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Balbharti Maharashtra State Board Class 6 Science Solutions Chapter 8 Our Skeletal System and the Skin Notes, Textbook Exercise Important Questions and Answers.

Std 6 Science Chapter 8 Our Skeletal System and the Skin Question Answer Maharashtra Board

Class 6 Science Chapter 8 Our Skeletal System and the Skin Question Answer Maharashtra Board

1. Fill in the blanks with the proper word. 

Question a.
The place where two or more bones are connected is called a …………… .
Answer:
joint

Question b.
Cells of epidermis contain a pigment called ………… .
Answer:
melanin

Question c.
…………… and ……………. are the two layers of the human skin.
Answer:
epidermis, dermis

Question d.
The human skeletal, system is divided into ………….. parts.
Answer:
two

2. Match the pairs.

Question a.

Column ‘A’	Column ‘B’
1. Ball and socket joint	a. Knee
2. Hinge joint	b. Wrist
3. Gliding joint	c. Shoulder

Answer:

Column ‘A’	Column ‘B’
1. Ball and socket joint	c. Shoulder
2. Hinge joint	a. Knee
3. Gliding joint	b. Wrist

3. Right or wrong? If wrong, write the correct sentence. 

Question a.
Bones are soft.
Answer:
Wrong: Bones are hard.

Question b.
The human skeleton protects the internal organs.
Answer:
Right

4. Put a [✓] mark at the proper places.

Question a.
The system which gives our body. a definite shape to
(a) Excretory system [ ]
(b) Respiratory system [ ]
(c) Skeletal system [ ]
(d) Circulatory system [ ]
Answer:
(c) Skeletal system [✓]

Question b.
The ………… joint is seen in fingers and toes.
(a) Hinge joint [ ]
(b) Ball and socket joint [ ]
(c) Immovable joint [ ]
(d) Gliding joint [ ]
Answer:
(a) Hinge joint [✓]

5. Answer the following questions in your words.

Question a.
What are the functions of your skin?
Answer:
The functions of the skin are :

1. Protects the internal parts of the body like muscles, bones, organ systems etc.
2. Help to preserve the moisture in the body.
3. Synthesizing Vitamin D.
4. Regulates body temperature by releasing sweat.
5. Gives protection from heat and cold.
6. Functions as the sensory organ of touch

Question b.
What should you do to keep the bones strong and healthy?
Answer:
To keep the bones strong and healthy:

1. We should include calcium and phosphrous rich food in our diet.
2. We also include vitamin D rich food in our diet.
3. We get these from milk, milk products, leafy vegetables, meat and exposure to sunlight.
4. We should exercise regularly.

Question c.
What are the functions of human skeletal system?
Answer:
The functions of human skeletal system are:

1. Gives a definite shape to the body.
2. Provides support to the body.
3. Protects the delicate organs inside the body.

Question d.
Which are the various reasons due to which our bones might break?
Answer:
The bones in our body might break due to:

1. Lack of calcium and phosphorous.
2. Due to fracture because of an accident or a fall.
3. Lack of proper nutrition.
4. Due to deficiency of Vitamin D.

Question e.
What are the different types of bones? How many types are there? Give example of each.
Answer:
There are four types of bones in our body:

Types of Bone	Example
1. Flat bones	Sternum in the chest
2. Small bones	Stirrup in each ear
3. Irregular bones	Vertebra posterior (back side) of the body
4. Long bones	Femur or thigh bone

Types of Bone Example

1. Flat bones Sternum in the chest
2. Small bones Stirrup in each ear
3. Irregular bones Vertebra posterior (back side) of the body
4. Long bones Femur or thigh bone

6. What will happen if?

Question a.
There are no joints in our body.
Answer:
If there are no joints in our body, we will be standing like a tree without any movement, we can move only because of joints.

Question b.
There is no melanin pigment in our body.
Answer:
We will not have protection from ultraviolet rays. Our skin will become whitish.

Question c.
Instead of 33 vertebras in our body, we had one single and straight bone.
Answer:
We cannot bend down at our will.

7. Draw diagrams.

Question a.
Types of joints.
Answer:

Question b.
Structure of skin
Answer:

Activity:

Question 1.
Collect pictures of the different parts of the human skeletal system and paste them on chart paper. Write the functions of
each, too.

Question 2.
Collect the pictures, newspaper cuttings, etc. which show the skeletal systems of various animals and observe the differences between them.

Class 6 Science Chapter 8 Our Skeletal System and the Skin Important Questions and Answers

Choose the correct alternative:

Question 1.
The ………………….. protects the brain.
(a) skull
(b) rib cage
(c) spine
(d) none of above
Answer:
(a) skull

Question 2.
X-rays were discovered by …………………..  .
(a) Sir C.V.Raman
(b) Galileo
(c) Sir Isaac Newton
(d) Roentgen
Answer:
(d) Roentgen

Question 3.
The bones of ………………….. are immovable.
(a) hand
(b) leg
(c) spine
(d) skull
Answer:
(d) skull

Question 4.
We can move the bones of ………………….. in a 360° angle.
(a) elbow
(b) knee
(c) shoulder
(d) wrist
Answer:
(c) shoulder

Question 5.
Our body temperature usually remains constant at ………………….. °C.
(a) 32
(b) 35
(c) 37
(d) 40
Answer:
(c) 37

Question 6.
The part of the skin which maintains body temperature is ………………….. .
(a) Epidermis
(b) Dermis
(c) Subcutaneous layer
(d) Network of blood vessels and nerve fibers
Answer:
(c) Subcutaneous layer

Fill in the blanks:

Question 1.
Except for the …………….., none of the bones of the skull can move.
Answer:
lower jaw

Question 2.
The spinal cord originates from the …………… .
Answer:
brain

Question 3.
The longest and the strongest bone in the human body is …………… .
Answer:
femur

Question 4.
…………….. is the smallest bone in our body.
Answer:
stirrup

Question 5.
The vertical, flat bone in the chest is called the ……………… .
Answer:
sternum

Question 6.
The …………… joint moves in a 180° angle.
Answer:
hinge

Match the columns:

Question 1.

Column ‘A’	Column ‘B’
1. Skull	a. 25 bones
2. Rib cage	b. 6 bones
3. Spine	c. 22 bones
4. Both ears	d. 33 bones

Answer:

Column ‘A’	Column ‘B’
1. Skull	c. 22 bones
2. Rib cage	a. 25 bones
3. Spine	d. 33 bones
4. Both ears	b. 6 bones

Question 2.

Column ‘A’	Column ‘B’
1. Lower jaw	a. Movable joint
2. Ears	b. Femur
3. Thigh	c. Movable joint in skull
4. Elbow	d. Smallest bone

Answer:

Column ‘A’	Column ‘B’
1. Lower jaw	c. Movable joint in skull
2. Ears	d. Smallest bone
3. Thigh	b. Femur
4. Elbow	a. Movable joint

Right or Wrong? If wrong, write the correct answers:

Question 1.
The spine is a part of the appendicular skeleton.
Answer:
Wrong: The spine is a part of the axial skeleton.

Question 2.
Ankle joints are gliding joints.
Answer:
Right

Question 3.
All the skull joints are immovable.
Answer:
Wrong: Except lower jaw, all the skull joints are immovable.

Question 4.
The skin maintains normal body temperature.
Answer:
Right

Answer in one word:

Question 1.
The part which protects the heart and lungs.
Answer:
Rib cage

Question 2.
Ali falls down and his elbow is broken.
Answer:
Fracture

Question 3.
The image which spots the broken bone.
Answer:
X-ray

Question 4.
The biotic component of our body.
Answer:
Bone cell

Question 5.
The part which protects the vertebral column.
Answer:
Spine

Question 6.
The part which connects the bone in our body.
Answer:
Ligament

Question 7.
The organ which helps us to sense whether something is hot or cold.
Answer:
Skin

Question 8.
The pigment which gives colour to the skin.
Answer:
Melanin

Can you tell?

Question 1.
What is a fracture? How will you help a friend who has met with an accident and fractured his leg?
Answer:
Fracture is a crack or break in a bone. Fracture may occur due to accident or fall from height or injury. If my friend’s leg is fractured, then. I would –

1. Ask him to prevent any movement of the fractured part.
2. Get immediate medical help.
3. Take the x-ray image of the fractured or swollen part.
4. An x-ray image shows the exact spot where the bone is broken. This will help in providing proper treatment.

Question 2.
What are the properties of bones?
Answer:
The properties of bones are:

1. Bones are hard and not flexible.
2. Bone cells are composed of two main constituents:
   • Bone cells are biotic components.
   • Calcium carbonate, calcium phosphate, minerals and salts are abiotic components.
3. Calcium imparts strength to bones.
4. As we grow the size and length of bones increases upto a certain limit.

Question 3.
What is human skeletal system? How is it divided?
Answer:

1. All the bones together form a framework or a skeleton.
2. All the bones of the body along with cartilage together form the skeletal system.
3. The human skeletal system can be divided into two parts – the axial skeleton and the appendicular skeleton.
4. The axial skeleton consists of the skull, the spine and the rib cage. These are situated symmetrically along the central axis.
5. The appendicular skeleton consists of the bones of arms and legs on either side of the central axis.

Question 4.
What is a joint? What are it’s types?
Answer:
Joints are places where two or more than two bones are connected to each other.

Question 5.
Describe the structure of skin.
Answer:

1. Human skin is made up of two main layers- outermost layer, epidermis and layer below it called dermis.
2. Below dermis there is a network of blood vessels and nerve fibers.
3. Under this layer there is a subcutaneous layer, which maintains body temperature.
4. The epidermis has various layers.
5. There are sweat glands in the skin which secrete sweat.

Question 6.
Write a short note on melanin.
Answer:

1. Melanin is a pigment present in the cells of epidermis.
2. Melanin is synthesized in certain glands in the skin.
3. The percentage of melanin decides the fairness or darkness of the skin.
4. Melanin protects our skin and the inner parts from ultraviolet sunrays.

Use your brain power!

Question 1.
Which colour of the skin will give greater protection from sun’s rays?
Answer:
Darker colour will give greater protection.

Give scientific reasons:

Question 1.
We are able to bend down at our will.
Answer:

1. 33 bones of the spine are placed straight one above the other.
2. They are arranged flexibly.
3. Their flexibility allows us to bend down at our will.

Question 2.
Calcium is an important mineral.
Answer:

1. Calcium imparts strength to our bones.
2. If we are calcium deficient, possibility of bone fracture during a fall or an accident increases.
3. Hence, calcium is an important mineral.

Question 3.
Sweating helps to lower the body temperature.
Answer:

1. In the hot sun, the temperature of the skin rises.
2. The sweat is released.
3. The heat required for the evaporation of sweat is drawn from the body itself.
4. Hence, sweating lowers the body temperature.

Question 4.
Some people have jet black hair, while others have brown or reddish hair.
Answer:

1. It is melanin that determines the colour of our hair.
2. Jet black hair is due to pure melanin.
3. Brown hair is due to sulphur in the melanin.
4. Reddish hair is due to iron in the melanin.

Question 5.
Observe and discuss:
Your grandmother has wrinkles on her skin.
Answer:

1. As we grow older, the proportion of fat beneath the skin reduces.
2. However, previously tout skin does not shrink.
3. This causes wrinkles on the face of older people.

What will happen if:

Question 1.
If skin had no sweat glands.
Answer:
Skin regulates body temperature by releasing sweat. If skin had no sweat glands then we will not be able to maintain our body temperature at a constant 37°C.

Can you recall?

Question 1.
Which organ help us to sense whether something is hot or cold, rough or smooth, etc?
Answer:
The skin functions as the sensory organ of touch.

Question 2.
What happens when we walk or play in the hot sun?
Answer:
When we walk or play in the sun, we get tired, our skin secrete sweat.

Observe the figure and label as directed.

Question 1.

In the above figure label the parts marked a, b, c, d, e and hence show axial and appendicular
skeleton.
Answer:
(a) Skull
(b) Rib cage
(c) Spine
(d) Arm
(e) Leg
Axial skeleton: skull, the spine and rib cage
Appendicular: legs, arms

Question 2.

In the given figure, name the type of bones marked a, b, c, d. State where they are seen in our body.
Answer:
(a) Flat bones – rib cage and gliding joint
(b) small bones – finger
(c) Irregular bones – vertebal column
(d) Long bones – legs, arms

6th Std Science Questions And Answers:

• Natural Resources – Air, Water and Land Class 6 Questions And Answers
• The Living World  Class 6 Questions And Answers
• Diversity in Living Things and their Classification Class 6 Questions And Answers
• Disaster Management Class 6 Questions And Answers
• Substances in the Surroundings – Their States and Properties Class 6 Questions And Answers
• Substances in Daily Use Class 6 Questions And Answers
• Nutrition and Diet Class 6 Questions And Answers
• Our Skeletal System and the Skin Class 6 Questions And Answers
• Motion and Types of Motion
• Force and Types of Force Class 6 Questions And Answers

Balbharti Maharashtra State Board Class 6 Science Solutions Chapter 16 The Universe Notes, Textbook Exercise Important Questions and Answers.

Std 6 Science Chapter 16 The Universe Question Answer Maharashtra Board

Class 6 Science Chapter 16 The Universe Question Answer Maharashtra Board

1. Name these.

Question a.
Birthplace of stars.
Answer:
Nebulae

Question b.
The biggest planet in the Solar System.
Answer:
Jupiter

Question c.
The galaxy which is our neighbour.
Answer:
Andromeda

Question d.
The brightest planet in the solar system.
Answer:
Venus

Question e.
Planet with the largest number of satellites.
Answer:
Jupiter

Question f.
Planet without a single satellite.
Answer:
Venus and Mercury

Question g.
Planet with a rotation different from other planets.
Answer:
Venus

Question h.
A celestial body that carries a tail along.
Answer:
Comet

2. Fill in the blanks.

Question a.
The group of galaxies of which our Milky Way is a part is called ………….. .
Answer:
Local group

Question b.
Comets are made of ………… .
Answer:
ice and dust particles

Question c.
The planet ……………… appears as if it is rolling along its orbit.
Answer:
Uranus

Question d.
…………….. is a stormy planet.
Answer:
Jupiter

Question e.
The pole star is the best example of a ………………. type of star.
Answer:
variable

3. Say if the statements given below are right or wrong. Rewrite the statements after correcting them.

Question a.
Venus is the planet closest to the sun.
Answer:
Wrong: Mercury is the planet closest to the sun.

Question b.
Mercury is called a stormy planet.
Answer:
Wrong: Jupiter is called a stormy planet.

Question c.
Jupiter is the biggest planet.
Answer:
Right

4. Answer the following.

Question a.
What is a special characteristic of the planet Mars?
Answer:
The highest and the longest mountain in the solar system ‘Olympus Mons’ is located on Mars.

Question b.
What are the type of galaxies?
Answer:
The different types of galaxies identified according to their shapes are spiral, elliptical, barred spiral, irregular.

Question c.
Which celestial bodies does a galaxy include?
Answer:
Galaxy includes stars, their planetary system, cluster of stars, nebulae, clouds of gases, clouds of dust, dead stars, newly bom stars etc.

Question d.
Name the different types of stars.
Answer:
The different types of stars are

1. Sun-like stars e.g. stars like Sirius, Alpha Centauri
2. Red Giants Stars
3. Super Nova
4. Binary or Twin Stars
5. Variable Stars e.g. Polaris (pole star)

Question e.
What are the types of comets and on what basis are they classified?
Answer:

1.  Comets are of two types: Long-period comets and short-period comets.
2. Classification of comets is based on the time (period) taken by the comets to complete one revolution around the sun.

Question f.
What is the difference between meteors and meteorites?
Answer:

1. Meteors are rocky pieces originating from the asteroid belt. Smaller rocky pieces get completely burnt due to friction with air after they enter the earth’s atmosphere.
2. Meteors which do not bum completely and fall to the surface of the earth are called meteorites.

Question g.
What are the characteristics of the planet Neptune?
Answer:
Neptune is the eighth planet in the solar system. A season on Neptune lasts for about 41 years. On this planet winds blow with extremely high speed.

5. Match the following.

Question a.

Group ‘A’	Group ‘B’
1. Galaxy	(a) From east to west
2. Comet	(b) 33 satellites
3. Sun-like star	(c) Spiral
4. Saturn	(d) Sirius
5. Venus	(e) Halley

Answer:

Group ‘A’	Group ‘B’
1. Galaxy	(c) Spiral
2. Comet	(e) Halley
3. Sun-like star	(d) Sirius
4. Saturn	(b) 33 satellites
5. Venus	(a) From east to west

Activity:

Question 1.
Using the material you can find in your house, prepare a model of the solar system.

