famine.
Answer:
Natural, climatic.
Due to famine there is severe water scarcity. In absence of water, the fields and farms become barren as the crops cannot grow without water. There is shortage of food grains. The cattle dies due to want of water and grass. Local people have to migrate in search of food, water and shelter.

f. Theft.
Answer:
Man-made, intentional.
Theft causes economic loss for the one whose money or valuables are looted. The person who suffers the loss also undergo mental and emotional shock. Sometimes the thief may also cause physical harm. It may cost on life too.

Question 8.
Some symbols are given below. Explain those symbols. Which disasters may occur if those symbols are ignored?

Answer:
The above signs are warning symbols which should never be ignored.
The meaning of each is given below. They are giving warnings about explosive, inflammable, oxidizing, compressed gas, corrosive, toxic, irritant, environmentally hazardous and health hazard.

(1) Explosive: Some materials are explosive. While handling such materials care should be taken. We should not take anything that would cause fire leading to explosion. If explosion occurs, there would be a major disaster causing great loss of life and property. Thus if this sign is seen, great care has to be taken.

(2) Inflammable: Similar to explosive substances, the inflammable materials can also catch fire easily. Therefore, to warn people such sign is given on materials that can cause hazard by burning.

(3) Oxidizing: Some chemical substances are oxidizing. They carry out chemical reactions with a rapid speed. E.g. If potassium permanganate falls on the cloth, it starts the reaction on its C-C bonds. Due to such property of carrying out reactions, the cloths may catch fire. Therefore, oxidizing substances should be handled with care.

(4) Compressed: Compressed substances are filled under pressure in some container. If mishandled, they can come out of the container by bursting it open. This can cause some injuries.

(5) Corrosive: The corrosive substances are very reactive. The mere touch of corrosive substances can cause destruction of skin, eyes, respiratory passages, digestive organs, etc. rapidly. Just touching or smelling of such substances can cause major injury and thus warning sign of corrosive substance should never be ignored.

(6) Toxic: To taste a toxic substance or even to smell it, can lead to death. The packing of these substances are therefore marked as dangerous. They should be avoided as far as possible.

(7) Irritant: When skin or any delicate part of the body comes in contact with the irritant substance, it can cause harmful reaction. Especially, eyes, nasal mucosa and skin are affected by contact with corrosive substances.

(8) Environmentally hazardous: Many sub¬stances cause harm to the environment due to their toxicity. Air, water or soil can be polluted due to such pollutants. When environment is affected, ultimately these hazardous effects come back to human species. Therefore, such substances should be carefully used. Their use should be judicious and controlled.

(9) Health hazard: The substances that can cause hazard to our health should always be distanced from us. Such substances should not be kept in proximity. As far as possible they should be kept away and handled with great care if needed for any work. Materials marked with health hazard can cause severe toxicity.

Question 9.
Explain that why is it said like that?
a. Mock drill is useful.
Answer:

Mock drill is the practice to check whether there is preparedness for dealing with the sudden attack of disaster.
For this purpose, virtual or apparent situations that simulate the disaster are created.
The reaction time for any type of disaster is checked by such activity. In the presence of trained personnel, the execution of the rescue plans are observed.
People also understand their responsibilities at the time of actual disaster.
The experts also check execution of plan designed for disaster redressal.
By such mock drills, the efficacy of the system can be understood. In future, when actual calamity strikes, there is already preparation for disaster redressal. Therefore, mock drill is useful.

b. Effective disaster management makes us well prepared for future.
Answer:

Disaster can strike any time. The sudden disasters can be man-made with some bad intentions or may be accidental.
When natural calamity strikes suddenly with a huge impact, large scale devastation of property and general environment degradation occurs along with substantial mortality of people and animals.
Therefore, it is most appropriate to have the preparedness to reduce the impact of any future disasters.
We cannot control the onset of the natural disaster, but we can definitely reduce the harsh effects of the disaster by following disaster management plan.

Question 10.
Complete the following chart.

Answer:

Question 11.
Following are the pictures of some disasters. How will be your pre and post-disaster management in case you face any of those disasters?

Answer:
In the pictures given, following disasters are shown:
(1) Two groups of children are fighting with each other.
(2) There is gas leakage from the LPG cylinder.
(3) There is heavy downpour due to cloud bursting which has led to waterlogging in the town.
(4) There is cyclone causing a tornado. (Commonly called a twister)

Projects:

Project 1.
Demonstrate the activities shown on page no. 106 of Std. IX Science and Technology textbook in front of the students of other classes. Make a video clip and send it to others.