Question 2.
Collect information about different aspects of each planet such as its distance from the sun, its diameter, its volume, etc. and present it in a science exhibition.

Class 6 Science Chapter 16 The Universe Important Questions and Answers

Fill in the blanks.

Question 1.
The Milky Way is known as ………….. .
Answer:
Mandakini

Question 2.
The ………….. is a galaxy in which our solar system is located.
Answer:
Milky Way

Question 3.
The galaxy that is closest to our Milky Way is ………….. .
Answer:
Andromeda

Question 4.
The universe includes innumerable galaxies, the space between them and also ………….. .
Answer:
energy

Question 5.
The Milky Way is a part of the ………….. of galaxies.
Answer:
Local group

Question 6.
Generally, the surface temperature of stars ranges from 3500° C to ………….. .
Answer:
50000°C

Question 7.
The colour of stars changes according to their ………….. .
Answer:
temperature

Question 8.
Red giants stars are ………….. in colour.
Answer:
red

Question 9.
Super Nova stars are ………….. and ………….. than the red giant stars.
Answer:
brighter, larger

Question 10.
More than ………….. of the stars in the sky are ………….. stars.
Answer:
half, binary

Question 11.
The ………….. and ………….. of variable stars is not stable.
Answer:
luminance, shape

Question 12.
When a star contracts, its surface temperature ………….. and the star emits ………….. energy and appears ………….. .
Answer:
increases, greater, brighter

Question 13.
The sun which is at the centre of the solar system is a ………….. coloured star.
Answer:
yellow

Question 14.
The diameter of the sun is approximately ………….. km.
Answer:
13, 92, 000

Question 15.
………….. is the fastest moving planet.
Answer:
Mercury

Question 16.
………….. is the brightest planet in the solar system.
Answer:
Venus

Question 17.
………….. is the hottest planet.
Answer:
Venus

Question 18.
As the earth is a ………….. there is a magnetic field around the earth.
Answer:
magnet

Question 19.
Mars is also called the ………….. .
Answer:
Red planet

Question 20.
As the soil on Mars contains ………….. its colour is reddish.
Answer:
iron

Question 21.
………….. planets of the size of the earth can get accommodated on Jupiter.
Answer:
1397

Question 22.
Jupiter is called as ………….. .
Answer:
The stormy planet

Question 23.
Saturn mass is ………….. times that of the earth.
Answer:
95

Question 24.
………….. cannot be seen without a telescope.
Answer:
Uranus

Question 25.
Winds blow with extremely high speed on ………….. .
Answer:
Neptune

Question 26.
………….. is the satellite of the earth.
Answer:
The moon

Question 27.
The moon’s period of ………….. and ………….. are both of 27.3 days.
Answer:
rotation, revolution

Question 28.
………….. is classified as a dwarf planet.
Answer:
Pluto

Question 29.
Pluto takes ………….. years to complete its revolution around the sun.
Answer:
248

Question 30.
………….. are formed out of ice and dust particles.
Answer:
Comets

Question 31.
………….. lake in Maharashtra has been formed by the impact of such a meteorite.
Answer:
Lonar

Can you tell?

Question 1.
Which celestial bodies form the solar system?
Answer:
Sun, the eight planets – Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, Neptune, their satellites, Dwarf planets, asteroids, meteors and comets all together form our solar system.

Question 2.
What is the difference between stars and planets?
Answer:

Stars	Planets
1. Stars are the celestial bodies which can emit heat and light continuously.	1. The celestial bodies which revolve around the sun in certain orbit are called planets.
2. Stars twinkle in the sky.	2. Planets do not twinkle in the sky.
3. They have their own light.	3. They do not have their own light.
4. They are fixed at a point.	4. They revolve around the sun.
5. They are very big in size.	5. Planets are small as compared to

Question 3.
How many planets are there in our solar system?
Answer:
There are 8 planets in our solar system.

Question 4.
What is to be found between Mars and Jupiter?
Answer:
A belt of celestial bodies called as asteriods is found between the planets Mars and Jupiter.

Question 5.
Have you ever seen in the evening or in the pre-dawn hours a large celestial body with a long tail? What is it called?
Answer:
Yes, it is a comet – a large celestial body with a long tail. I have not seen it, but heard that in 1986 there was a Halley’s comet seen in the Indian sky.

Use your brain power!

Question 1.
Why do we see only one side of the moon?
Answer:
As the moon revolves around the earth it also rotates around itself. The moon takes 27.3 days to complete one revolution around the earth. It takes the moon the same time to complete one rotation around itself. Therefore, only one side of moon is visible.

Question 2.
Which planet has a day longer than its year?
Answer:
A planet’s day is how long it takes to complete one rotation on its own axis. Venus takes 243 earth days to complete one rotation because of its slow rotation around its axis. A year is the time taken by the planet to complete one revolution around the sun. Venus completes one revolution around the sun in 225 days. This makes a day longer than a year on Venus.

Answer in one sentence.

Question 1.
What is the Milky Way?
Answer:
Milky way is the galaxy in which our solar system is located.

Question 2.
What is a galaxy?
Answer:
A group of innumerable stars and their planetary systems are together known as galaxy.

Question 3.
What does the Universe include?
Answer:
The universe includes innumerable galaxies, the space between them and also energy.

Question 4.
What different colours do the stars radiate?
Answer:
The stars radiate different colours such as blue, white, yellow and red.

Question 5.
Where are stars bom?
Answer:
The birth place of stars are the huge nebulae, made of dust particles and gases.

Question 6.
What is the surface temperature of the sun?
Answer:
The surface temperature of the Sim is around 6,000°C.

Question 7.
What is the size of the sun?
Answer:
The size of the sun is so huge that around 13 lakh planets of the size of the earth can be easily placed within it.

Question 8.
How does the sun balance the other celestial bodies?
Answer:
Due to the gravitational force of the sun, the celestial bodies in the solar system revolve around it.

Question 9.
How does the sun move in the Milky Way?
Answer:
The sun rotates around its axis and while doing so, it revolves around the centre of the Milky Way taking the solar system along with it.

Question 10.
Which planet doesn’t have atmosphere?
Answer:
Mercury doesn’t have atmosphere.

Question 11.
How much time does the earth take to complete one rotation and one revolution?
Answer:
The earth completes one rotation in 24 hrs and one revolution in 365 days i.e. 1 year.

Question 12.
Which planets have rings around them?
Answer:
Jupiter, Saturn, Uranus, Neptune have rings around them.

Question 13.
Which planet do not have rings around them?
Answer:
Mercury, Venus, Earth and Mars do not have rings around them.

Question 14.
State two properties of planet Mercury.
Answer:
Mercury is the closet planet to the Sim. Mercury is the fastest moving planet.

Question 15.
When is the Mercury visible to us?
Answer:
Mercury is visible in the morning and in the evening if it is away from the sun.

Question 16.
What is seen on the surface of the mercury?
Answer:
A number of depressions which are actually caused by meteoric falls are seen on the surface of mercury.

Question 17.
When is Venus seen in the sky?
Answer:
Venus is seen in the sky in the east before the sunrise and in the west after the sunset. It rotates around itself from east to west.

Question 18.
How does earth protect us from harmful rays of Sun?
Answer:
As the earth is a magnet there is a magnetic field around the earth. It diverts the harmful rays from the sun towards the polar regions of the earth.

Question 19.
What is Olympus Mons?
Answer:
Olympus Mons is the highest and longest mountain in the solar system located on Mars.

Question 20.
Which is the largest planet of the solar system?
Answer:
The Jupiter is the largest planet of the solar system.

Question 21.
Why is Saturn considered a peculiar planet?
Answer:
Saturn considered a peculiar planet because of the rings around it.

Question 22.
How is the axis of Uranus?
Answer:
Uranus axis is so greatly inclined that it appears as if it is rolling along on its axis.

Question 23.
How are seasons on Neptune?
Answer:
The seasons on Neptune last for about 41 years.

Question 24.
What is a satellite?
Answer:
The celestial bodies that revolve around a planet , without independently revolving around the sun are called Satellite.

Question 25.
What is an Asteroid?
Answer:
A great number of small sized bodies could not turn into planets when the solar system was formed, but continued to revolve around the sun. This bodies are known as asteroids.

Question 26.
What is a Dwarf Planet?
Answer:
A small sized celestial body that revolves independently around the sun is called the dwarf planet.

Question 27.
What is a comet?
Answer:
A comet is a celestial body that revolves around sun. Comets are formed out of ice and dust particles.

Question 28.
What are meteors?
Answer:
Meteors are rocky pieces originating from the asteroids belt.

Question 29.
What are meteorites?
Answer:
Meteors which do not bum completely and fall to the surface of the earth are called meteorites.

Give reasons for the following.

Question 1.
Comets came to be called ‘dirty snowballs’.
Answer:
Comets consist of an icy cluster of various constituents like dust particles. Hence it is called dirty snowballs.

Question 2.
Comets are visible when they are close.
Answer:
Comets are formed out of ice and dust particles. They appear like points when they are far away from the sun, but when they are close to the sun they become easily visible to us because of the shorter distance and the heat of the sun.

Question 3.
Comets appear to have a long feathery tail.
Answer:
Comets are made up of frozen matter and dust particles. When they are close to the sun this frozen matter gets converted into gas due to the solar heat. These gases get thrown in a direction away from the sun. As a result comets appear to have a long feathery tail.

Question 4.
Pluto is called as a dwarf planet.
Answer:
Pluto is a small sized celestial body that revolves independently around the sun.

Question 5.
Moon is a satellite of the earth.
Answer:
Moon revolves around the earth without independently revolving around the sun. Hence moon is a satellite of the earth.

Question 6.
Mars is called the Red Planet.
Answer:
As the soil on the Mars contains iron its colour is reddish. Hence Mars is also called the RedPlanet.

Question 7.
Jupiter is called the Stormy Planet.
Answer:
Jupiter revolves around itself with a great speed. Hence Jupiter is called the Stormy planet.

Question 8.
Uranus appears rolling along on its orbit.
Answer:
Uranus axis is so greatly inclined that it , appears as if it is rolling along on its orbit.

Question 9.
Saturn is considered to be a peculiar planet.
Answer:

1. Saturn is considered as peculiar planet because of its rings around it.
2. Though its mass is 95 times that of the earth, its density is very low.
3. If it were dropped into a large sea enough to hold it, it would float in it.

6th Std Science Questions And Answers:

• Work and Energy Class 6 Questions And Answers
• Simple Machines Class 6 Questions And Answers
• Sound Class 6 Questions And Answers
• Light and the Formation of Shadows Class 6 Questions And Answers
• Fun with Magnets Class 6 Questions And Answers
• The Universe Class 6 Questions And Answers

Balbharti Maharashtra State Board Class 7 Science Solutions Chapter 10 Disaster Management Notes, Textbook Exercise Important Questions and Answers.

Std 7 Science Chapter 10 Disaster Management Question Answer Maharashtra Board

Class 7 Science Chapter 10 Disaster Management Question Answer Maharashtra Board

1. Find the odd man out:

Question a.
Famine, earthquake, cloudburst, railway accident.
Answer:
Railway accident.

Question b.
Drought, heavy rains/storm, tsunami.
Answer:
Drought.

Question c.
Lava, hot mud, ash, locusts.
Answer:
Locusts.

Question d.
Washing away of crops, attack of pests on crops, volcano, singeing of crops.
Answer:
Volcano.

2. What are the remedial measures for the following calamities?

Question a.
Famine:
Answer:
Following are the remedial measures for famine:

1. Supply food and water to the people those who are dying due to hunger.
2. Give medicines to the people those who are suffering from malnutrition.
3. Government should start helping centres for the people those who are suffering from famine.
4. Give them temporary shelter in some other places where water and food are available.
5. Shift the animals to safer places.
6. Do proper planning so that region doesn’t get famine again and again.
7. Reuse water
8. grow more trees.

Question b.
Lightning strike:
Answer:
Following are the remedial measures for lightning strike:

1. Give immediate treatment to the lightning affected persons so their life can be saved.
2. Keep the people away from the open ground and swimming pool.
3. Provide them proper guidelines to cure for the lightning strike.

Question c.
Storm:
Answer:

1. Supply food, water and medicines to the people
2. Shift them to safe places.
3. Maintain peace, and advice the people not to panic.
4. Give time to time report on T.V. and radio.

Question d.
Cloudburst:
Answer:
Following are the remedial measures for cloudburst:

1. Shift people to safe places with the help of airplane, helicopter and army.
2. Supply them food, clothes, water and medicines.
3. Give time to time weather report.
4. Open more helpline centres.
5. Government should immediately send the help in terms of money and army to the people.

3. True or false? Give reasons for your answer.

Question a.
Information about a forthcoming storm is to be kept secret.
Answer:
False. Information about a forthcoming storm is not to be kept secret because, with this information we can take immediate steps for disaster management. Large scale damage of property and loss of life can be avoided.

Question b.
You should not swim when there is lightning in the sky.
Answer:
True. Lightning carries some electric charges which causes electric current in it. Water catches this current so if any person is swimming pool during lightning in the sky, then there are more chances that lightning may strike in water and the person may die due to it.

Question c.
It is possible to prevent the eruption of a volcano.
Answer:
False. It is not possible to prevent the eruption of a volcano because it is a natural event. However, by means of science and technology, it is possible to predict an eruption in advance and to take immediate steps for disaster management.

Question d.
Heavy rains result in famine.
Answer:
True. Heavy rains result in flood so crops get washed away or damaged in the flood and results in famine.

Question e.
A loud crashing sound follows a lightning.
Answer:
True, Friction and brushing happens between two clouds making them charged and lightning is produced between two clouds or one cloud and earth. The temperature increases and air pressure also increases to high amount and produces a loud sound of thunder.

4. Write answers to the following questions in our own words.

Question a.
What is a tsunami? What gives rise to a tsunami?
Answer:

1. Waves generated by an earthquake or volcano occurring on the ocean floor is called ‘tsunami’. ‘Tsunami’ is a Japanese word which means ‘harbour wave’.
2. As on land, earthquakes and volcanic eruptions occur, at the bottom of the sea, too.
3. If an earthquake occurs at the bottom of ocean, the energy released pushes the water upwards. As a result of this particular type of waves are formed.
4. These waves are not very high near the source, but they start spreading very fast to long distances.
5. The velocity of these waves is 800 to 900 km/hr. When they reach a coastal area, their velocity is reduced, but their height is found to have increased tremendously even to about 30 m. These are tsunami waves.

Question b.
What is cloudburst?
Answer:

1. Sometimes the water coming down from rain clouds does not reach the land in the form of rain. Instead, due to very high temperature near the land, it vaporizes and goes back into the same clouds.
2. As a result the amount of vapour in those clouds becomes very high.
3. Due to rapid condensation, it rains suddenly over a specific and small region at a rate of 100 mm per hour or more. This is known as a cloudburst.

Question c.
Explain the effects of a volcano.
Answer:
Following are the effects of a volcano:

1. The chemical substances such as lava, vapour, hot mud, sulphur etc. get collected on the surface of the earth and thereby mountains and hills are created
2. The atmosphere gets polluted due to the ash and gases ejected by the volcano.
3. Often, it rains as a result of a volcanic eruption.
4. The temperature rises due to hot gases.
5. Forests and settlement get buried under the hot mud.

Question d.
What are the measures to prevent loss of life due to lightning?
Answer:
Following are the measures to prevent loss of life due to lightning:

1. Do not stand on open ground, below a tree, on high location, near an electric pole, near a telephone pole or a tower etc.
2. Do not lean on wire fences around a farm, a compound, a garden or a house.
3. If you are on two-wheeler, a bicycle, a tractor or a boat, get off immediately and go to safe place.
4. Do not gather all together in one place.
5. Take care to keep a distance of 15 feet between any two persons.
6. Do not use plugged in electrical appliances. Do not use a mobile or telephone.
7. Stand on dry wood, a plastic sheet, sack or jute cloth or dry leaves.
8. Keeping your feet together support yourself on the soles of your feet placing your hands on your knees and crouch low.
9. Swimmers and fishermen should immediately come out of the water.
10. A pucca house is the safest place. Find out if there is a lightning conductor on any tall building near your house. If necessary get a lightning conductor fitted on your house.

5. What measures have been taken to deal with calamities such as floods and landslides under the disaster management programme in Maharashtra?

Question a.
What measures have been taken to deal with calamities such as floods and landslides under the disaster management programme in Maharashtra?
Answer:
In Maharashtra, all districts have their own disaster management plan to deal with calamities such as floods and landslides.

1. The plan deals extensively with the emergency, and evacuation measures to be taken up in cases of flood and landslide.
2. The district-level disaster management plan has detailed information about geographical details, population, flood-prone areas, villages and other macro details.
3. Nearly 14 such key departments are engaged in disaster mitigation measures and each one has been assigned a specific task to do at times of natural disasters.
4. The administration is now training master trainers at the district level who in turn will train key persons at village and taluka levels to deal with a natural disaster.
5. The administration through radio jingles, public advertisements and other measures is informing people about how to react at times of flood and landslide.
6. Currently, the Indian Meteorological Department (IMD) gives weather forecast on daily basis and for the next 5 days with advice to farmers on when to start crop sowing and harvesting etc.

6. With reference to disaster management what are the things in your house that you will check?

Question a.
With reference to disaster management what are the things in your house that you will check?
Answer:
With reference to disaster management, we should keep the following things at home and check regularly.

1. Keep proper first aid kit at a handy place.
2. Keep all the electric connections in proper condition.
3. Keep the gas line or tube connection proper.
4. Keep self-powered flashlights and self-powered radios.
5. Keep non-perishable food which will last for a week.
6. Keep a fire extinguisher handy and in proper condition.
7. Keep updated telephone diary which should have emergency phone numbers.

Project:

Question 1.
With the help of the Internet, collect information about the places where a calamity has occurred.

Question 2.
Collect information from the Internet about how cyclonic storms are named.

Class 7 Science Chapter 10 Disaster Management Important Questions and Answers

Fill in the blanks:

Question 1.
………… and ………… disasters are related to each other.
Answer:
Natural manmade.

Question 2.
………… implemented a canal scheme for drinking water in Aurangabad.
Answer:
Malik Ambar.

Question 3.
………… has turned out to be the most famine-affected contents of the world.
Answer:
Asia

Question 4.
The government of India established the ………… in 1976.
Answer:
National Flood Commission

Question 5.
The ………… that occurred in Mumbai on 26th August 2005 was extraordinary and unforgettable.
Answer:
cloudburst.

Question 6.
A cloudburst occurred at ………… on 6th August, 2010.
Answer:
Ladakh (Leh)

Question 7.
About ………… lightning flashes occur per second in the atmosphere.
Answer:
40.

Question 8.
The temperature generated by ………… is higher than that of the sun.
Answer:
lightning

Question 9.
When some substances comes out of the earth’s crust in an eruption and start flowing is called a ………… .
Answer:
volcano

Question 10.
Some islands are created due to the eruption, of ………… in the sea.
Answer:
volcano

Question 11.
………… is a Japanese word which means ‘harbour wave’.
Answer:
Tsunami.

Question 12.
About ………… nations from all over the world are members of the UNDP.
Answer:
177.

Question 13.
………… established a standing international organization UNDP in 1965.
Answer:
United Nations.

Question 14.
………… is celebrated as International Day for Disaster Reduction.
Answer:
13th October

Question 15.
The condition that arises due to long term and severe scarcity of food grains and water is called………. .
Answer:
famine

Can you tell?

Question 1.
Is it possible to prevent the loss of life caused by lightning?
Answer:
Yes, it is possible to prevent the loss of life caused by lightning, by taking precautions.

Question 2.
What should be done to prevent the bunds on a farm from getting washed away in the rainy season?
Answer:

1. Grow more trees near the bunds.
2. Grow grass strips.
3. Make stone lines near the bunds.
4. Use contour ploughing and tillage network method to prevent the bunds on a farm from getting washed away in the rainy season.

Question 3.
Why do we experience water scarcity?
Answer:
Lessor no rain leads to water scarcity.

Question 4.
What causes rain?
Answer:

1. Due to heat of the sun, water from the sea, lake and river gets evaporated and this water vapour is light in weight so it goes higher and higher and forms the cloud.
2. At a certain level the amount of vapour in those clouds becomes very heavy and it burst and rain occurs.

Question 5.
Have you seen a flash of lightning in the sky? When?
Answer:
Students will answer this question based on their experience.

Question 6.
What causes lightning?
Answer:

1. Where air and clouds rub against each other in the sky, the upper part of some clouds on the upper side becomes positively charged and the lower sides become negatively charged.
2. When this negative charge on the bottom of the cloud becomes much larger than the charge on the ground it starts flowing towards the ground in stages.
3. This happens very fast, in much less than a second and heat, light and sound energy are produced along with the electric current.

Use your brainpower!

Answer the following questions:

Question 1.
We should not wait at the foothill while it is raining heavily.
Answer:
During heavy rain there are chances of landslide and flood, so we should not wait at the foothill while it is raining heavily.

7th Std Science Questions And Answers:

• The Living World: Adaptations and Classification Class 7 Questions And Answers
• Plants: Structure and Function Class 7 Questions And Answers
• Properties of Natural Resources Class 7 Questions And Answers
• Nutrition in Living Organisms Class 7 Questions And Answers
• Food Safety Class 7 Questions And Answers
• Measurement of Physical Quantities Class 7 Questions And Answers
• Motion, Force and Work Class 7 Questions And Answers
• Static Electricity Class 7 Questions And Answers
• Heat Class 7 Questions And Answers
• Disaster Management Class 7 Questions And Answers

Balbharti Maharashtra State Board Class 7 Science Solutions Chapter 18 Sound: Production of Sound Notes, Textbook Exercise Important Questions and Answers.

Std 7 Science Chapter 18 Sound: Production of Sound Question Answer Maharashtra Board

Class 7 Science Chapter 18 Sound: Production of Sound Question Answer Maharashtra Board

1. Fill in the blanks:

Question a.
Sound is generated by the rhythmic ……………. of any object.
Answer:
vibrations

Question b.
The frequency of sound is measured in …………….. .
Answer:
Hertz (Hz)

Question c.
If …………….. of sound is decreased its loudness also decreases.
Answer:
intensity

Question d.
A medium is necessary for …………… of sound.
Answer:
generation

2. Match the pairs.

Question a.

Column ‘A’	Column ‘B’
1. Flute	a. Frequency less than 20 Hz
2. Frequency	b. Frequency more than 20,000 Hz
3. Sound level	c. Vibrations in the air
4. Ultrasonic sound	d. Measured in Hz
5. Infrasonic sound	e. Decibel

Answer:

Column ‘A’	Column ‘B’
1. Flute	c. Vibrations in the air
2. Frequency	d. Measured in Hz
3. Sound level	e. Decibel
4. Ultrasonic sound	b. Frequency more than 20,000 Hz
5. Infrasonic sound	a. Frequency less than 20 Hz

3. Give scientific reasons.

Question a.
In earlier times, people used to listen for the arrival of a distant train by putting their ear to the rails.
Answer:

1. It was a technique that worked better in those days when train speed were slower than they are today and when there were more rail joints.
2. When people would put their ear to the rail they could hear vibration caused by the wheels moving over the joints. ,
3. Metal being a solid is an efficient medium for the sound to travel and so the sound can propagate further in the rail than would in air as speed of sound is faster in solids than in air.

Question b.
The sounds generated by a tabla and sitar are different.
Answer:

1. In tabla where leather is fitted, sound gets generated when the leather surface is thumped by fingers or palm.
2. The waves thus created travel in two dimensions. Sitar is having strings attached to pumkin box called sound box.
3. Sounds generated by tabla and a sitar are different because they have different pitch and frequencies.

Question c.
If you were both on the moon your friend will not be able to hear you call.
Answer: Yes, your friend will not be able to hear your call because sound needs a medium for transmission since it is a mechanical wave it cannot travel through vaccum.

1. As there is no air on the moon and sound is actually vibration in air.
2. So astronauts communicate to each other by signals or microphones in space even when they are closer.

Question d.
We can hear the movement of a mosquito wings but we cannot hear the movement of our hands.
Answer:

1. Humans cannot hear frequency less than 20 Hz. In the movement of hands oscillations does take place but is less than frequency that humans can hear.
2. Mosquitos wings flap in air.
3. When they fly in air it produces buzzing sound in our ears.
4. The movement of mosquito wings produces sound greater than 20 Hz.
5. Sound is the reception of such waves and their perception by the brain.

4. Write answers to the following questions.

Question a.
How is sound produced?
Answer:

1. Sound is generated due to the vibration of an object, e.g. bell, string or diaphragm of a musical instrument.
2. Vibrations are imparted to the molecules in the air. These vibrations reach our ears through the air and sound is heard.
3. Vibrations of an object is necessary for generation of sound.
4. These vibrations in air are called travelling longitudinal waves which we can hear.

Question b.
What does the intensity of sound depend upon?
Answer:

1. The intensity of sound is proportional to the square of the amplitude of vibration, e.g. If the amplitude is doubled the intensity of sound becomes four times.
2. Therefore the loudness or softness of sound is dependent on the intensity of sound and sound level.

Question c.
Explain how the frequency of oscillation is related to the length of a pendulum and the amplitude of its oscillation.
Answer:

1. Given an oscillatory motion to the pendulum, the maximum distance between the original position A of the pendulum and extreme position B or C is called the amplitude of oscillation. AB, AC is the amplitude of oscillation.
2. The number of oscillations completed by an oscillator in one second is called the frequency of oscillation.

Relation between frequency and length of a pendulum: If the length of the pendulum increases the period of oscillations also increases.
We know time period of oscillations = \(\frac{1}{\text { Frequency }}\)
If time period increases, frequency decreases, therefore, if the length of the pendulum increases frequency will decrease.
Relation between frequency and amplitude: Frequency of oscillation is independent of its amplitude of oscillation.

Question d.
Explain the two ways by which the pitch of the sound generated by a stretched string can be changed?
Answer:
1. A string vibrates with a particular fundamental frequency. It is however possible to produce pitches with different frequencies from the same string.

2. The two properties of the string that affect its frequency are length and diameter.

3. When the length of a string is changed, it will vibrate with a different frequency. Shorter strings have higher frequency and therefore higher pitch.

4. When a musician presses her finger on a string, she shortens its length. The more fingers she adds to the string, the shorter she makes it, higher will be the pitch.
Diameter: Thick strings with large diameter vibrate slower and have lower frequency than the thin ones.

Project:

Question a.
The bat, a mammal, flies during the night manoeuvering with the help of the ultrasonic sounds it produces. Find out more about this.

Class 7 Science Chapter 18 Sound: Production of Sound Important Questions and Answers

Fill in the blanks:

Question 1.
Bats detect the obstacles in their path by receiving the reflected ………….. .
Answer:
ultrasonic waves

Question 2.
An object that moves back and forth is called ……………. .
Answer:
an oscillator

Question 3.
If the length of a pendulum is increased the time period of oscillation ………………. .
Answer:
increases

Question 4.
The …………… of a wave is the maximum distance moved by the object on either side of the mean position.
Answer:
amplitude

Question 5.
Sound waves do not travel through ……………… .
Answer:
vaccum

Question 6.
The frequency above which sound is not audible to the human ear is …………….. .
Answer:
50,000 Hz

Question 7.
Number of vibrations in a second is called …………….. .
Answer:
frequency

Question 8.
Higher the frequency greater will be the ………….. .
Answer:
Pitch

Question 9.
The loudness of sound depends on ………….. .
Answer:
amplitude

Question 10.
Loudness of sound is measured in units of ………………. .
Answer:
decibel dB

Question 11.
100 hertz is equal to hundred oscillations in ………………. .
Answer:
one second

Name the following:

Question 1.
The sound frequencies above 20,000 Hz.
Answer:
ultrasonic

Question 2.
The medium through which sound is most clearly propagated.
Answer:
solids

Question 3.
The range of frequency in which humans can hear sound.
Answer:
20 – 20,000 Hz

Question 4.
The sound level physically painful to humans.
Answer:
above 100 dB

Question 5.
The technique used by bats to find their way.
Answer:
echolocation

Question 6.
The unit of frequency of sound.
Answer:
Hertz

Question 7.
The unit of sound level or intensity.
Answer:
Decibel

Question 8.
The scientist in whose honour was the unit decibel named for intensity of sound.
Answer:
Alexander graham Bell

Question 9.
Bats and dolphins can hear these sound frequencies.
Answer:
Ultra sonic sound

Question 10.
The sound frequencies used in RADAR systems.
Answer:
Ultra sonic sound

Answer in one or two sentences:

Question 1.
How is sound produced?
Answer:
Sound is produced by vibration of an object.

Question 2.
What produces sound in human beings ?
Answer:
The vibration of the vocal chords in our larynx or voice box produces sound.

Question 3.
What is oscillatory motion?
Answer:
To and fro motion of an object (oscillator) on either side of a central position is called oscillatory motion.

Question 4.
What is periodic motion?
Answer:
The motion of an object repeated again and again at fixed intervals of time is called periodic motion.

Question 5.
What is frequency of oscillation?
Answer:
The number of oscillations completed by an oscillator in one second is called the frequency of oscillation.

Question 6.
How is intensity of sound and amplitude of vibration related?
Answer:
The intensity of sound is proportional to the square of the amplitude of vibration. For example, if the amplitude is doubled the intensity becomes four times as much.

Question 7.
What happens if the frequency of sound is greater than 1000 Hz or 100 dB?
Answer:
If frequency of sound is increased more than 100dB, the hearing can be temporarily affected which can result in temporary deafness.

Question 8.
What is infrasonic sound?
Answer:
A sound with a frequency less than 20Hz is called infrasonic sound.

Question 9.
What is application of ultrasonic sound?
Answer:
Ultrasonic sound is used in ships as a system known as ‘SONAR’ to detect the obstacle beneath the ocean as well as the depth of an ocean.

Question 10.
What is the difference between pitch and frequency?
Answer:
Pitch is directly proportional to the frequency of a sound whereas frequency is the repeating vibrations per unit time.

Question 11.
What happens when the rubber band is stretched with a greater force and released?
Answer:
When a rubber is stretched with a greater force and released, the amplitude increases which in turn result in a louder sound being generated.

Question 12.
What happens to frequency if the amplitude is changed?
Answer:
The frequency remains the same even if the amplitude is increased or decreased.

Define:

1. Echo: It is a repetition of sound due to the reflection of original sound by a large and hard obstacle.
2. Frequency: It is defined as the number of vibrations per unit time.
3. Hertz (Hz): One hertz is one vibration per second.
4. Ultrasonic vibration: Sounds of frequency higher than 20,000 Hz are called the ultrasonic.
5. Time period: The time taken by an object to complete one oscillation is called time period.
6. Amplitude: The distance between the mean or central position to the extreme position of an oscillator on either side is called amplitude.

Say True or False with explanation:

Question 1.
Sound cannot travel in vacuum.
Answer:
True. Sound needs a medium to travel through. Since vacuum does not provide any medium, sound cannot travel through it.

Question 2.
If the amplitude of vibration is large, sound is feeble.
Answer:
False. When the amplitude of vibration of a sound is large, the sound is very loud. The sound is feeble, when the amplitude is small. Loudness of a sound is proportional to the square of the amplitude of its vibration.

Question 3.
For human ears, the audible range is 2 Hz to 20,000 Hz.
Answer:
True. Human being can hear sounds only within the range of 20-20,000 Hz. We cannot hear the sound having frequency out of this range.

Question 4.
The lower the frequency of vibrations the higher is the pitch.
Answer:
False. Pitch of sound increases when the frequency of vibration increases. The pitch of a sound is directly proportional to its frequency.

Question 5.
Unwanted or unpleasant sound is termed as music.
Answer:
False. Unwanted, or unpleasant sounds are termed noise. Sounds which are melodious, and pleasing to ears are called music.

Question 6.
Noise pollution may cause partial hearing impairment.
Answer:
True. Unwanted, unpleasant sounds are called noise. If one is subjected to noise continuously for a long time, one may suffer from partial hearing impairment.

Question 7.
Time taken by an object to complete one oscillation is called time period.
Answer:
True. Time taken by an object to complete one oscillation is called time period.

Solve the following problems:

Question 1.
A pendulum oscillates 40 times in 4 seconds. Find its time period and frequency.
Answer:
Frequency is the number of oscillations per second of a vibrating body.

The time taken to complete one oscillation (to and fro) is known, as time period.

Question 2.
The sound from a mosquito, is produced when it vibrates its wings at an average rate of 500 vibrations per second. What is the time period of the vibration?
Answer:
The time taken to complete one oscillation (to and fro) is know as time period.

Give scientific reasons:

Question 1.
Loud speakers should not be put in congested areas.
Answer:

1. The loudness or softness is indicated by the intensity of sound and sound level.
2. By putting loud speakers in congested areas, the intensity of sound being more than 100 dB will cause ill effects like temporary deafness and a prolonged exposure can lead to permanent damage.

Answer the following:

Question 1.
Why are the ceilings of concert halls curved?
Answer:
The ceilings of concert halls are curved because sound after reflection from the ceiling it reaches all the comers of the hall and is audible to each person in the hall.