Project 2.
Form a group of students from your school to demonstrate the mock drill and demonstrate it in the school

Can you recall? (Text Book Page No. 109)

Question 1.
What is disaster?
Answer:
Disaster is the incidence that occurs suddenly causing heavy damage to life and property. The disaster can be man-made or due to natural reason.

Question 2.
Which disasters have you experienced in your area?
Answer:
On September 2019, there was a heavy downpour in Pune. This disaster has been experienced recently.
On 26th November 2008 there was attack at several places by the Pakistani terrorists. The stories about the deaths and damage caused by this disaster were seen in films and learnt about this from our elders.

Question 3.
What are the effects of that disaster on local and surrounding conditions?
Answer:
Due to a heavy downpour in Pune, there was waterlogging in all the shallow areas. All the transport systems collapsed on that day. Large trees fell down injuring the people. The water logging caused condition like floods. Schools, colleges and offices were shut down. People were caught in troublesome situation.

On 26th November 2008 many innocent people lost their lives. There was tremendous damage caused to some of the important places like Taj Palace Hotel and Chabad house.

Use your brain power: (Text Book Page No. 111)

Question 1.
Depending upon information given on page 111, explain the various effects of the disaster of railway accident.
Answer:
The effects of disastrous railway accident:
The effect will be dependent upon the nature of the accident that has occurred. Whether, it is a collapse of bridge or due to derailment of the train, or due to collision of two moving trains, whether it is due to failure in signaling system, due to land slide or due to obstacle in the tunnel, that has to be understood. The impact of such railway accident will be dependent on the way that accident has occurred. Based on this impact the effects will take place.

(1) Environmental	The entire surroundings will show destruction.
(2) Administrative/ Managerial	The railway department will have stress and the time table will collapse. The regular use of tracks will hamper, resulting into delay in railway traffic.
(3) Political	Ministry of railways is considered to be responsible for the accident. Sometimes the Railway Minister resigns.
(4) Medical	The passengers commuting in the train die or suffer from serious injuries.
(5) Economic	The railways suffer huge financial loss.
(6) Social	The railway traffic is disturbed. Passengers are troubled as they get held up at some place.

Observe/Discuss:
Let’s Discuss: (Text Book Page No. 110)
Question 1.
observe the images on textbook page no. 110. whether the places of disasters are known to you? Discuss the emfects of these disasters on public lire. How people could lave been saved from these disasters? Discuss with your friends in the classroom.
Answer:
Students should discuss the disasters given in the pictures by themselves after collecting the information.

Observe: (Text Book Page No. 114)

Question 1.
Observe the disaster cycle given below and explain each aspect of the disaster of earthquake.
Answer:
The main aspects of disaster cycle to tackle disaster of earthquake are as follows:
(1) Preparation : With the help of seismograph, the warning about forthcoming earthquake can be obtained these days. The intensity of the earthquake is also predicted with the help of technology. If the estimate of the Richter scale is on the higher sides, there would be more preparatory measures taken to tackle the forthcoming problem of earthquake.

(2) Redemption: Once this information is obtained the possible impact of the earthquake on the houses, buildings, people can be studied by the geological experts. The meetings of the Disaster Management Authority will be organized for same.

(3) Preparedness: What the general public should do and what action the reserved forces should take, will be decided in case of actual incidence of the earthquake. The schemes and plans will be made ready in this direction.

(4) Impact of Earthquake: In case of disaster of earthquake, people will be helped to safety. The trapped people will be rescued. First aid and other necessary help will be provided. The data about the losses and the intensity of this disaster will be noted and reported for the further process.

(5) Response: In this phase the response of the people as well as the action of Government can be well studied. The response should be quick and positive. The maximum lives and property should be saved by such responses. The disaster of earthquake should be managed with positivity and through help given to the sufferers.

(6) Resurgence: Earthquakes can destroy the entire households or even entire community. Such homeless people should be given the place to stay. Resurgence is important phase for the national welfare. If the citizens of India are cared for, the nation too will progress.

(7) Restoration: The earthquake victims should be settled by providing them with new settlements. Sometimes, entire village is to be settled. E.g. In Latur or Kutch, there twas very large scale devastation. But Government of India as well as some NGOs helped to reconstruct the houses. In such earthquake-prone areas, houses are built in specific pattern to withstand any possible future calamities.