Question 2.
Have you ever heard the sound of movement of hands and falling of leaves from a tree?
Answer:

1. The term infrasonic refer to sound waves below the frequencies of audible sound i.e. under 20 Hz.
2. Humans cannot hear infrasonic sound.
3. Movement of hands and falling of leaves comes below this audible range. Therefore we cannot hear these sounds.

Question 3.
How can dogs perceive in advance the signals of an impending earthquake?
Answer:
Dogs can hear sounds upto about 65,000 Hz. That’s why dogs can receive ultrasonic sound signals produced by the vibration of the earth and start barking in advance before the actual earthquake is felt.

Question 4.
State the uses of Ultrasonic sound.
Answer:
Uses of Ultrasonic sound are:

1. To clean delicate ornaments and the tiny parts of a watch.
2. To observe internal organs of the body.
3. To detect tumors in the brain.
4. To detect faults in a metal.
5. In RADAR systems
6. To Kill certain microbes and insects.
7. SONAR (Sound navigation and ranging) is used to locate the seabed or the position of a ship.

Use your brainpower!

Answer the following questions:

Question 1.
Will a sound be generated no matter how the ruler is kept on the table.

Answer:

1. No, If the ruler kept on the table is only a little part off the table, it will not vibrate with a greater force.
2. On the contrary if the ruler is kept with a larger portion off the table it will vibrate with a greater force generating louder sound.

Question 2.
Is there any correlation between the length of the free part of the ruler and the sound generated?
Answer:
Yes, vibrating ruler pushes the molecules in the air producing sound waves. More the length of free part of ruler less will be the vibrations and less will be the frequency and pitch of the sound. If the length of free part of ruler is shorter it vibrates more quickly producing sound of higher frequency and pitch.

Question 3.
If the ruler is plucked while it is held with 25 cm of it off the table, does it makes any sound? If there is no sound, look for the reason why it is so?
Answer:
No, the ruler vibrates very slowly, which has frequency which is not audible.

Question 4.
What would be the difference perceived between hearing only two pupils in the class talking to each other and all the children talking to one another at the same time?
Answer:

1. When two pupils talk to each other, the sounds of two frequencies produced can be heard clearly.
2. When all the children talk to one another sounds of many frequencies produced can not be heard clearly.
3. Sound level will be more creating loud noise.

7th Std Science Questions And Answers:

• Cell Structure and Micro-organisms Class 7 Questions And Answers
• The Muscular System and Digestive System in Human Beings Class 7 Questions And Answers
• Changes – Physical and Chemical Class 7 Questions And Answers
• Elements, Compounds and Mixtures Class 7 Questions And Answers
• Materials We Use Class 7 Questions And Answers
• Natural Resources Class 7 Questions And Answers
• Effects of Light Class 7 Questions And Answers
• Sound: Production of Sound Class 7 Questions And Answers
• Properties of a Magnetic Field Class 7 Questions And Answers
• In the World of Stars Class 7 Questions And Answers

Balbharti Maharashtra State Board Class 6 Science Solutions Chapter 12 Simple Machines Notes, Textbook Exercise Important Questions and Answers.

Std 6 Science Chapter 12 Simple Machines Question Answer Maharashtra Board

Class 6 Science Chapter 12 Simple Machines Question Answer Maharashtra Board

1. Classify the following as a lever, a pulley and an inclined plane:
(A wedge, a needle, a staircase, a slide, the wheel of a flagpole, nutcrackers, scissors, an opener, an axe, a crane, a knife)

Question a.
Classify the following as a lever, a pulley and an inclined plane:
(A wedge, a needle, a staircase, a slide, the wheel of a flagpole, nutcrackers, scissors, an opener, an axe, a crane, a knife)
Answer:

Inclined plane	Pulley	Lever
Wedge	Wheel of flagpole	Nutcracker
Needle	Crane	Scissors
Staircase		Opener
Slide
Axe
Knife.

2. Fill in the blanks using the proper word and complete the statements.

Question a.
The ………….. in the centre, the ………….. on one side and the on the ………….. other side make a lever of the first order.
Answer:
Fulcrum, load and effort

Question b.
The ………….. in the centre, the ………….. on one side and the ………….. on the other side make a lever of the second order.
Answer:
Load, fulcrum, effort

Question c.
The ………….. in the centre, the ………….. on one side and the ………….. on the other side make a lever of the third order.
Answer:
Effort, fulcrum, load

3. Which machines will you use to do the following work? Write their types.

Question a.
To remove the lid of a tin. Opener Lever of the second order
Answer:

• Work: To remove the lid of a tin.
• Machine: Opener
• Machine: Lever of the second order

Question b.
To lift bricks to the top of a tall building Crane Complex machine
Answer:

• Work: To lift bricks to the top of a tall building
• Machine: Crane
• Machine: Complex machine

Question c.
To cut vegetable Knife Wedge – Simple machine
Answer:

• Work: To cut vegetable
• Machine: Knife
• Machine: Wedge – Simple machine

Question d.
To draw water from a well Pulley Simple machine
Answer:

• Work: To draw water from a well
• Machine: Pulley
• Machine: Simple machine

Question e.
To hold a papad for roasting it. A pair of tongs Lever of the third order
Answer:

• Work: To hold a papad for roasting it.
• Machine: A pair of tongs
• Machine: Lever of the third order

4. Write the answers to the following questions in your own words. 

Question a.
What is meant by a simple machine?
Answer:

1. Machines which have only one or two parts and a simple and easy structure are simple machines.
2. Example: the bottle opener, nail cutter.
3. Simple machines can be handled easily.
4. We use many simple machines in our day to day life.

Question b.
Mention the advantages of using a machine.
Answer:

1. Machines, simple or complex, are used to get more work done in less time and with less effort.
2. Machines are used to accomplish certain tasks more easily.
3. Use of simple or complex machines depends upon the task to be carried out and the time and the efforts required to do it.

Question c.
What is meant by a complex machine?
Answer:

1. Complex machines have many parts which carry out many processes for completing a task.
2. For this purpose the parts are joined to one another.
3. Therefore, these machines are called complex machines.
4. Some of the parts of such complex machines are actually simple machines.
5. The structure of complex machine is complicated.

Question d.
What is a lever? How is the order of the lever determined?
Answer:

1. Lever is a simple machine made up of 3 parts: Load, effort and fulcrum.
2. Order of the lever are determined on the position of the effort, the fulcrum and the load.

5. Why is this so?

Question a.
Traveller’s bags have wheels.
Answer:

1. Combination of wheel and axle is a simple machine.
2. When the axle starts rotating due to force applied, the wheel fitted to it also starts rotating.
3. This makes easier for travellers to carry heavy load.
4. Instead of lifting heavy bag, to drawing it on wheels require less energy. Therefore, traveller’s bag have wheels.

Question b.
Machines have to be maintained.
Answer:

1. Parts of machines rub against one another when they are used.
2. Soiled, dusty parts create more friction. Some parts are affected by the weather, rust and corrosion.
3. Machines get damaged or become useless due to such wear and tear. Hence to avoid this, machines should be maintained properly to keep them in good working condition.

Question c.
A bicycle is said to be a complex machine.
Answer:

1. Bicycle has a complicated structure.
2. Bicycle has many parts which carry out many processes for completing a task.
3. Many parts of bicycle such as pedals, wheels, axle, handle are actually simple machines.
4. The parts of a bicycle are joined to one another – making it a complex machine.

6. Name the levers mentioned in the following passage. Identify the fulcrum, load and effort of each and say which type of lever it is.

Ravi and Savita sit on a sea-saw in a garden. In the mean time, a gardener is trimming trees in the garden. He puts the leaves and other garbage in the wheelbarrow. Later, Ravi gets thirsty and he buys lemon sherbet. The sherbet seller cuts the lemon and squeezes it using a lemon squeezer. He puts small pieces of ice in the glass with the help of the tongs.

Question a.
Name the levers mentioned in the following passage. Identify the fulcrum, load and effort of each and say which type of lever it is.

Ravi and Savita sit on a sea-saw in a garden. In the mean time, a gardener is trimming trees in the garden. He puts the leaves and other garbage in the wheelbarrow. Later, Ravi gets thirsty and he buys lemon sherbet. The sherbet seller cuts the lemon and squeezes it using a lemon squeezer. He puts small pieces of ice in the glass with the help of the tongs.
Answer:
Levers:

1. See – saw – lever of the first order.
   Load – fulcrum – effort.
2. Wheelbarrow – lever of the second order.
   Fulcrum – load – effort.
3. Lemon squeezers – lever of the second order.
   Fulcrum – load – effort.
4. Tongs – lever of the third order.
   Fulcrum – effort – load.

Activity:

Question 1.
Make a list of the various machines used in your home and neighborhood and write their types.

Question 2.
Go to a bicycle repair shop, observe how a bicycle is repaired, and note down the information.

Class 6 Science Chapter 12 Simple Machines Important Questions and Answers

Fill in the blanks.

Question 1.
Simple machines can be handled ………….. .
Answer:
easily

Question 2.
The structure of complex machine is ………….. .
Answer:
complicated

Question 3.
The more gradual the the ………….. lesser is the we bear. But, such an inclined plane is ………….. .
Answer:
slope, weight, longer

Question 4.
The steeper the ………….. , the ………….. is the inclined plane. But we have to bear a …………. weight.
Answer:
slope, shorter, greater

Question 5.
A screw is like a rolled up inclined plane made of an ………….. strip.
Answer:
iron

Question 6.
A wedge is used for ………… an object into two pieces or to ………….. the objects stuck together.
Answer:
breaking, separate

Question 7.
A farmer uses a strong …………. to remove the big stone bogged down in the farm.
Answer:
crow-bar

Question 8.
A device with a grooved wheel and thread designed to lift weights is called a …………. .
Answer:
pulley

Question 9.
When we use a pulley, force is applied in the downward direction for lifting the weight in an …………. direction.
Answer:
upward

Question 10.
Combination of an axle and a wheel is a …………. machine.
Answer:
simple

Question 11.
A needle and a nail are also kind of …………. .
Answer:
wedge

Question 12.
Machines are covered when not in use to prevent …………. settling on them.
Answer:
dust

Question 13.
In Archimedes’ screw, the pipe was placed at an angle of …………. with one end inside the …………. and the rod resting on a …………. .
Answer:
45°, water, flat surface.

Match the columns:

Question 1.

Column ‘A’	Column ‘B’
1. Pair of Scissors	a. Third order of lever
2. Tongs	b. Second order of lever
3. Opener	c. First order of lever

Answer:

Column ‘A’	Column ‘B’
1. Pair of Scissors	c. First order of lever
2. Tongs	a. Third order of lever
3. Opener	b. Second order of lever

Question 2.

Column ‘A’	Column ‘B’
1. Inclined plane	a. Needle
2. Pulley	b. Screw
3. Wedge	c. Crane

Answer:

Column ‘A’	Column ‘B’
1. Inclined plane	b. Screw
2. Pulley	c. Crane
3. Wedge	a. Needle

State whether the following statements are ‘true’ or ‘false’.

Question 1.
Lever helps big vehicle to climb up and down the mountain easily.
Answer:
False

Question 2.
Combination of wheel and axle is a simple machine.
Answer:
True

Question 3.
In pulley, force can be applied in upward direction.
Answer:
False

Question 4.
Screw is an example of wedge.
Answer:
False

Question 5.
In Archimedes screw, the rod rests on flat surface.
Answer:
True

Question 6.
A slanting plank is used to lift a weight.
Answer:
True

Question 7.
A winding road or ghat is an example of lever of first order.
Answer:
False

Answer the following questions in one sentence.

Question 1.
What is a machine?
Answer:
Devices which are used to get more work done in less time and less effort are called machines.

Question 2.
What is a simple machine?
Answer:
Machines which have only one or two parts and a simple and easy structure are called simple machines.

Question 3.
What is a complex machine?
Answer:
Some machines have many parts and they carry out many processes for completing a task. For this purpose, the parts are joined to each other. They are called complex machines.

Question 4.
List the properties of simple machines.
Answer:
Properties of simple machine are:

1. They are made up of only one or two parts.
2. They have a simple and easy structure.
3. They can be handled easily.
4. There are less chances of simple machines breaking down or getting damaged.

Question 5.
List properties of complex machines.
Answer:
Properties of complex machine are:

1. These machines have many parts to carry out many processes.
2. The parts are joined to one another.
3. The structure of complex machines is complicated.
4. Some parts of complex machines are actually simple machines.

Question 6.
What is an inclined plane?
Answer:
A slanting plank which is used to lift a weight on which we bear less weight and lifting becomes easier is an inclined plane.

Question 7.
What is a screw?
Answer:
A screw is like a rolled up inclined plane made up of iron strip.

Question 8.
What is a wedge?
Answer:
A wedge is used for breaking an object into two pieces or to separate objects stuck together.

Question 9.
State examples of wedges.
Answer:
An axle, a knife, a chisel, a needle and a nail are different kinds of wedges.

Question 10.
What is a lever?
Answer:
A lever is a machine made up of 3 parts: effort, load and fulcrum.

Question 11.
What is a fulcrum?
Answer:
The support at which the rod of a lever is rested is called fulcrum of a lever. The lever rotates about the fulcrum.

Question 12.
What is a load?
Answer:
The weight lifted by a lever or the force against which the lever acts is called a load.

Question 13.
What is a load arm?
Answer:
The arm of the lever from the fulcrum to the load is called a load arm.

Question 14.
What is an effort?
Answer:
The force applied on the other end of the rod to lift the load is called an effort.

Question 15.
What is an effort arm?
Answer:
The part of the lever from the fulcrum to the effort is called an effort arm.

Question 16.
What is lever of the first order?
Answer:
The fulcrum is in the centre, the load is at one end while effort is at other end.

Question 17.
What is lever of the second order?
Answer:
The load is in the centre, the fulcrum on one side, and the effort on the other side.

Question 18.
What is lever of the third order?
Answer:
The effort is in the centre, the fulcrum on one side, and the load on the other side.

Question 19.
What is a pulley?
Answer:
A pulley is a device with a grooved wheel and thread designed to lift weights.

Question 2.
How does a pulley help us?
Answer:
If we use a pulley, force can be applied in the downward direction for lifting the weight in an upward direction. It is convenient and easy.

Give scientific reasons:

Question 1.
We use many simple machines in our day-to-day life.
Answer:
Simple machines can be handled easily and there are less chances of these machines breaking down or getting damaged. Hence, we use many simple machines in our day-to-day life.

Question 2.
Less force is required to fit a screw than to hammer a nail.
Answer:

1. A screw is like a rolled-up inclined plane of an iron strip.
2. When a screw is fitted in wood it goes in as if it is going down an inclined plane.
3. Therefore, less force is required to fit a screw than hammer a nail.

Question 3.
Big vehicles easily climb up and down the mountains than a pathway.
Answer:
A winding road or ghat that goes up a mountain is like an inclined plane wrapped around the mountain. It helps big vehicles to climb, up and down the mountain easily.

Question 4.
Oil or lubricant is released between parts of machine.
Answer:
Oil or lubricant is released between parts that rub against each other so that there is less friction between them and wearing is reduced.

Question 5.
Machines are covered when not in use.
Answer:
Machines are covered when not in use to prevent dust settling on them.

Question 6.
How are machines protected from the effect of weather?
Answer:
To prevent the effect of weather, metallic parts in a machine are painted externally and the machines are always kept dry.

Draw the neat and labelled diagram of following:

Question 1.
The screw as an inclined plane.
Answer:

Question 2.
Archimedes’ screw
Answer:

Observe the following diagram and identify the order of lever.

Question 1.
Removing the lid.
Answer:

Question 2.
Picking up an object.
Answer:

Question 3.
Lifting a paper weight.

Answer:

1. Lever of the second order
2. lever of third order
3. Level of first order.

Answer each of the question in brief:

Question 1.
With the help of the diagram explain lever of the 1st, 2nd, 3rd order.
Answer:
1. Lever of the First order: The fulcrum is in the centre, the load is at one end, while the effort is at the other end. e.g. scissors

2. Lever of the Second order: The load is in the centre, the fulcrum on one side, and the effort on the other side. e.g. lid opener

3. Lever of the Third order: The effort is in the centre, the fulcrum on one side, and the load on the other side. e.g. Tongs

Question 2.
How can machines be maintained?
Answer:

1. To maintain machines, all its parts are wiped clean.
2. Oil or lubricant is released between parts that rub against each other.
3. Machines are covered, painted externally and always kept dry.

Question 3.
What is an inclined plane? Explain longer and shorter inclined plane.
Answer:

1. A slanting plank used to lift a weight, is called an inclined plane. Because of inclined plane we will experience less weight and weight lifting become easier.
2. Longer inclined plane: When the inclined plane is longer, the slope is more gradual and lesser is the weight we bear.
3. Shorter inclined plane: When the inclined plane is shorter, the slope is steeper and greater is the weight we bear.

Question 6.
Explain the working of a giant wheel.
Answer:

1. The giant wheel is fitted to a rod at its centre. This rod is called an axle.
2. When the axle starts rotating with the help of electricity the wheel fitted to it starts rotating.
3. This combination of an axle and a wheel is a simple machine.

Observe and discuss:

Question 1.
Name the devices and discuss how they help.

Answer:

1. Needle and thread – Stitching of clothes
2. Wheelbarrow – To carry materials.
3. Opener – To open the lids of bottles.
4. Pulley – To lift bucket
5. Nail cutter – To cut nails
6. Axe – To cut wood into small pieces

Can you tell?

Question 1.
Observe the machines shown in the following pictures. For what purposes are they used? Can you name some other machines of this kind?

Answer:

1. Mixer grinder – To grind the foodstuffs
2. Scooter – To ride and reach places
3. Bicycle – To ride and reach places
4. Sewing machine – To stitch clothes
5. Wheel chair – Specially designed for handicapped patients to move around.

Question 2.
Compare the pathway and a road, available to climb the mountain, the time and strength and your convenience, required to reach the mountain top.
Answer:
We can reach the mountain top by climbing the pathway early than by the road. The time required is less but the strength required is more. The road is easy to walk and more time consuming.

Question 3.
If the point of a needle or the edge of a knife become blunt, then the needle does not penetrate the cloth and the knife does not cut into the fruit. Why is this so?
Answer:
The tip of the needle or the edge of a knife becomes blunt due to regular use. Both the knife and the needle lose their sharpness.

Use your brain power!

Question 1.
Which task can be done using a lever?
Answer:
Task such as using a nut cracker, cutting paper with scissors, can be done using a lever.

Question 2.
Some machines we use in our day to day life are shown in picture. What is the type in each of these?

Answer:

• Wheelbarrow – Lever of the third order
• Pair of tongs – Lever of the first order
• See – saw – Lever of the first
• order Cutter – Lever of the second lever
• Pair of Scissors – Lever of the first order.

Question 3.
When the pedal of the bicycle is rotating, the wheel starts rotating. How does this happen?
Answer:
Pedals of the bicycle are connected to the wheels through the axle, when the axle starts rotating, the wheels also start rotating.

Question 4.
Examples of pulley.
Answer:

1. A simple pulley is used to hoist a flag, to draw water from a well.
2. The crane which is used to lift heavy loads is an example of application of pulleys and levers working together.

6th Std Science Questions And Answers:

• Work and Energy Class 6 Questions And Answers
• Simple Machines Class 6 Questions And Answers
• Sound Class 6 Questions And Answers
• Light and the Formation of Shadows Class 6 Questions And Answers
• Fun with Magnets Class 6 Questions And Answers
• The Universe Class 6 Questions And Answers

Balbharti Maharashtra State Board Class 6 Science Solutions Chapter 3 Diversity in Living Things and their Classification Notes, Textbook Exercise Important Questions and Answers.

Std 6 Science Chapter 3 Diversity in Living Things and their Classification Question Answer Maharashtra Board

Class 6 Science Chapter 3 Diversity in Living Things and their Classification Question Answer Maharashtra Board

1. Match the pairs.

diversity in living things and their classification class 6 exercise Question 1.

Column ‘A’	Column ‘B’
1. Amphibians	a. A monkey
2. Vertebrates	b. A snake
3. With scales	c. A frog

Answer:

Column ‘A’	Column ‘B’
1. Amphibians	c. A frog
2. Vertebrates	a. A monkey
3. With scales	b. A snake

2. Who is the odd one out?

Question a.
Fungus, mushroom, chrysanthemum, spirogyra
Answer:
Chrysanthemum (only flowering plants)
or
Spirogyra (only aquatic plant)

Question b.
Mango, banyan, palm, chickpea
Answer:
Chickpea (shrub, others are not)
or
Palm (tall tree without any branches, others have branches)

Question c.
Grape, orange, lemon, hibiscus
Answer:
Grape (only creeper, others are not)
or
Hibiscus (flower, others are fruits)

Question d.
Sunflower, banyan, jowar, bajra
Answer:
Banyan (perinnial, others are not)

Question e.
Guava, radish, carrot, beetroot
Answer:
Gauva (fruit, others are roots)

Question f.
Deer, fish, man, worms
Answer:
Worms (invertebrate, others are not)
or
Fish (aquatic animal, others are terristrial animals

3. What is the difference?

Question a.
Flowering plant and Non-flowering plant
Answer:

Flowering plant	Non-flowering plant
1. Plants that bear flowers are called flowering plants.	1. Plants that do not bear flowers are called non­flowering plants.
2. They have roots, stems and leaves.	2. They may not have roots, stems or leaves.
e.g. Rose, sunflower, lotus	e.g. Pine, fern, algae

Question b.
A Tree and a Shrub
Answer:

Tree	Shrub
1. They have branches at some height above the ground.	1. They give out branches close to the ground.
2. They grow very tall compared to shrubs.	2. They grow upto 2 to 3 metres in height.
3. They have strong and hard stems.	3. They have thick hard stems.
e.g. Mango tree, banyan tree	e.g. Hibiscus, oleander

Question c.
Vertebrates and Invertebrates
Answer:

Vertebrates	Invertebrates
1. They have vertebral column.	1. They do not have vertebral column.
2. The brain is well developed.	2. The brain if present may not be developed.
e.g. Human, dog, fishes etc.	e.g. earthworm, insects etc.

4. True or false?

Question a.
The snail is an aquatic animal.
Answer:
False

Question b.
Amphibians can live in air and in water.
Answer:
False

Question c.
The function of the brain is well developed in vertebrate.
Answer:
True

Question d.
The amoeba is a multicellular animal.
Answer:
False

5. Write two names of each. 

Question a.
A flowering plant
Answer:
Rose, hibiscus

Question b.
A non-flowering plant
Answer:
Fern, algae

Question c.
A tree
Answer:
Mango, banyan

Question d.
A shrub
Answer:
Oleander, hibiscus

Question e.
A creeper
Answer:
Pumpkin, watermelon

Question f.
An annual plant
Answer:
Jowar, sunflower

Question g.
A biennial plant
Answer:
Carrot, beetroot

Question h.
A perennial plant
Answer:
Mango, gulmohar

6. Write answers to the following. 

Question a.
What are the parts of a plant?
Answer:
The parts of a plant are: root, stem, leaves, flowers, fruit and seed.

Question b.
What are the functions of root?
Answer:
The functions of root are:

1. The root hold the soil firmly and anchor the plant.
2. They absorb water, salt and minerals from the soil and transport it to stem.
3. Some roots store food. e.g. Carrot, radish.

Question c.
Why is it necessary to classify living things?
Answer:

1. There is a great diversity in living things- both plants and animals on the earth.
2. In order to identify them and to study their characteristics, systematic classification is necessary.

Question d.
What are the criteria used to classify living things?
Answer:
Following are the criteria used to classify living things:
a. Plants:

• Mode of nutrition.
• Similarities and differences in structure.
• Presence of flowers or not.
• Period of life cycles.
• Habitat.

b. Animals:

• Cell structure.
• Presence of vertebral column.
• Method of reproduction.
• Habitat.

Question e.
Tell some characteristics of creepers.
Answer:
The characteristics of creepers are:

1. The stem of a creeper is very flexible, soft and green and need support to climb.
2. Some climbers spread on the ground, e.g. Pumpkin
3. Some have aerial roots, e.g. Money plant
4. Some climbers develop tendrils, e.g. Cucumber

Question f.
Explain the characteristics of herbs with examples.
Answer:

1. Herbs grow 1 to 1.5 m tall.
2. Their stem is green and quite flexible.
3. They may live for a few months or upto two years, e.g. Tulsi, oregano, etc.

Question g.
How is the body of animals protected?
Answer:
Body of animals are protected by special covering such as skins, feathers, scales, hair fur, etc.

Question h.
On the basis of which criteria will you classify plants and animals?
Answer:

7. Draw figures. 

Question a.
Draw the figure of a plant to show the parts, namely, the root, stem and leaves in it.
Answer:

Activity:

Question 1.
Visit a plant nursery and classify the plants there.

Question 2.
Visit a zoo and obtain information about the diversity in animals.

Question 3.
Write an essay on diversity in plants.

Question 4.
Collect seeds of various plants during summer and throw them in open spaces (fallow land, moorland, hill, etc.) during the rainy season.

Class 6 Science Chapter 3 Diversity in Living Things and their Classification Important Questions and Answers

Fill in the blanks:

Question 1.
Plants that can prepare their own food are called ………….. plants.
Answer:
autotrophic

Question 2.
Pitcher plants are ………….. .
Answer:
insectivorous

Question 3.
The ………….. is an important means of reproduction.
Answer:
flower

Question 4.
Animals that lay eggs are ………….. animals.
Answer:
oviparous

Question 5.
Animals that can live on land as well as water are called ………….. .
Answer:
amphibians

Choose the correct alternative:

Question 1.
The ………….. is a perennial.
(a) beetroot
(b) gulmohar
(c) grass
Answer:
(b) gulmohar

Question 2.
The sunflower is a / an ………….. plant.
(a) annual
(b) biennial
(c) perennial
Answer:
(a) annual

Question 3.
Cactus is a ………….. plant.
(a) land
(b) water
(c) desert
Answer:
(c) desert

Question 4.
The …………….. is a unicellular animal.
(a) cockroach
(b) snail
(c) paramoecium
Answer:
(c) paramoecium

Question 5.
Hen is a …………….. animal.
(a) oviparous
(b) viviparous
(c) none of above
Answer:
(b) oviparous

Question 6.
Earthworm is a / an ……………. animal.
(a) vertebrate
(b) invertebrate
(c) unicellular
Answer:
(b) invertebrate

True or False:

Question 1.
The pods of beans and peas are actually fruits.
Answer:
True

Question 2.
Fungus is heterotrophic.
Answer:
True

Write two names of each.

Question 1.
An invertebrate animal
Answer:
Earthworm, cockroach

Question 2.
An oviparous animal.
Answer:
Hen, sparrow

Distinguish between:

Question 1.
Autotrophic plant and Heterotrophic plant
Answer:

Autotrophic plant	Heterotrophic plant
1. They can produce their own food.	1. They cannot produce their own food. They depend on other things for their food.
2. They are green in colour.	2. They are non­green in colour.
e.g. Periwinkle, pomegranate etc.	e.g. Dodder, loranthus etc

Classify as directed.

Question 1.
Into annual, biennial, perennial
Sunflower, carrot, bajra, mango, jowar, oleander, beetroot, coconut
Answer:

Annual	Biennial	Perennial
Sunflower	Carrot	Mango
bajra	beetroot	oleander
jowar		coconut

Question 2.
Into vertebrates and invertebrates
Fish, cat, earthworm, snail, hen, cockroach
Answer:

Vertebrates	Invertebrates
Fish	Earthworm
cat	snail
hen	cockroach

Define. 

Class 6 Science Chapter 3 Diversity In Living Things and Their Classification Question 1.
Unicellular animal
Answer:
Animals which have a single cell body performing all functions, are called unicellular animals, e.g. Amoeba

Diversity In Living Things And Their Classification Exercise Question 2.
Multicellular animals
Answer:
Animals which have many cells in their body, are called multicellular animals, e.g. Cat

Diversity In Living Things and Their Classification Question 3.
Vertebrates
Answer:
Animals with vertebral column are called vertebrates, e.g. Man

Question 4.
Invertebrate animals
Answer:
Animals without vertebrate column are called invertebrate animals, e.g. Earthworm

Question 5.
Oviparous animals
Answer:
Animals which lay eggs and hatch them are called oviparous animals, e.g. Hen

Question 6.
Viviparous animals
Answer:
Animals which give birth to their young ones are called viviparous animals, e.g. Dog

Answer the following:

Question 1.
Give the functions of:
Answer:
a. Stem:
1. The stem gives support to the other parts of the plant.
2. The stem carries out the function of production, conduction and storage of the food.
3. In some cases it stores food.
b. Leaves: They play an important role in the production of food.
c. Flowers: The flowers are reproductive organ of plant.
d. Fruits: Fruits have seeds which give rise to new plant.
e. Seeds: From the seeds arise new plants.

Answer the following in short.

Question 1.
What type of plants are toolstools and mushrooms?
Answer:
Toolstools and mushrooms are heterotrophs.

Question 2.
What type of plant is a fig?
Answer:
Fig is a tree.

Question 3.
Do ferns, algae and money plant bear flowers?
Answer:
Ferns, algae and money plants do not bear flowers. They are non-flowering plants.

Question 4.
Which is the largest flower and where is it found?
Answer:
Rafflesia Arnoldi is the world’s largest flower. It is found in Indonesia.

Question 5.
Where does pomegranate grow?
Answer:
Pomegranate is a shrub which grows on land in soil.

Question 6.
Where do bulrushes and railroad creepers grow?
Answer:
Bulrushes is a water plant and railroad creepers grow along the ground.

Question 7.
Where does lotus grow?
Answer:
Lotus grows in water.

Question 8.
Where does the dodder plant grow?
Answer:
Dodder is a parasitic plant and grows on other plants.

Question 9.
Why does water hyacinth float?
Answer:
The stem of water hyacinth is filled with air and its leaves are specially modified, which helps it to float in water.

Question 10.
Why is the stem of a cactus plant fleshy?
Answer:
Cactus is a desert plant. As there is a shortage of water, cactus stores water in its stem and hence, stem of cactus is fleshy.

Question 11.
Which spheres of the earth do living things exist?
Answer:
Living things exists in all three spheres of earth, i.e. Atmosphere, lithosphere and hydrosphere.

Question 12.
Are the plants and animals that you have seen all alike?
Answer:
No. They are all of different types.

Question 13.
What are the similarities between a mango, a banyan and a tamarind tree?
Answer:
They are tall, big and perennial plants.

Question 14.
What are the similarities between the hibiscus, oleander and lantana plants?
Answer:
They are shorter and smaller than trees.

Question 15.
What are the similarities between fenugreek and periwinkle plants?
Answer:
They are smaller and shorter than trees and shrubs.

Question 16.
Have you seen vines like the pumpkin, the railroad creeper, kavali, watermelon or the grapvine? How do they grow?
Answer:
They have very soft, green and flexible stem. They grow with the help of a support.

Question 17.
For how many years do crops like bajra, wheat, corn, radish, marigold live?
Answer:
They live for about one year.

Question 18.
To which part of plants are butterflies and insects attracted?
Answer:
Butterflies and insects are attracted towards the flower of the plants.

Question 19.
What is the chain of bones in the centre of our back called?
Answer:
A vertibral column.

6th Std Science Questions And Answers:

• Natural Resources – Air, Water and Land Class 6 Questions And Answers
• The Living World  Class 6 Questions And Answers
• Diversity in Living Things and their Classification Class 6 Questions And Answers
• Disaster Management Class 6 Questions And Answers
• Substances in the Surroundings – Their States and Properties Class 6 Questions And Answers
• Substances in Daily Use Class 6 Questions And Answers
• Nutrition and Diet Class 6 Questions And Answers
• Our Skeletal System and the Skin Class 6 Questions And Answers
• Motion and Types of Motion
• Force and Types of Force Class 6 Questions And Answers

Balbharti Maharashtra State Board Class 7 Science Solutions Chapter 6 Measurement of Physical Quantities Notes, Textbook Exercise Important Questions and Answers.

Std 7 Science Chapter 6 Measurement of Physical Quantities Question Answer Maharashtra Board

Class 7 Science Chapter 6 Measurement of Physical Quantities Question Answer Maharashtra Board

1. Write answers to the following questions in your own words:

Question a.
Why is the weight of the same object different on different planets?
Answer:
The weight of the same object is different on different planets because weight depends on the gravitational force of the planet and gravitational force on every planet is different so the weight also differs from planet to planet.

Question b.
What precautions will you take to make accurate measurements in day-to-day affairs?
Answer:
Following precautions will be taken to make accurate measurements in day to day affairs:

1. The balance should carry the stamp of standardisation by the department of weights and measures.
2. Balance should be stable and the pointer of the balance should be upright.
3. The underside of the pan should not be tampered with any other weight or layers of other metal.
4. The weight should be made of metal.

Question c.
What is the difference between mass and weight?
Answer:

Mass	Weight
1. The amount of matter present in a substance is called mass.	1. The gravitational force that acts on this mass is called its weight.
2. It is a scalar quantity.	2. It is a vector quantity.
3. Mass remains same everywhere on the earth.	3. Weight changes from place to place on the ‘        earth.