Observe: (Text Book Page No. 117)

Question 1.
Give the reference of following pictures and explain importance of each of those in disaster management. Which are other such activities ?

Answer:
The actions shown in the above pictures are as follows:
(a) The patient is made to lie on the stretcher. He must be unconscious and injured to greater extent, so that he cannot move by himself.
(b) The patient is helped by giving artificial respiration. Probably the victim is suffocated and needs oxygen supply.
(c) and (d) The patient is being picked up. Most probably the patient is unconscious.
The unconscious person who cannot move by himself is carried by these two methods. In method ‘c’, the weight of the patient is less and hence he can be lifted as shown in the picture. In picture ‘d’ the victim has to be lifted in other way, may be due to his greater body weight.
(e) The patient is carried on the back as in ‘carrying piggy back’ position. He too is unconscious and needs to be shifted for medical treatment.
(f) The patient in this picture is carried by ‘human crutch method’. When victim’s one leg is injured, he cannot walk without support. Hence, he needs to be carried in such a way.

In all the above methods, the injured person at the time of disaster is transported to hospital or dispensary for further medical help. The primary first-aid is given to the victim. Now the volunteer is taking him for further treatment. Such rescue activities depend upon the type of disaster and the extent of the injury. Hence the methods will be of different nature.

Let’s Think: (Text Book Page No. 111)

Question 1.
What will be the effect on yourself and surrounding, if any accident-like disaster occurs during the sports on playground or in school?
Answer:
When in school, there is an accident, first of all we get scared. But with caring help of the teacher, we will give the first aid to the injured friends by using first aid kit. If the injury is serious, we will take him to the medical centre of the school. While playing or during sports event, children flock around and make unnecessary crowding. In case of such accident, first of all the crowd will have to be dispersed. If there is major disaster, one should not fumble but manage the disaster in a wise way with the help of teachers.

Let’s Think: (Text Book Page No. 112)

Question 1.
Explain the nature and scope of the disaster of flood with the help of six points given on text book page no. 112.
Answer:
The nature and the scope of the disaster of flood can be described according to the six points:
(1) Pre-disaster phase: Due to Indian Meteorological Department the warning predictions are received before any climatic disaster strikes. If the scope of the flood is predicted to be high, then the people who may be affected by the calamity are relocated to a safer area.

(2) Warning phase: In the warning phase the Government warns the general public about the forthcoming disaster of floods through mass media like radio, television, newspapers, etc. In recent times, even the cellphone messages are sent to people for warning them. The people living in coastal areas will be worst affected and hence such people are given greater care and they are immediately made to leave their houses. They are taken to the safe places.

(3) Emergency phase: When the flood waters actually start rising up, the low-lying areas are submerged. Houses, roads and shops everything goes under water. The rescue operations are carried out by army men from National Disaster Rescue Force. They take every possible effort to rescue the trapped people. The emergency continues till the water does not recede. Later after the water starts receding, people who had been taken to places on heights, start coming back. During this phase, search, rescue operations, medical treatment, and first aid are all the aspects on which the attention is focussed.

(4) Rehabilitation phase: The people affected due to floods are given emotional and financial support. The fields, farms, houses or cattle-shed are under water. Such people are given transient accommodations. Many cattle and other animals die by drowning. Their rotting carcasses have to be disposed as soon as possible because the decaying process spreads epidemics of diseases. People are given vaccinations to protect them from diseases of such kind. Special care of young children and senior citizens is taken during this period. Supply of food and drinking water is also very important task during this time.

(5) Recovery phase: During recovery phase, the life comes gradually back to normalcy. The removal of dead, decaying material and the debris is the first priority. The water connections and electricity is restored back. Various NGOs or Government organizations provide help of various kind to the affected people. This help is to be distributed to those who are in real need. This work is also done by Disaster Management Department.

(6) Reconstruction phase: The houses and building that collapse due to floods are built back. Agricultural activities start again. Roads and water supply is once again normalized. Schools and colleges start once again. Thus, the once flood affected area comes back to routine functioning again.

Let’s Think: (Text Book Page No. 117)

Question 1.
Following are some pictures of disasters. Which precautions would you take during those disasters?