2. Who is my companion? 

Class 7 Science Chapter 6 Measurement Of Physical Quantities Exercise Question 1.

Column ‘A’	Column ‘B’
1. Velocity	a. Litre
2. Area	b. Kilogram
3. Volume	c. metre/second
4. Mass	d. kilogram/cubic metre
5. Density	e. square metre

Answer:

Column ‘A’	Column ‘B’
1. Velocity	c. metre/second
2. Area	e. square metre
3. Volume	a. Litre
4. Mass	b. Kilogram
5. Density	d. kilogram/cubic metre

3. Explain giving examples. 

Question a.
Scalar quantity:
Answer:
A quantity that can be completely expressed by its magnitude alone is called a scalar quantity, e.g. length, breadth, area, mass, temperature, density, time, work. In all these examples a value with a unit is used to express quantities. Thus, we say that the length of a tunnel is 2 km.

Question b.
Vector quantity:
Answer:
The quantity that is expressed completely only.’ v when magnitude and direction are both given is called a vector quantity. Displacement, velocity are vector quantities e.g. a displacement of 20 km towards north, the aeroplane flying at a velocity of 500 km/hr towards Mumbai.

4. Explain, giving examples, the errors that occur while making measurements.

Question a.
Explain, giving examples, the errors that occur while making measurements.
Answer:
Major causes of errors in measurement are:

1. Not using the appropriate device.
2. Not using the device properly.

Example: While buying things at grocery shops and the vegetable market remember to look out for the following:

• The balance should carry the stamp of standardisation by the department of weights and measures.
• Balance should be stable. The pointer of the balance should be upright.
• No changes should be done on the underside of the pan of the balance.
• Weight should be made up of metals and it has to be standardized.

5. Give reasons:

Question a.
It is not proper to measure quantities by using body parts as units.
Answer:
It is not proper to measure quantities by using body parts as units because length of the body parts changes from person to person, so accurate measurement can not be found with the body parts as units.

Question b.
It is necessary to get the weights and measures standardized at regular intervals.
Answer:
It is necessary to get the weights and measures standardized at regular intervals because of that accurate weight and measurement can be taken. Errors will be avoided.

6. Explain the need for accurate measurement and the devices to be used for that.

Question a.
Explain the need for accurate measurement and the devices to be used for that.
Answer:

1. Measurement of substances that are precious or of great importance and used in very small quantities is done meticulously and accurately.
2. Due to advancements in technology, devices that measure very small magnitudes of quantities like distance, mass, time and temperature are available now.
3. e.g. distance and time in connection with very important sports competitions, mass of gold, body temperature etc.
4. Devices to be used for this are thermometer, digital balance (Analytical balance) etc.

Project:

Class 7 Science Chapter 6 Measurement Of Physical Quantities Question 1.
Collect information about various physical quantities used in day-to-day life and the devices used for their measurement.

Class 7 Science Chapter 6 Measurement of Physical Quantities Important Questions and Answers

Fill in the blanks:

Std 7 Science Chapter 6 Measurement Of Physical Quantities Question 1.
The amount of matter present in a substance is called ………………. .
Answer:
mass

Measurement Of Physical Quantities Class 7 Exercise Question 2.
…………. is the qualitative measure of the inertia of an object.
Answer:
mass

6. Measurement Of Physical Quantities Question 3.
The larger the mass, the ……………. is the inertia.
Answer:
greater

6.Measurement Of Physical Quantities Question 4.
Mass is a …………… quantity.
Answer:
scalar

Physical Quantities And Measurement Class 7 Question 5.
…………… does not change from place to place anywhere in the world.
Answer:
mass

Measurement Of Physical Quantities Class 7 Question 6.
The gravitational force that acts on a mass is called its ……………. .
Answer:
weight

6 Measurement Of Physical Quantities Question 7.
Wright is a …………… quantity.
Answer:
vector

Question 8.
System International (SI) is also called ………….. .
Answer:
metric system

Question 9.
In Egypt in ancient times, the distance from a man’s elbow to the tip of his middle finger was called a ………… .
Answer:
cubit

Question 10.
Gold was weighed in a unit called …………… .
Answer:
gun

Who is my companion?

Question 1.

Column ‘A’	Column ‘B’
1. Gold	a. Hour glass
2. Time	b. Vector
3. Distance	c. Gunj
4. Weight	d. Cubit

Answer

Column ‘A’	Column ‘B’
1. Gold	c. Gunj
2. Time	a. Hour glass
3. Distance	d. Cubit
4. Weight	b. Vector

Say whether true or false. Correct and rewrite the false statements:

Question 1.
The standards of the six fundamental units are kept in the National Physical Laboratory at New Delhi.
Answer:
True

Question 2.
Matter has a natural tendency to resist a change in its state, which is called inertia.
Answer:
True

Question 3.
Weight and mass are both equal quantities.
Answer:
False. Weight and mass are both different quantities

Question 4.
Work is a vector quantity.
Answer:
False. Work is a scalar quantity

Question 5.
Velocity is a scalar quantity.
Answer:
False. Velocity is a vector quantity

Question 6.
Unit of time in both the systems is second.
Answer:
True

Question 7.
Unit of mass in C.G.S. system is kilogram
Answer:
False. Unit of mass in C.G.S. system is gram

Question 8.
Symbol of unit of second is sec.
Answer:
False. Symbol of unit of second is ‘s’

Question 9.
1 cubic foot means 28.317 ml
Answer:
False. 1 cubic foot means 28.317 litres.

Question 10.
Vector quantity requires magnitude only.
Answer:
False. Vector quantity required magnitude and direction both.

Give scientific reasons:

Question 1.
Weight of our body on the moon is less than that on the earth.
Answer:

1. Gravitational power of moon is less than the earth.
2. Weight depends on the gravitational power of that place.
3. Since the gravitational power of the moon is less than that of the earth, the weight on moon is less than that on the earth.

Question 2.
Mass is a scalar quantity
Answer:
Mass is a scalar quantity because it can be completely expressed by its magnitude alone, so it is scalar quantity.

Question 3.
Weight is a vector quantity.
Answer:
Weight can be expressed completely only when magnitude and direction are both given so weight is a vector quantity.

Distinguish between the following:

Question 1.
Scalar quantity and Vector quantity
Answer:

Scalar quantity	Vector quantity
1. A quantity that can be completely expressed by its magnitude alone is called a scalar quantity.	1. The quantity that is expressed completely only when magnitude and direction are both given is called a vector quantity.
2. e.g. mass, length, area, breadth, density, time, work etc.	2. e.g. velocity displacement

Question 2.
M.K.S. system and C.G.S. system
Answer:

M.K.S. system	C.G.S. system
1. In this system distance is measured in metres, mass in kilograms and time in seconds.	1. In this system distance is measured in centimetres, mass in grams and time in seconds.
2. e.g. Unit of velocity is m/sec, Unit of area is square metre.	2. e.g. Unit of velocity is cm/sec, Unit of area is square centimetre.

Define the following:

1. Mass: The amount of matter present in a substance is called mass.
2. Inertia: Matter has a natural tendency to resist a change in its state, which is called Inertia.
3. Weight: The gravitational force that acts on the mass is called its weight.
4. Physical Quantities: The quantities in day to day life which can be measured are called physical quantities.
5. Standardization: The process of checking things against a standard measure from time to time is called standardization.

Write answers to the following questions in your own words.

Question 1.
What is an atomic clock?
Answer:
An extremely accurate type of clock which is regulated by the vibrations of an atomic or molecular system such as caesium atom or ammonia is called atomic clock. It is used to maintain standard times of countries accurately.

Answer the following questions:

Question 1.
Why would the weight of an object be; maximum at the poles and minimum at the equator?
Answer:

1. The gravitational force that acts on the mass is called the weight.
2. The earth is not exactly spherical, it flattens at the poles.
3. As the distance increases the gravitational force decreases.
4. Therefore due to reduced distance at the poles compared to the equator, the weight is maximum at the poles than equator.

Question 2.
Why is the weight of an object at a high altitude less than its weight at the sea-level?
Answer:

1. The gravitational force that acts on the mass is called the weight.
2. The gravitational force is always inversely proportional to the distance.
3. So as the distance increases between the earth and the object, the gravitational force decreases.
4. The gravitational force by which the earth attracts an object towards its centre is called weight.
5. The weight at the sea-level is higher than at higher altitude, as the object is at a greater distance at higher altitudes compared to sea-level.

7th Std Science Questions And Answers:

• The Living World: Adaptations and Classification Class 7 Questions And Answers
• Plants: Structure and Function Class 7 Questions And Answers
• Properties of Natural Resources Class 7 Questions And Answers
• Nutrition in Living Organisms Class 7 Questions And Answers
• Food Safety Class 7 Questions And Answers
• Measurement of Physical Quantities Class 7 Questions And Answers
• Motion, Force and Work Class 7 Questions And Answers
• Static Electricity Class 7 Questions And Answers
• Heat Class 7 Questions And Answers
• Disaster Management Class 7 Questions And Answers

Balbharti Maharashtra State Board Class 6 Science Solutions Chapter 13 Sound Notes, Textbook Exercise Important Questions and Answers.

Std 6 Science Chapter 13 Sound Question Answer Maharashtra Board

Class 6 Science Chapter 13 Sound Question Answer Maharashtra Board

1. Fill in the blanks with the proper words.

Question a.
The propagation of sound does not occur through a ………….. .
Answer:
vacuum

Question b.
Noise pollution is a …………… issue.
Answer:
social/serious

Question c.
The sound which is disagreeable to our ears is called …………… .
Answer:
noise

Question d.
Noise has adverse effects on our …………….. .
Answer:
health

2. What should we do?

Question a.
The silencer of a motorcycle is broken.
Answer:

1. If the silencer of a motorcycle is broken, vehicle should be immediately taken to the garage for repair.
2. If silencer is not maintained properly, it will continue making loud noise on the road while in motion, resulting in increasing noise pollution.

Question b.
A factory in the surrounding is producing continuous loud noise.
Answer:
Factories should be located at a proper distance away from residential areas. Authorities should be contacted who will control the decibel level.

3. Write the answers in your own words.

Question a.
What is meant by vibration?
Answer:
Vibration of an object is necessary for the production of sound. As long as the object vibrates, the sound is heard. When the vibration stops, the sound also stops.

Question b.
Explain with the help of practical examples how sound is propagated through solids.

Answer:

1. Singing
2. Chirping of birds
3. Bursting of crackers
4. Whispering
5. Whistling
6. Flute
7. Honking
8. Dog barking

Question c.
What is meant by noise pollution?
Answer:
Continuous noise which has ill effects is called noise pollution.

Question d.
What measures will you take to control noise pollution?
Answer:
Measures for preventing noise pollution:

1. As far as possible, we should avoid blowing horns.
2. The volume of the TV or radio in the house should be restricted to those watching the programmes.
3. Vehicles should be maintained properly to reduce the unnecessary sounds they produce.
4. Factories, airports, railway stations and bus stands should be located at the proper distance away from residential area.
5. Planting of trees helps reduce noise as trees act as a natural barrier.

4. Complete the table.

Question a.

Answer:

Nature of sound	Unpleasant	Pleasant
1. Speaking		✓
2. Whispering		✓
3. Aeroplane Sounds	✓
4. Horns of Vehicles	✓
5. Railway Engine	✓
6. Rustling of leaves		✓
7. Neighing of a horse	✓
8. Ticking of a clock		✓

Project:

Question 1.
Prepare a list of the harsh sounds mheard near your house. Write about those sounds which produce noise pollution.

Question 2.
Collect information about places where loud noise is prohibited and discuss why it is so.

Class 6 Science Chapter 13 Sound Important Questions and Answers

Fill in the blanks:

Question 1.
Some sounds are ……………… and are heard easily.
Answer:
loud

Question 2.
Some sounds are very ……………… and cannot be heard unless we listen attentively.
Answer:
soft

Question 3.
As long as the object ……………… the sound is heard.
Answer:
vibrates

Question 4.
When the vibration ……………… the sound also stops.
Answer:
stops

Question 5.
The intensity of sound is measured in a unit called ……………… .
Answer:
decibels(dB)

Question 6.
The voice box is located in our ……………… .
Answer:
throat

Question 7.
Sound travels in the form of ……………… through air, water and ……………. .
Answer:
waves, solids

Question 8.
The sound is propagated more clearly through a ……………… than through air.
Answer:
solid

Question 9.
Transmission of sound occurs at a different ……………… through different mediums.
Answer:
speed

Question 10.
Continuous noise which may have ill effects, is called noise ……………… .
Answer:
pollution

Question 11.
Some of the sounds that we enjoy can be a ……………… for others.
Answer:
nuisance

Question 12.
The vibration of an object is necessary for the ……………… of sound.
Answer:
production

Answer in one sentence.

Question 1.
List characteristics of sound.
Answer:
Sounds are soft, loud, pleasant and unpleasant.

Question 2.
What do you mean by unpleasant sounds?
Answer:
The sounds by which we get annoyed are called unpleasant sounds.

Question 3.
What do you mean by loud and soft sounds?
Answer:
The sounds which are heard easily, are loud sounds and the sounds which cannot be heard unless we listen attentively, are soft sounds.

Question 4.
Which movement is exhibited by diaphragm of a speaker and a tabla?
Answer:
Diaphragm of a speaker and a tabla exhibit rapid oscillatory motion which gives rise to vibrations.

Question 6.
What is source of the sound?
Answer:
The object due to which sound is produced is called the source of the sound.

Question 7.
What is acoustics?
Answer:
The science of sound, resonance, production, propagation and effects of sound is called acoustics.

Question 8.
What produces sound in living beings?
Answer:
The vibration of the vocal chords in our larynx or voice box produces sound.

Question 9.
On what does quality of sound depend?
Answer:
Quality of sound produced in the larynx depends upon the tautness of the vocal chords.

Question 10.
How is sound propagated?
Answer:
The sound is propagated in the form of waves through air, water or through a solid.

Question 11.
Why is sound heard more clearly through solids?
Answer:
Transmission of sound occurs at a different speed through different mediums. Transmission of sound is faster through a solid than through a liquid and gas.

Question 12.
What is noise?
Answer:
A loud sound is harsh to ears. Such sounds produce noise.

Question 13.
List the effects of very loud or continuous noise on the people.
Answer:

1. Very loud or continuous noise can cause hearing impairment.
2. This can even lead to deafness.
3. It also causes restlessness, irritability and mental exhaustion.

Question 14.
What is noise pollution?
Answer:
Continuous noise which has ill effects is called noise pollution.

Question 15.
How can we prevent noise pollution with respect to watching TV?
Answer:
The volume of the TV or radio in the house should be restricted to those watching the programmes.

Explain the terms.

Question 1.
Propagation of sound:
Answer:
Sound is said to be propagated when sound waves spread in all directions from a source of sound.

Question 2.
Medium of propagation of sound:
Answer:
The substance around a source of sound through which sound waves spread is called the medium of propagation of sound.

Question 3.
Which sounds do you hear during the recess in the school?
Answer:
During the recess in the school, we hear.

1. laughing
2. students running
3. talking loudly
4. ringing of the bell
5. stamping on the staircase
6. shouting

Question 4.
When there is silence in the classroom, close your eyes and sit quietly. Which sounds in your surroundings can you hear now?
Answer:

1. Loud: Laughing, running, talking, horn of cars, marriage procession, school band, teacher’s voice in next classroom.
2. Pleasant: P.T. teacher’s whistle, chirping of birds.
3. Unpleasant: Shouting, bell ringing, stamping on staircase, dog barking, horns of vehicles.

Question 5.
When a song is being played on a radio or a music system in the house, place your hand on its speaker. What do you feel? Put off the music. What do you feel now?
Answer:

1. When a hand is placed on the speakers of the music system, we feel vibrations on the hand.
2. When music is put off, we don’t feel any vibrations on the hand.

Question 6.
When a metal dish falls on the floor; it makes a loud noise. What do we do to stop the noise? What is the effect of that action?
Answer:
To stop the noise of metal dish falling on the floor, quickly put hand on the dish. Vibrations of the metal dish are stopped and the noise stops.

Question 7.
What is it that vibrates when the sounds of sitar, bell, water tap, and breaking of a saucer, etc. are produced?
Answer:
Strings of the sitar, tongs of the bell, water drops hitting the floor of the basin, pieces of saucers that hit the ground vibrate to produce the sounds.

Question 8.
Take a pot full of water. Strike it lightly on the rim. What do you see? Why are waves formed on the water in the pot?
Answer:

1. We see ripples on the water.
2. When we strike the rim of the pot, our striking causes vibrations. These vibrations are transferred or moved from the pot to the water. Hence, water waves/ripples are seen on the water in the pot.