Answer:
The pictures shown above are showing earthquake, fire and snake bite respectively.
In the above disasters, the initial precautions to be taken are as follows:
(1) Earthquake: In case of earthquake, one should immediately come out of house and stand in the open ground. If this is not possible, one has to go below table or any other cover. During collapse of the building, there should not be a head injury. This precaution is basically for prevention of dangerous injuries and saving our life. Switch off the power supply. If in journey, stay inside the vehicle.

(2) Fire: First and foremost is to save ourselves from fire. Then one can help others in rescue operations. Help others to extinguish fire. Call the fire department for immediate action.

(3) Snake bite: Many a times the biting snake can be non-venomous too. But the victim is psychologically affected too. The tourniquet should be tied in the region above the snake bite. The rope, piece of cloth or even handkerchief can be used for this purpose, so that the venom, if any should not rise and reach vital organs. The wound should be made near the bite-wound so that the blood will ooze out and some venom can automatically flow out. Though these are first-aid measures, the victim should be rushed to a qualified doctor for an injection of antivenin.

Choose the correct alternative and write its alphabet against the sub-question number:

Question 1.
Disasters definitely affect the ………… of the nation.
(a) people
(b) economy
(c) security
(d) employment
Answer:
(b) economy

Question 2.
If local ………… is not strong enough, citizens become confused.
(a) leadership
(b) women
(c) politicians
(d) cattle
Answer:
(a) leadership

Question 3.
…………… problems arise diming the disaster.
(a) Local
(b) Global
(c) Administrative
(d) Private
Answer:
(c) Administrative

Question 4.
Stinking pollution caused due to decomposing corpses of humans and other animal is ………… disaster.
(a) environmental
(b) health
(c) necessary
(d) effective
Answer:
(a) environmental

Question 5.
After the subsidence of any type of disaster, rehabilitation work is started in ………… phase.
(a) later
(b) transitional
(c) terminal
(d) ultimate
Answer:
(b) transitional

Question 6.
…………. phase is highly complicated phase.
(a) Reconstruction
(b) Recycling
(c) Reuse
(d) Redevelopment
Answer:
(a) Reconstruction

Question 7.
There had been a huge ……….. in the village Malin, Tal. Ambegaon in 2014.
(a) earthquake
(b) storm
(c) landslide
(d) change
Answer:
(c) landslide

Question 8.
The atomic energy plant at Chernobyl was used only for generating ………….
(a) electricity
(b) solar power
(c) atomic energy
(d) agriculture
Answer:
(a) electricity

Question 9.
Supply of essential ………….. to the affected people can reduce the effect of the disaster.
(a) food
(b) water
(c) commodities
(d) money
Answer:
(c) commodities

Question 10.
Keeping …………. ready is a practice to check the preparedness of facing the disaster.
(a) First aid
(b) Mock drill
(c) Ambulance
(d) Fire brigade
Answer:
(b) Mock drill

Question 11.
Which of the following is man-made disaster. (March, July ’19)
(a) Earthquake
(b) Flood
(c) Meteor
(d) Leakage of toxic gases
Answer:
(d) Leakage of toxic gases

Question 12.
What should be done if gas cylinder at your house catches fire?
(a) Water should be sprinkled
(b) Sand, soil should be put on it
(c) Cylinder should be covered with wet blanket
(d) one should run away
Answer:
(c) Cylinder should be covered with wet blanket

Which type of disaster is described in the following statements:

Question 1.
On 26th July 2005, entire suburban Mumbai was waterlogged.
Answer:
Cloudbursting and severe downpour

Question 2.
Elephants in the Bandipur forest started running helter and skelter due to smoke.
Answer:
Forest fires

Question 3.
Many innocent people died in the bomb blast that occurred on 11th July 2006 in local trains.
Answer:
Bomb explosion-Terrorism

Question 4.
In Kutch, suddenly many school children were buried under the rubble.
Answer:
Earthquake

Question 5.
Because of lack of crops, people from Vidarbha are migrating to other regions.
Answer:
Dry famine

Question 6.
The huge waves in Chennai engulfed many human lives in December 2004.
Answer:
Tsunami.

Find the correlation:

Question 1.
Earthquake in recent times : Gujarat, Latur : : Devastating floods in 2018 : ………….
Answer:
Earthquake in recent times : Gujarat, Latur : : Devastating floods in 2018 : Kerala/Assam

Question 2.
Toxic gas leakage: Accidental disaster : : war : …………..
Answer:
Toxic gas leakage: Accidental disaster : : war : Intentional

Question 3.
Sun spots : Atmospheric type of disaster : : Salinization : …………..
Answer:
Sun spots : Atmospheric type of disaster : : Salinization : Geological type of disaster

Question 4.
Pre-disaster management : Preparation and warning : : Post-disaster management : ………..
Answer:
Pre-disaster management : Preparation and warning : : Post-disaster management : Resurgence and restoration.

Match the columns:

Question 1.

Column A: Disaster	Column B: Type
(1) Earthquake and volcano	(a) Animal origin
(2) Snowfall and snowstorms	(b) Geological
	(c) Climatic
	(d) Terrorism

Answer:
(1) Earthquake and volcano – Geological.
(2) Snowfall and snowstorms – Climatic.

Question 2.

Column A: Disaster	Column B: Type
(1) Aquatic weeds	(a) Animal origin
(2) Attack by locusts (insects)	(b) Plant origin
	(c) Geological
	(d) Climatic

Answer:
(1) Aquatic weeds – Plant origin
(2) Attack by locusts (insects) – Animal origin.

Question 3.

Column A: Disaster	Column B: Type
(1) Atomic tests	(a) Intentional
(2) Terrorism	(b) Unintentional
	(c) Geological
	(d) Animal origin

Answer:
(1) Atomic tests – Unintentional
(2) Terrorism – Intentional.

Question 4.

Column A: Effect	Column B: Effect
(1) Contamination of water	(a) Economical
(2) Collapsing of transport system	(b) Environmental
	(c) Administrative
	(d) Geological

Answer:
(1) Contamination of water – Environmental
(2) Collapsing of transport system – Administrative.

Question 5.

Column A: Effect	Column B: Problem
(1) Spread of epidemics	(a) Economical
(2) Shortage of funds	(b) Administrative
	(c) Medical
	(d) Physical

Answer:
(1) Spread of epidemics – Medical
(2) Shortage of funds – Economical.

Question 6.

Column A: Effect	Column B: Problem
(1) Rift due to religions	(a) Economical
(2) Citizens getting confused	(b) Social
	(c) Political
	(d) Environmental

Answer:
(1) Rift due to religions – Social
(2) Citizens getting confused – Political.

Identify the type of disaster and describe the effects of the same in brief:

Question 1.
Accident at Chernobyl.
Answer:
Man-made, unintentional. At Chernobyl in Russia there was the atomic energy plant, where disastrous accident took place. The radiations emitted through the reactors caused tremendous radiation pollution. These hazardous effects are even seen today.

Give reasons:

Question 1.
When there are riots, the cities, towns or villages show signs of tense atmosphere.
Answer:

During riots, there is financial loss for all the rioting groups.
The belongings, houses, shops, etc. are destroyed or damaged.
Property is looted. There is no guarantee of safety and security for anyone.
Women and children suffer the most as they are easily victimized. Therefore, when there are riots, the cities, towns or villages show signs of tense atmosphere.

Answer the following questions in detail:

Question 1.
which are the disaters that make Impact for longer duration? Give examples.
Answer:
Those disasters that make the impact for long duration and those disasters, whose after-elfbcts are either severe are long term disasters. Their severity increases with thme. Such disasters are famine, various problems of growth of crop, strikes of workers, rising levels of oceans, desertification, etc.

Question 2.
What types of disaster are the following? Explain their impacts.
(a) Floods (b) War. (Board’s Model Activity Sheet)
Answer:
(a) Flood is geophysical climatic disaster.
(b) War is man-made intentional disaster.

Impact of flood : The low-lying and the coastal areas are seen to be submerged. The entire region is waterlogged.
Impact of war: Tremendous destruction causing loss. Many lives are lost. The costs of all the items rise due to war conditions. Entire nation faces insecurity.

Question 3.
Explain in brief the sensitive issues of general public about disaster.
(OR)
Which are the three aspects of disaster tjiat are important for common citizens?
Answer:
The phase of emergency, transitional phase and reconstruction phase are the three phases of disaster that are important for common citizens.

(1) Phase of emergency: If timely and rapid action is taken during this phase, maximum lives can be saved. Search and rescue operations, medical help, first aid, restoring communication services, removing the people from affected area are done during this phase. The gravity of disaster can be estimated during this phase.