Question 9.
On rubbing balloon filled with water and another filled with air, of which balloon do we hear a clear or sound?
Answer:
We hear a clearer sound of the water balloon.

Question 10.
If a bell is rung in a vacuum container, will its sound be heard outside?
Answer:
Its sound will not be heard outside.

Observe and Discuss.

Observe the figure and answer the questions.

Question 1.
Which of these sounds is pleasant?
Answer:
The singing of the girl is a pleasant sound.

Question 2.
Which sound is a nuisance to people?
Answer:

1. Boy shouting/screaming.
2. Boy moving/ walking with a toy rattle.

Observe the figure and answer the following.

Question 1.
Make a list of all sounds implied in the picture.

Answer:

1. Chirping of bird outside the house on the tree.
2. Collision of two vehicles – honking of the vehicles.
3. Baby crying.
4. Father talking on the phone.
5. Brother playing in the house – jumping.
6. Sister playing the drum – hitting the drum.
7. Sound of TV.
8. Dog barking.
9. Mother talking to the neighbour.

Question 2.
How would this atmosphere affect a person who is not feeling well?
Answer:
This atmosphere is not convenient for a patient who is ill. He cannot take rest.

Question 3.
Would you be able to study in these conditions?
Answer:
No, students cannot study in this condition. They cannot concentrate on their study.

6th Std Science Questions And Answers:

• Work and Energy Class 6 Questions And Answers
• Simple Machines Class 6 Questions And Answers
• Sound Class 6 Questions And Answers
• Light and the Formation of Shadows Class 6 Questions And Answers
• Fun with Magnets Class 6 Questions And Answers
• The Universe Class 6 Questions And Answers

Balbharti Maharashtra State Board Class 7 Science Solutions Chapter 2 Plants: Structure and Function Notes, Textbook Exercise Important Questions and Answers.

Std 7 Science Chapter 2 Plants: Structure and Function Question Answer Maharashtra Board

Class 7 Science Chapter 2 Plants: Structure and Function Question Answer Maharashtra Board

1. Give examples of 3 plants that have:

Question a.
Spiny fruits
Answer:
Jack fruit, Pineapple, Lychee (litchi), Datura

Question b.
Spiny stem
Answer:
Cactus, Wild rose, Catclaw acacia, Silk, Cotton

Question c.
Red flowers
Answer:
Rose, Dahlia, Hibiscus, Tulips,

Question d.
Yellow flowers
Answer:
Marigold, Daffodil, Sunflower, Daisy

Question e.
Leaves which close at night
Answer:
Mimosa plant, Tallwood, Prayer plant, Gulmohar

Question f.
Single seeded fruits
Answer:
Mango, Lychee, Jamun

Question g.
Many seeded fruits
Answer:
Custard apple, Papaya, Watermelon.

2. Observe any one flower and its various parts and describe it in your own words.

Question a.
Answer:

A flower has following parts:
1. Pedicel: (a) Flower may have a long or a short stalk called pedicel, (b) One end of the pedicel is attached to the stem, (c) The other end of the pedicel is expanded and swollen. It is called the receptacle, (d) Petals and other parts of the flower are supported on the receptacle.
2. Calyx: In the bud condition, the petals are covered by leaf like parts called sepals which are green in colour. They form the calyx.
3. Corolla: This is made up of colourful parts called petals.
4. Androecium: (a) This is the male reproductive part of the flower, (b) It consists of stamens, (c) Each stamen is made up of anther and filament.
5. Gynoecium: (a) This is the female reproductive part of the flower, (b) This is made up of carpels, (c) A carpel consists of stigma, style and ovary.

3. What are the similarities and differences between?

Question a.
Jowar and Moong
Differences:

Jowar	Moong
i. It has fibrous root.	i. It has tap root.
ii. It is a monocotyledonous seed.	ii. It is a dicotyledonous seed.
iii. It is a rabi crop.	iii. It is a kharif crop

Similarities:
Jowar and Moong both are angiosperms.

Question b.
Onion and Coriander
Differences:

Onion	Coriander
i. It is a biennial plant.	i. It is an annual plant.
ii. It has monocoty­ledonous seed.	ii. It has dicotyledonous seeds.
iii. It has fibrous root.	iii. It has tap root but later on changes to fibrous root system.

Similarities:

1. Both are used in cooking.
2. Both are edible.
3. Both belongs to kingdom plantae.

Question c.
Leaves of banana and Leaves of mango
Answer:

Leaves of banana	Leaves of mango
i. It has parallel venation.	i. It has reticulate venation.
ii.  It is very large in size.	ii. It is small in size.
iii. It is a monocotyledonous plant.	iii. It is a dicotyledonous plant.

Question d.
Coconut tree and Jowar stalk plant
Answer:
Differences:

Coconut tree	Jowar stalk plant
i. It is tall and has a thick stem	i. It is small and has a thin stem.
ii. It has strong root system.	ii. It has weak root system.
iii. Each and every part of tree is useful.	iii. Only seeds are useful.

Similarities:

1. Both are from same kingdom plantae.
2. Both are autotrophic.
3. Both are monocotyledonous plants.

4. Explain the following images in your own words.

Question a.

Answer:

1. Diagram A is of maize seed. It is a monocotyledonous seed and does not divide into two equal parts. The plant has fibrous root system.
2. Diagram B is of bean seed. It is a dicotyledonous seed and it divides into two equal parts. The plant has tap root system.

5. Describe the functions of various parts of a plant.

Question a.
Describe the functions of various parts of a plant.
Answer:
The functions of various parts of a plant are as below.
1. Root: (a) Fixation: It anchors the plant body to the soil, so helps in fixation, (b) Absorption: It absorbs water and nutrients from the soil, so helps in absorption, (c) Conduction: The root translocates water and mineral salts into the stem. (d) Storage: A certain amount of food is stored in the root which is utilized as it grows.
(e) Preventing soil erosion: It helps to bind the soil particles and prevent them from being blown away by wind or water.
2. Stem: (a) It supports and holds leaves, flower and fruits, (b) The stem conducts the water and minerals from roots to leaves and fruits, (c) It stores the food.
3. Leaves: (a) It synthesizes food for the plant, (b) Stomata, the tiny openings in the leaf help in gaseous exchange and are responsible for the process of transpiration.
4. Flower: It helps in pollination.
5. Fruit: (a) It protects the seed, (b) It helps in seed dispersal.
6. Seed: A new plant develops from it.

6. Certain properties are mentioned below. Find a leaf corresponding to each property and describe those plants.

Question a.
Certain properties are mentioned below. Find a leaf corresponding to each property and describe those plants.
leaves with smooth surface, leaves with rough surface, fleshy leaf, spines on leaf.
Answer:

1. Leaves with smooth surface: e.g. Banana leaf. It is large in size. It is closely rolled up one over the other. Together they look like a trunk but they form only an apparent trunk. It has parallel venation.
2. Leaves with rough surface: e.g. Hibiscus leaf. It has reticulate venation. Leaf margin is toothed.
3. Fleshy leaf: e.g. Jade plant, water hyacinth. It has fleshy, glossy and smooth leaves. They are coloured jade green and having a slightly red tinge towards the edge of leaves when exposed to higher level of light.
4. Spines on leaf: e.g. Opuntia, Ci/cas, kevda. Opuntia is a desert plant. Leaf is thick, fleshy and having spines on it.

7. Find the plant parts.

Question a.

Answer:

ROOT, ROOT CAP, ROOT HAIR, BUD, PETALS, STEM, RADICLE, FLOWER, LEAF, VEIN, CALYX, NODE, OVUM.

Class 7 Science Chapter 2 Plants Structure And Function Question Answer Activity:

Sketch various types of leaves in Paintbrush on the computer and save the sketches in a folder of your own name.

Class 7 Science Chapter 2 Plants: Structure and Function Important Questions and Answers

Plants Structure And Function Exercise Fill in the blanks:

Plants Structure And Function Class 7 Questions And Answers Question 1.
The part that grows from inside the seed towards the soil is called the …………….. .
Answer:
radicle

Plants Structure And Function Class 7 Question 2.
The part that grows above the soil from the seed is called the …………….. .
Answer:
plumule

Plants Structure And Function Question And Answer Question 3.
The part of the plant growing below the soil from radicle for support is called …………….. .
Answer:
root

Plants Structure And Function Class 7 Exercise Question 4.
The …………….. protects the root-tip from injuries.
Answer:
root cap

Plants Structure And Function Exercise Question 5.
Roots bearing hair like processes near the root tips are called …………….. .
Answer:
root hairs

Class 7 Science Chapter 2 Plants Structure And Function Question Answer Question 6.
Thread-like or fibre like roots arising from the stem are called ……………. .
fibrous roots

Question 7.
The stem grows above the soil from the …………….. of the sprouting seed.
Answer:
plumule

Question 8.
Leaves come out at the …………….. .
Answer:
nodes

Question 9.
The part of the stem between two nodes is called …………….. .
Answer:
inter node

Question 10.
The tip or the apical end of the stem is called a …………….. .
Answer:
bud

Question 11.
The broad, spread out part of the leaf is called the …………….. or …………….. .
Answer:
leaf blade, lamina

Question 12.
The tip of the leaf is called the …………….. .
Answer:
leaf apex

Question 13.
Leaves of some plants have a stalk called a …………….. .
Answer:
petiole

Question 14.
The portion of the leaf attached to the stem is called the …………….. .
Answer:
leaf base

Question 15.
Small leaf like structures near the leaf base is called …………….. .
Answer:
stipides

Question 16.
Flowers may have a long or a short stalk called …………….. .
Answer:
pedicel

Question 17.
One end of the pedicel is attached to the …………….. .
Answer:
stem

Question 18.
…………….. is a male reproductive organ of the flower.
Answer:
Androecium

Question 19.
…………….. is a female reproductive organ of the
Answer:
gynoecium

Question 20.
Androecium consists of …………….. .
Answer:
stamens

Question 21.
Gynoecium consists of …………….. .
Answer:
carpels

Question 22.
Seeds which get divided into two equal parts are called …………….. seeds.
Answer:
dicotyledonous

Question 23.
Seeds which do not divide into two equal parts are …………….. called seeds.
Answer:
monocotyledonous

Question 24.
Petals and other parts of the flower are supported on the …………….. .
Answer:
receptacle

Question 25.
Sepals are …………….. in colour.
Answer:
green.

Match the columns:

Question  1.

Column ‘A’	Column ‘B’
1. Peepal	a. carpels
2. Maize	b. stamen
3. Androecium	c. parallel venation
4. Gynoecium	d. reticulate venation

Answer:

Column ‘A’	Column ‘B’
1. Peepal	d. reticulate venation
2. Maize	c. parallel venation
3. Androecium	b. stamen
4. Gynoecium	a. carpels

Question 2.

Column ‘A’	Column B’
1. Tap roots	a. stem
2. Fibrous roots	b. root
3. Radicle	c. monocotyledonous plants
4. Plumule	d. dicotyledonous plants

Answer:

Column ‘A’	Column B’
1. Tap roots	d. dicotyledonous plants
2. Fibrous roots	c. monocotyledonous plants
3. Radicle	b. root
4. Plumule	a. stem

Question 3.

Column A’	Column B’
1. Leaf-tip	a. petiole
2. Edge of leaf blade	b. leaf margin
3. Portion of leaf attached to stem	c. lamina
4. Stalk of leaf	d. leaf apex
	e. leaf base

Answer:

Column A’	Column B’
1. Leaf-tip	d. leaf apex
2. Edge of leaf blade	b. leaf margin
3. Portion of leaf attached to stem	e. leaf base
4. Stalk of leaf	a. petiole

Say whether True or False Correct and rewrite the false statements:

Question 1.
Stem grows from radicle.
Answer:
False. Stem grows from the Plumule

Question 2.
Leaf margins may be entire, dentate or lobed.
Answer:
True

Question 3.
The leaf blade of leaves in some plants is divided into many small parts called leaflets.
Answer:
True

Question 4.
Maize plant has reticulate venation.
Answer:
False. Maize plant has parallel venation

Question 5.
A carpel consists of stigma, style and ovary.
Answer:
True.

Question 6.
A stamen is made up of nodes and internodes.
Answer:
False. A stamen is made up of anther filament

Question 7.
The ovary develops into a fruit.
Answer:
True

Question 8.
Fertilized ovules form the seeds.
Answer:
True

Question 9.
A mango fruit contains many seeds.
Answer:
False. A mango fruit contains only one seed

Question 10.
A fruit like cashew have seed outside the fruit.
Answer:
True.

Question 11.
Leaves of some plants do not have a petiole.
Answer:
True

Question 12.
The peepal leaf has parallel venation.
Answer:
False. It has reticulate venation.

Find the odd one out:

Question 1.
Pea, Moong, maize, groundnut
Answer:
Maize – Its seed is monocotyledonous, while others have dicotyledonous seeds.

Question 2.
Cashew, apple, mango, chikoo
Answer:
Cashew – Its seed is outside the fruit, others have internal seeds.

Question 3.
Stigma, anther, style, ovary
Answer:
Anther – It is a part of androecium, while others are a part of gynoecium.

Question 4.
Petiole, vein, calyx, apex
Answer:
Calyx – It is a part of flower, whereas others are parts of leaf.

Question 5.
Aerial, stilt, runner, lobed
Answer:
Lobed – It is a type of leaf margin, while others are types of modified roots.

Answer the following in one or two sentences:

Question 1.
Which types of roots do the fenugreek, spinach and onion plants have?
Answer:

1. Fenugreek and spinach have tap roots with a few secondary roots whereas onion has fibrous root.
2. Fenugreek roots also have some nodules which contain nitrogen fixing bacteria.

Question 2.
What are called prop roots?
Answer:
Roots emerging from the trunk and branches of a banyan tree grow towards the soil. These roots are called prop roots.

Question 3.
What is called reticulate venation?
Answer:

1. A leaf is divided into two equal parts by a single mid-vein which lies along the midline of the leaf blade.
2. Secondary veins arise from the mid-vein. They are branched and form a network or reticulum. Such a type of venation is called reticulate venation.

Question 4.
What is called parallel venation?
Answer:
In a leaf all the veins are parallel, running from the leaf base to the leaf apex. Such a venation is called parallel venation.

Question 5.
What is pollination?
Answer:
After maturity, anthers burst and the pollen grains which are released fall on the stigma. This process is called pollination.

Question 6.
Why are the underground parts of plants like radish, carrot, beet and sweet potato thick, fleshy and swollen? Which parts of the plant are they?
Answer:
The underground parts of plants like radish, carrot, beet and sweet potato are thick, fleshy and swollen because they store food in the form of starch. These are the root part of the plant.

Distinguish between:

Question 1.
Tap roots and fibrous roots.
Answer:

Tap roots	Fibrous roots
1. Roots of some plants produce secondary roots that grow obliquely and spread far and wide in the soil. This type of root is called a tap root.	1. Thread like or fibre roots arising from the stem are called fibrous roots.
2. It is found in dicotyledonous plant.	2.  It is found in monocotyle-donous plant.

Question 2.
Dicotyledonous seeds and monocotyledonous seeds.
Answer:

Dicotyledonous seeds	Monocotyledonous seeds
1. Seeds which get divided into two equal parts are called dicotyledonous seeds.	1. Seeds which do not divide into two equal parts are called monocotyledonous seeds.
2. Dicotyledonous seeded plants have tap root system.	2. Monocotyledonous seeded plants have fibrous root system.

Draw neat and labelled diagram for the following:

Question 1.
Tap root
Answer:

Question 2.
Parts of a leaf.
Answer:

Question 3.
Parts of stem
Answer:

Do as directed:

Question 1.
Certain properties are mentioned below. Find a leaf corresponding to each property and describe those plants.
Answer:

1. Leaves with smooth surface: e.g. Banana leaf. It is large in size. It is closely rolled up one over the other. Together they look like a trunk but they form only an apparent trunk. It has parallel venation.
2. Leaves with rough surface: e.g. Hibiscus leaf. It has reticulate venation. Leaf margin is toothed.
3. Fleshy leaf: e.g. Jade plant, water hyacinth. It has fleshy, glossy and smooth leaves. They are coloured jade green and having a slightly red tinge towards the edge of leaves when exposed to higher level of light.
4. Spines on leaf: e.g. Opuntia, Cycas, kevda. Opuntia is a desert plant. Leaf is thick, fleshy and having spines on it.

Use your brainpower!

Answer the following questions:

Question 1.
What would have happened if plants like tamarind, banyan and mango had fibrous roots?
Answer:
If plants like banyan, mango, tamarind had fibrous roots they would get uprooted and fall even with a little strong wind as the roots would not be able to support and anchor the trees firmly.