(2) Transitional Phase: The disaster subsides and then the work of transitional phase starts. The main concern is rehabilitation work for the affected and displaced people. This work includes clearing of debris, restoring water supply, repairing roads, etc. to bring normalcy in public life. Help from different voluntary and Government institute is taken to offer the monetary provision and essential commodities to affected victims. Permanent means of livelihood is given to the people to reduce their mental and emotional stress. The victims are truly rehabilitated.

(3) Reconstruction Phase: Reconstruction phase is a highly complicated phase which actually overlaps with transition stage. Help is offered to people to reconstruct their buildings. Other facilities like roads and water supply are restored. Farming practices are restarted. It is a very gradual phase that makes the victims to completely rehabilitate.

Question 4.
What are the objectives of mock drill?
Answer:
Objectives of Mock Drill:

To evaluate the response of the people to the disaster.
To improve the coordination between various departments of disaster control.
To identify one’s own abilities if disaster approaches.
To improve the ability to quick response to disaster and taking rapid action.
To check the competency of the planned actions.
To identify the possible errors and risks while dealing with disasters.

Question 5.
Write down the names of international organizations that work for disaster management.
Answer:
Following international organizations work for disaster management.

United Nations Disaster Relief Organization
United Nations Centre for Human Settlements
Asian Disaster Reduction Centre.
Asian Disaster Preparedness Centre.
World Health Organization.
United Nations Educational, Scientific and Cultural Organization.

Question 6.
The building in which you are residing ( has caught fire on the ground floor. What necessary rescue steps will you take? (July ’19)
Answer:

We shall call out for help.
We shall immediately call fire brigade.
We shall try to extinguish fire with the help of other people.
We will give first aid to people who are injured, fill the medical help arrives.
We will cover our nose and mouth with moist cloth to prevent suffocation.

Write short notes:

Question 1.
Pre-disaster management.
Answer:
The management measures taken before onset of a disaster is called pre-disaster management.
In pre-disaster management, complete preparation and planning to face any type of disaster is done. For this purpose, following steps are taken.

Identifying the areas where the disaster can strike. Such disaster-prone areas are to be thoroughly studied.
Through predictive intensity maps and hazard maps, the information is collected about the intensity of disaster and probable sites of disasters respectively.
Special training for disaster management is given to the concerned people.
The mass awareness is created about disaster management through training programmes, mass media and internet, etc.

Question 2.
Post-disaster management.
Answer:
The management measures taken after the striking of a disaster is called post-disaster management.
Following steps are taken during post-disaster management:

Helping the victims of disasters by giving all possible help needed for their survival.
Local people are trained to take part in the disaster management so that affected people can be saved rapidly.
Establishing the help centres that could provide all the necessary help. Such centres will be different in case of different disasters.
Collection and categorization of the material received from control centre for helping the victims. Distributing the same and reviewing the measures continuously.
Disaster rescue programmes are mainly focused.

Some symbols are given below. Explain those symbols. Which disasters may occur if those symbols are ignored?

Question 1.
Write what the signs indicate:

Answer:

Figure A indicates inflammable substances. They can catch fire if they come in contact with oxygen-rich air.
Figure B indicates corrosive substances which can cause damage to tissues of skin, eyes and other delicate organs etc.
Both the symbols are warning signs for people to keep away or handle carefully such substances.

Question 2.
What does the symbols below indicate? Write in brief. (Board’s Model Activity Sheet)

Answer:
(1) Symbol ‘A’ indicates Irritant. When skin or any delicate part of the body comes in contact with the irritant substance, it can cause harmful reaction. Especially, eyes, nasal mucosa and skin are affected by contact with corrosive substances.
(2) Symbol ‘B’ indicates toxic substance. To taste a toxic substance or even to smell it, can lead to death. The packing of these substances are therefore marked as dangerous. They should be avoided as far as possible.

Complete the paragraph by choosing the appropriate words given in the brackets:

(Capability, Rehabilitation, Commodities, Human, objectives, normalcy, amusements)
The ………. of disaster management comprise of the following aspects …………. life is saved from the disasters. People are helped to move away from the place of disasters. They are given essential ……….. by the government so that the gravity of disaster is reduced. The disaster conditions are brought back to ………… of the affected and displaced victims is done. Moreover, protective measures for future are also planned to develop ………… among the people to face any possible disasters in future.
Answer:
The objectives of disaster management, comprise of the following aspects. Human life is saved from the disasters. People are helped to move away from the place of disasters. They are given essential commodities by the government so that the gravity of disaster is reduced. The disaster conditions are brought back to normalcy. Rehabilitation of the affected and displaced victims is done. Moreover, protective measures for future are also planned to develop capability among the people to face any possible disasters in future.