Question 2.
What will happen if the root-tip is injured?
Answer:

1. Root cap helps the root to grow downward It protects the sensitive part of the root and eases the movement of the root through the soil.
2. Injury of the root tip causes the root to grow randomly and it also may lead to injury of the sensitive part of the root.

Question 3.
Which types of roots do the fenugreek, spinach and onion plants have?
Answer:

1. Fenugreek and spinach have tap roots with a few secondary roots whereas onion has fibrous root.
2. Fenugreek roots also have some nodules which contain nitrogen-fixing bacteria.

Question 4.
Of what use to a plant are the insects flitting about around its flowers?
Answer:

1. The insects try to suck the nectar from the flowers and in that process the pollen grains stick to their legs.
2. When they sit on another flower the pollen grain stick to the stigma and the pollination takes place. Thus, these insects help in the pollination.

Observe the figure and answer the questions given.

1.

Question a.
What is shown in the picture?
Answer:
The picture shows the arrangement of leaves on the stem.

Question b.
What arrangement is shown in (A), (B), and (C)?
Answer:
(A) Alternate (B) Opposite (C) Whorled

2.

Question a.
Lable parts 1 to 6.
Answer:

1. Gynoecium or carpel
2. Corolla
3. Androecium (Stamen)
4. Ovary
5. Corolla
6. Pedicel

Question b.
Name the female reproductive part.
Answer:
Gynoecium

Question c.
Name the colourful part of the flower.
Answer:
Corolla

Question d.
Which part develops into fruit?
Answer:
Ovary

Question e.
Which pa pollination?
Answer:
The transfer of pollen grains from the anther to the stigma of flower is called pollination.

7th Std Science Questions And Answers:

• The Living World: Adaptations and Classification Class 7 Questions And Answers
• Plants: Structure and Function Class 7 Questions And Answers
• Properties of Natural Resources Class 7 Questions And Answers
• Nutrition in Living Organisms Class 7 Questions And Answers
• Food Safety Class 7 Questions And Answers
• Measurement of Physical Quantities Class 7 Questions And Answers
• Motion, Force and Work Class 7 Questions And Answers
• Static Electricity Class 7 Questions And Answers
• Heat Class 7 Questions And Answers
• Disaster Management Class 7 Questions And Answers

Balbharti Maharashtra State Board Class 6 Science Solutions Chapter 7 Nutrition and Diet Notes, Textbook Exercise Important Questions and Answers.

Std 6 Science Chapter 7 Nutrition and Diet Question Answer Maharashtra Board

Class 6 Science Chapter 7 Nutrition and Diet Question Answer Maharashtra Board

1. Fill in the blanks:

Question a.
The process of intake of food and utilizing it for all life processes is called ……………. .
Answer:
nutrition

Question b.
All the substances in our food which are useful for various body processes are called ………… .
Answer:
nutrients

Question c.
Carbohydrates and …………. provide …………… to our body.
Answer:
fats, energy

Question d.
In a balanced diet, all the nutrients are present in the ……………. proportion.
Answer:
right

Question e.
In the food pyramid, cereals are given the maximum space because they fulfill our …………… requirement.
Answer:
energy

Question f.
Intake of more food than necessary causes ………….. .
Answer:
overnutrition

2. Spot the following in the table of vitamins and minerals.

Question a.
The nutrient present in citrous fruits.
Answer:
Vitamin C

Question b.
Vitamins/minerals present in milk.
Answer:
Vitamin A, Vitamin B, Vitamin D, calcium, phosphorus.

Question c.
Causes and symptoms of night blindness, scurvy, rickets, beriberi.
Answer:

Diseases	Causes	Symptoms
1. Night blindness	Deficiency of Vitamin A	Inability to see in dim light
2. Scurvy	Deficiency of Vitamin C	Bleeding of gums
3. Rickets	Deficiency of Vitamin D	Softening of bones
4. Beri-beri	Deficiency of Vitamin B1	Nerve disorder, muscle weakness

Question d.
Foods required to prevent the above diseases.
Answer:

Diseases	*Causes	‘Symptoms	Food for prevention
1. Night blindness	Deficiency of Vitamin A	Inability to see in dim light	Carrots, milk, dark green vegetables.
2. Scurvy	Deficiency of Vitamin C	Bleeding of gums	Amla, kiwi, oranges and citrus fruits.
3. Rickets	Deficiency of Vitamin D	Softening of bones	Exposure to sunlight, milk, fish, egg, butter.
4. Beri-beri	Deficiency of Vitamin B1	Nerve disorder, muscle weakness	Milk, fish, meat, cereals, nuts, pulses

Question e.
Causes of anaemia.
Answer:
Deficiency of Vitamin B₁₂, iron.

Question f.
Essential mineral for healthy bones and teeth.
Answer:
Calcium, phosphorus.

Question g.
Sensory organ affected due to the deficiency of Vitamin A.
Answer:
Eyes, skin.

3. Choose the correct alternative. 

Question a.
Pulses are a very good source of ……………. .
(1) carbohydrates
(2) proteins
(3) fats
(4) minerals
Answer:
(2) proteins

Question b.
…………. provide maximum energy to our body.
(1) Cereals
(2) Leafy Vegetables
(3) Water
(4) Amla
Answer:
(1) Cereals

Question c.
Goitre is caused by the deficiency of ……….. .
(1) iron
(2) calcium
(3) iodine
(4) potassium
Answer:
(3) iodine

Question d.
……….. is a type of junk food.
(1) Orange
(2) Milk
(3) Bhakri
(4) Chocolate
Answer:
(4) Chocolate

4. Use the food pyramid to select food items of your choice for three days.
Conditions:
1. The diet for all three days should be balanced.
2. There should be variety in the items chosen for the three days.
Answer:

Day 1:
Cereal like cornflakes and milk, apple, roti, sabzi and dal.

Day 2:
Bread and butter with milk, rice/ roti and chicken, curd, any one type of fruit, salad.

Day 3:
Poha, green vegetable and dal with rice or roti, raita, one fruit, vegetable sandwich.

Activity:

Question 1.
Obtain information on simple methods of spotting the adulteration in foodstuffs and try them out.

Class 6 Science Chapter 7 Nutrition and Diet Important Questions and Answers

Choose the correct alternative:

Question 1.
Vitamin ……………. and vitamin …………….. dissolve easily in water.
(a) A, B
(b) B, C
(c) B, D
(d) B, E
Answer:
(b) B, C

Question 2.
……………. carries oxygen to all parts of the body.
(a) Calcium
(b) Iron
(c) Iodine
(d) Sodium?
Answer:
(b) Iron

Question 3.
Deficiency of vitamin ……………. causes excessive bleeding after an injury.
(a) A
(b) B
(c) K
(d) D
Answer:
(c) K

Question 4.
In accordance with the food pyramid, the proportion of ……………. should be least in our diet.
(a) cereals
(b) fruits
(c) milk
(d) oil
Answer:
(d) oil

Question 5.
……………. is a rich source of vitamin C.
(a) Carrot
(b) Amla
(c) Meat
(d) Milk
Answer:
(b) Amla

Question 6.
Children of growing age need to get approximately ……………. to ……………. calories from the food they eat.
(a) 1500-2000
(b) 3150-4150
(c) 2000-2500
(d) All of them
Answer:
(c) 2000-2500

Fill in the blanks:

Question 1.
All food that we consume during the day is together called our ………. .
Answer:
diet

Question 2.
………….. convert milk into yogurt.
Answer:
Probiotics.

Match the columns:

Question 1.

Column ‘A’	Column ‘B’
1. Carbohydrates	a. resistance to diseases
2. Proteins	b. energy
3. Fibre	c. growth
4. Vitamins	d. excretion

Answer:

Column ‘A’	Column ‘B’
1. Carbohydrates	b. energy
2. Proteins	c. growth
3. Fibre	d. excretion
4. Vitamins	a. resistance to diseases

Question 2.

Column ‘A’	Column ‘B’
1. Iron	a. Goitre
2. Calcium and phosphorous	b. Anaemia
3. Iodine	c. Inefficiency of muscles
4. Sodium and potassium	d. Weak bones

Answer:

Column ‘A’	Column ‘B’
1. Iron	b. Anaemia
2. Calcium and phosphorous	d. Weak bones
3. Iodine	a. Goitre
4. Sodium and potassium	c. Inefficiency of muscles

Question 3.

Column ‘A’	Column ‘B’
1. Vitamin A	a. Scurvy
2. Vitamin C	b. Excessive bleeding
3. Vitamin D	c. Skin disorders
4. Vitamin E	d. Nightblindness
5. Vitamin K	e. Rickets

Answer:

Column ‘A’	Column ‘B’
1. Vitamin A	d. Nightblindness
2. Vitamin C	a. Scurvy
3. Vitamin D	e. Rickets
4. Vitamin E	c. Skin disorders
5. Vitamin K	b. Excessive bleeding

Pick out the odd one:

Question 1.
Chocolate, chapatti, banana, milk
Answer:
Chocolate

Question 2.
Rice, chapatti, carrot, dal.
Answer:
Carrot

Question 3.
Scurvy, Rickets, Beriberi, Goitre.
Answer:
Goitre

Question 4.
Vitamin A, Vitamin C, Vitamin D, Vitamin E
Answer:
Vitamin C

Answer the following:

Question 1.
Why do living things need food and water?
Answer:
Living things take food and water and use them for:

1. Obtaining energy
2. Growth of the body
3. Carrying out day to day functions of the body.
4. Fighting against diseases

Question 2.
Name the main nutrients in our food.
Answer:
There are six main nutrients in our food. They are:

1. Carbohydrates
2. Fats
3. Proteins
4. Fibres
5. Vitamins
6. minerals

Question 3.
How do we get energy from the food?
Answer:

1. We get energy in the form of heat from the food we eat.
2. Heat is measured in kilocalories (calories).
3. Hence, the energy in food items is also measured in kilocalories (calories).

Question 4.
Vitamin C rich food should be eaten raw. Why?
Answer:

1. Vitamin C is very sensitive to heat and light.
2. It is destroyed easily during cooking. Hence, Vitamin C rich food should be eaten raw.

Question 5.
What is balanced diet? Give its significance.
Answer:
A diet containing adequate quantities of all nutrients is called as balanced diet. Significance of a balanced diet are:

1. An increased capacity to work.
2. Good physical and mental health.
3. Increased capacity to fight/resist diseases.
4. Helps in proper growth of the body.

Question 6.
What is obesity? How to avoid obesity?
Answer:

• Obesity is the state of being overweight.
• Junk food eaten frequently causes obesity.
• Obesity is not good for health.

To avoid obesity:

1. Have a balanced diet.
2. Eat whole grains, fruits and vegetables with their skins.
3. Increase use of bicycles.
4. Play more outdoor games.
5. Do not eat if you are not hungry.
6. Do not watch T.V while eating.
7. Avoid precooked, packaged food.
8. Exercise regularly.

Write short notes.

Question 1.
Vitamins:
Answer:
1. Vitamins are vital substances required by our body in small quantities. They help to improve the body’s resistance to diseases. Their deficiency can lead to various diseases, e.g.: deficiency of Vitamin A causes night blindness and that of Vitamin D causes rickets. The sources of vitamins are vegetables, fruits, milk, fish, meat etc.
2. There are two kinds of vitamins – water soluble vitamins and water insoluble vitamins.
3. Vitamin B and Vitamin C are water soluble vitamins because they dissolve easily in water. They are thrown out of the body through the water in sweat and urine. Hence, a regular supply of these vitamins is essential. B₁₇B₂, B₃, B₆, B₉, and Bp are the types of vitamin B.
4. Vitamins A, D, E and K are insoluble in water but are fat soluble vitamins. They get stored in the body.

Question 2.
Probiotics:
Answer:

1. The useful microorganisms which convert milk into yoghurt are present in yoghurt and buttermilk are called probiotics.
2. Lakhs of such useful microorganisms are present in our intestine.
3. They are essential for our health.
4. Hence, to maintain them in our body we should include food rich in probiotics in our daily diet.

Question 3.
Junk food:
Answer:

1. Foods which gives us energy but do not supply the necessary nutrients are called junk food.
2. Foods like chocolate, pizzas, burgers, noodles, fried foods like pakodas are junk food.
3. These foods contain refined flour, sugar and oil in large proportion.
4. If we consume these foods frequently, our body experiences shortage of proteins, vitamins and minerals.
5. This may lead to malnutrition and obesity.

Question 4.
Adulteration of food:
Answer:
To earn more profits, cheaper substances of low quality called adulterants, are mixed with the foodstuffs. The mixing adulterants to foodstuffs is called adulteration of food. Adulterants may be poisonous or harmful and such food is impure and unfit for consumption.
Some of the adulterants added to foodstuffs are given below:

Give scientific reasons:

Question 1.
Deficiency of vitamin B and C are common in our body.
Answer:

1. Vitamin B and vitamin C are water soluble vitamins.
2. They are thrown out of the body through the water in sweat and urine.
3. Hence, a regular supply of these vitamins is essential.
4. If we don’t intake food rich in these vitamins, deficiency occurs.

Question 2.
Exposure to sunlight is essential.
Answer:

1. On exposure to sunlight our body synthesizes Vitamin D from substances in milk, fish, eggs and butter.
2. Its deficiency causes softening of bones (Rickets).
3. Vitamin D helps in absorbing calcium and phosphorous for healthy bones and teeth.
4. Hence, exposure to sunlight is essential.

Complete the tables given below:

1.

Nutrients	Source	Function
1. Carbohydrates	Rice, chapatti	Provide energy
2. Fats	Oil, butter	Provide energy
3. Proteins	Sprouts, meat, eggs	Growth, repairing wear and tear of the body.
4. Vitamins	Vegetables, fruits	Improve body’s resistance to diseases
5. Fibre	Sprouts, vegetable, fruits	Help in excretion

2.

Mineral	Source	Function
1. Iron	Spinach, raisins	Carrying oxygen to all parts of the body
2. Calcium, phosphorous	Milk, milk products, meat	Strengthen bones and teeth
3. Iodine	Raisins, fish, sea fish	Controls growth, speeds up chemical reactions in the body.
4. Sodium and potassium	Salt, leafy vegetables, fruits, pulses	Maintain the body’s water balance and functioning of the muscles and nervous system.

3.

Vitamins	Source	Function
1. A	Carrot, milk, vegetables	Protects eyes, helps to keep skin, bones and teeth healthy.
2. B1	Milk, fish, cereals	Helps in proper function of nerves and heart.
3. B9	Deep green vegetables, papaya, kiwi	Growth of the body
4. B12	Meat, milk products	Formation of red blood cells
5. C	Amla, citrus fruits, green leafy vegetables	Protects body tissues
6. D	On exposure to sunlight, Vitamin D is made in our body	Formation of collagen – a protein essential for gums, teeth, bones and skin
7. E	Green  leafy vegetables, vegetable oil	Metabolism, reproduction
8. F	Green  leafy vegetables, sprouted pulses, yellow of egg	Helps in clotting of blood

Using the food items given below, prepare a balanced diet pyramid.
[Chapatti, banana, carrot, butter, Nan, egg, bread, cheese, dal, spinach, milk]
Answer:

Can you recall?

Question 1.
Which are the various groups of foodstuff? Which main constituents of food do we get?
Answer :
The various groups of foodstuffs are:

1. Milk and milk products, meat, fish, eggs.
2. Cereals and pulses
3. Vegetables and fruits.
4. Fatty substances oil, butter and ghee.

There are six main nutrients in our food: carbohydrates, fats, proteins, fibres, vitamins and minerals.

Nutrients	Foodstuffs
1. Carbohydrates	Cereals and pulses
2. Protein	Milk product, meat, fish, eggs
3. Fats	Butter, oil, ghee
4. Fibres	fruits and vegetables

Question 2.
What trouble do we have to face if we do not get enough fibre from our daily diet?
Answer:
Fibres help in excretion of food, if we do not get enough fibre we will face indigestion and stomach-ache.

Question 3.
What care must be taken to make sure that fibre is not lost or removed from the food we get?
Answer:
We must not over-cook the foodstuff containing fibres. Fruits should be eaten raw.

6th Std Science Questions And Answers:

• Natural Resources – Air, Water and Land Class 6 Questions And Answers
• The Living World  Class 6 Questions And Answers
• Diversity in Living Things and their Classification Class 6 Questions And Answers
• Disaster Management Class 6 Questions And Answers
• Substances in the Surroundings – Their States and Properties Class 6 Questions And Answers
• Substances in Daily Use Class 6 Questions And Answers
• Nutrition and Diet Class 6 Questions And Answers
• Our Skeletal System and the Skin Class 6 Questions And Answers
• Motion and Types of Motion
• Force and Types of Force Class 6 Questions And Answers