Paragraph based questions:

1. Read the paragraph and answer the questions given below:
Disasters can be properly classified into three categories, viz. natural disasters, technological disasters and man-made disasters. The forces that cause natural disasters cannot be controlled. Moreover, they are becoming more frequent in the current years due to phenomena of climate change. On and off incidences of cyclones, cloud bursting, floods, etc. am creating havoc in the lives of people. Technological disasters are due to improper and callous behaviour at the different processes carried out in technical establishments. Man-made disasters are conflicts arising due to different religions, regions and-terrorism.

Questions and Answers:

Question 1.
What are three broad areas of disasters?
Answer:
Natural disasters, technological disasters and manmade disasters are three broad areas of disasters.

Question 2.
Which disasters cannot be controlled? Why?
Answer:
Natural disasters cannot be controlled as they are due to natural phenomena beyond the human power to stop them.

Question 3.
Which type of disasters were very common in Western Maharashtra in recent times? Why?
Answer:
Cloud bursting and floods were very common in Western Maharashtra caused due to climate change.

Question 4.
Give any one example of technological disaster that shook the entire India.
Answer:
Bhopal gas tragedy that occurred in 1984 was a worst disaster that shook the entire India.

Question 5.
Which types of disasters can be controlled in order to lead happy, peaceful and secured life? How?
Answer:
We have to control manmade disasters such as wars, riots, terrorism, etc. by having peaceful negotiations, respect for each human being and feeling of brotherhood among all.

Questions based on tables and charts:

Question 1.
Complete the chart: (Text Book Page No. 111)
Different problems occur with disasters. In the concept map different effects are mentioned. Read it and fill the blank places.
Answer:
(Answers are given directly in bold.)

Question 2.
Complete the chart: (Text Book Page No. 117)
Complete the chart as per the objectives of the first aidr:t
Answer:
(Answers are given directly in bold.)

Activity based questions:

Question 1.
Observe the images ‘A’ and ‘B’ and answer the following questions.

(i) Which disasters are shown in the images ?
Answer:
Image A is showing damage due to earthquake. Image B is showing house on fire.

(ii) Which primary precautions will you take in case of disaster shown in ‘A’?
Answer:
In the above disasters, the initial precautions to be taken are as follows :
Earthquake: In case of earthquake, one should immediately come out of house and stand in the open ground. If this is not possible, one has to go below table or any other cover. During collapse of the building, there should not be a head injury. This precaution is basically for prevention of dangerous injuries and saving our life. Switch off the power supply. If in journey, stay inside the vehicle.

(iii) Which type of first-aid is offered to the injured people in disaster ‘B’?
Answer:
First aid given to burn victim:

The person who is injured by fire should be dotised with cold water on his/her body. This will extinguish fire and give some relief caused due to inflammation. Do not break the blisters. Give water to drink.
Cover the burnt part by wet and moist cloth. Wash the wounds with antiseptic solution.
If the person is severely burnt, transfer him/her immediately to hospital.

Question 2.
Correct the following diagram:

Answer:

Projects:

Project 1.
Can you tell? ( Textbook page no. 118)
Whether there had been mock drill by fire fighters under the disaster management scheme in your school? Which techniques did you see during the drill?

Project 2.
Try this: (Textbook page no. 115)
Which factors will you consider while designing the pre-disaster management plan for your school/home? Prepare a survey report with the help of your teacher.

Project 3.
Get information:
(1) Visit the district collector or Taluka Tehasildar office and collect the information about disaster management. (Textbook page no. 115)
(2) Meet the medical officer/doctor from your village and collect information about providing the first aid. (Textbook page no. 118)

Project 4.
Internet is my friend:
(1) Search for the video clips of disasters. Discuss in your class about effects of disasters and remedies over it. (Textbook page no. 110)
(2) Find out more about the activities of international organizations that work for disaster management.
(Textbook page no. 116)
1. United Nations Disaster Relief Organization.
2. United Nations Centre for Human Settlements.
3. Asian Disaster Reduction Centre.
4. Asian Disaster Preparedness Centre.
5. World Health Organization.
6. United Nations Educational, Scientific and Cultural Organization.

10th Std Science Part 2 Questions And Answers: