Class 10

Balbharti Maharashtra State Board Class 10 Science Solutions Part 2 Chapter 3 Life Processes in Living Organisms Part – 2 Notes, Textbook Exercise Important Questions and Answers.

Maharashtra State Board Class 10 Science Solutions Part 2 Chapter 3 Life Processes in Living Organisms Part – 2

Question 1.
Complete the following chart.

Asexual reproduction	Sexual reproduction
1. Reproduction that occurs with the help of somatic cells is called asexual reproduction.	1. __________________________________________ ____________________________________________
2. __________________________________________ ____________________________________________	2. Male and female parent are necessary for sexual reproduction.
3. This reproduction occurs with the help of mitosis only.	3. __________________________________________ ____________________________________________
4. __________________________________________ ____________________________________________	4. New individual formed by this method is genetically different from parents.
5. Asexual reproduction occurs in different individuals by various methods like binary fission, multiple fission, budding, fragmentation, regeneration, vegetative propagation, spore production, etc.	5. __________________________________________ _____________________________________________ _____________________________________________ _____________________________________________

Answer:

Asexual reproduction	Sexual reproduction
1. Reproduction that occurs with the help of somatic cells is called asexual reproduction.	1. Reproduction that occurs due to fertilization of gametes is called sexual reproduction.
2. For asexual reproduction only one parent is necessary.	2. Male and female parents are necessary for sexual reproduction.
3. This reproduction occurs with the help of mitosis only.	3. This reproduction occurs with the help of both mitosis and meiosis.
4. New individual formed by this method is genetically identical with parents.	4. New individual formed by this method is genetically different from parents.
5. Asexual reproduction occurs in different individuals by various methods like binary fission, multiple fission, budding, fragmentation, regeneration, vegetative propagation, spore production, etc.	5. Sexual reproduction occurs in two steps: First formation of haploid gametes by meiosis and then fertilization of these haploid gametes to form diploid zygote. There are no subtypes in the sexual reproduction.

Question 2.
Fill in the blanks.
a. In humans, sperm production occurs in the organ …………
(a) prostate gland
(b) testis
(c) ovaries
(d) Cowper’s gland
Answer:
(b) testis

b. In humans, …………. chromosome is responsible for maleness.
(a) X
(b) Y
(c) Z
(d) O
Answer:
(b) Y

c. In male and female reproductive system of human, …………. gland is same.
Answer:
There is no similar gland in male and female reproductive system. There may be some homologies but there is no similarity.

d. Implantation of embryo occurs in …………
(a) ovaries
(b) fallopian duct
(c) uterus
(d) vagina
Answer:
(c) uterus

e. …………type of reproduction occurs without fusion of gametes.
(a) Asexual
(b) sexual
(c) Fertilization
(d) Gamete formation
Answer:
(a) Asexual

f. Body breaks up into several fragments and each fragment begins to live as a new individual.
This is ………. type of reproduction.
(a) regeneration
(b) fragmentation
(c) binary fission
(d) budding
Answer:
(b) fragmentation

g. Pollen grains are formed by division in locules of anthers.
(a) meiosis
(b) mitosis
(c) amitosis
(d) binary
Answer:
(a) meiosis

Question 3.
Complete the paragraph with the help of words given in the bracket:
(Luteinizing hormone, endometrium of uterus, follicle stimulating hormone, estrogen, progesterone, corpus luteum)
Growth of follicles present in the ovary occurs under the effect of ………….. This follicle secretes estrogen. Ovarian follicle along with oocyte grows/regenerates under the effect of estrogen. Under the effect of ………….., fully grown up follicle bursts, ovulation occurs and …………….. is formed from remaining part of follicle. It secretes ……………. and ………. Under the effect of these hormones, glands of ……….. are activated and it becomes ready for implantation.
Answer:
Growth of follicles present in the ovary occurs under the effect of follicle stimulating hormone. This follicle secretes estrogen. Ovarian follicle along with oocyte grows/regenerates under the effect of estrogen. Under the effect of Luteinizing hormone, fully grown up follicle bursts, ovulation occurs and corpus luteum is formed from remaining part of follicle. It secretes estrogen and progesterone. Under the effect of these hormones, glands of endometrium of uterus are activated and it becomes ready for implantation.

Question 4.
Answer the following questions short.
a. Explain with examples types of asexual reproduction in unicellular organism.
Answer:


There are different methods of asexual reproduction in different unicellular animals.
(1) Binary fission: The process in which the parent cell divides to form two similar daughter cells
is binary fission. It takes place either by mitosis or amitosis. When there are favourable conditions and abundant food supply then the organisms undergo binary fission. Prokaryotes, Protists and eukaryotic 5 cell-organelle like mitochondria and chloroplasts perform binary fission.

Based on axis of fission there are three subtypes of binary fission.
(a) Simple binary fission: The plane of division is not definite, it can be in any direction due to lack of specific shape as in Amoeba.
(b) Transverse binary fission: The plane of J division is transverse, as in Paramoecium.
(c) Longitudinal binary fission: The plane of division is in length-wise direction as in Euglena.

(2) Multiple fission:

During unfavourable conditions when there is lack of food, multiple fission is shown by amoeba. Amoeba forms protective covering and becomes encysted. Inside the cyst, amoeba undergoes repeated nuclear division. This is followed by cytoplasmic divisions. Many amoebulae are formed which remain dormant inside the cyst. When favourable conditions reappear, they come out by breaking the cyst.

(3) Budding in yeast:

Yeast is unicellular fungus that performs budding. The parent cell produces two daughter nuclei by mitotic division. This results in a small bulgingbud on the surface of parent cell. One daughter nucleus enters the bud. It then grows and upon becoming big it separates from the parent cell to have independent life as new yeast cell.

b. Explain the concept of IVF.
Answer:
(1) IVF means In Vitro Fertilization (IVF)
(2) This is the technique in the modern medical field where childless couples can be blessed by their own child.
(3) IVF technique is used for childless couples who are faced with problems such as less sperm count, obstacles in oviduct, etc.
(4) The IVF technique is done by removing the oocyte from the mother and artificially fertilizing by the sperms collected from father. This fertilization is done in a test-tube. Thus it is also called test tube baby. The embryo formed is implanted in uterus of real mother or a surrogate mother at appropriate time.

c. Which precautions will you follow to maintain the reproductive health?
Answer:
About reproductive health one should have scientific and authentic information. The cleanliness of body is very essential but keeping the mind clean is also important to maintain good reproductive health. One should be careful about sexual relationships. These things should not be experimented in young age. Mistakes committed like these can change the sexual health forever. The cleanliness and hygiene during menstruation, the cleanliness of genitals and other private parts are the aspects of personal hygiene. When living in a society, one should always be away from cross-infections of venereal type.

d. What is menstrual cycle? Describe it in brief.
Answer:

• Menstrual cycle is the events of cyclic changes that takes place with the interval of 28 to 30 days in mature woman.
• Hormones from pituitary, FSH (Follicle Stimulating Hormone) and LH (Luteinizing Hormone) and hormones from ovary, estrogen and progesterone control the menstrual cycle.
• Due to influence of FSH, the ovarian follicle grows along with the oocyte that is present in it.
• This growing follicle produces estrogen.
• Under the influence of estrogen, the uterine inner layer called endometrium grows or regenerates. In the meantime the development of follicle is completed.
• LH from pituitary stimulates the bursting of ovarian follicle and releases the mature oocyte out of the follicle and the ovarian wall. This process is called ovulation.
• The empty ovarian follicle after the ovulation becomes corpus luteum. Corpus luteum produces hormone progesterone.
• Under the influence of progesterone, the glands from uterine endometrium start secreting. The oocyte if fertilized is implanted over this endometrium.
• If oocyte is not fertilized, the corpus luteum becomes a degenerate body called corpus albicans. The corpus albicans cannot secrete estrogen and progesterone.
• Due to lack of these hormones, the endometrial layer of the uterus collapses. The tissue debris, along with unfertilized egg is given out through the vagina as menstrual flow. This results in bleeding for about 5 days.
• If woman is not pregnant, then this menstrual cycle keeps on repeating with regularity.

Question 5.
In case of sexual reproduction, newborn show similarities about characters. Explain this statement with suitable examples.
Answer:
(1) Sexual reproduction occurs due to two different gametes. One male gamete is from father while the other female gamete is from mother.
(2) Both the gametes are produced by meiosis.
(3) When the gametes unite it is called process of fertilization which produces diploid zygote.
(4) Due to the chromosomes of parents, their DNA pass to the next generation through such fertilization. Therefore, the characters of newborn show similarities with parents.

Question 6.
Sketch the labelled diagrams.
a. Human male reproductive system.
Answer:

b. Human female reproductive system.
Answer:

c. Flower with its reproductive organs.
Answer:

d. Menstrual cycle.
Answer:

Question 7.
Give the names.
a. Hormones related with male reproductive system.
Answer:
Follicle stimulating hormone and ICSH or Luteinizing hormone secreted by pituitary gland, testosterone secreted by testis.

b. Hormones secreted by ovary of female reproductive system.
Answer:
Estrogen and progesterone.

c. Types of twins.
Answer:
Monozygotic twins, Siamese twins and Dizygotic twins.

d. Any two sexual diseases.
Answer:
Gonorrhea and Syphilis.

e. Methods of family planning.
Answer:
Copper T, condoms, oral contraceptive pills.

Question 8.
Gender of child is determined by the male? partner of couple. Explain with reasons whether this statement is true or false.
(OR)
“A couple shall have a male child or female child totally depends upon husband”. Prove truthfulness of this statement with scientific reason.
Answer:

Sex determination in Human being
(1) The statement Gender of child is determined by the male partner of couple is true.
(2) It is clearly seen from the diagram that there are two types of sperms produced by males. One sperm has a X chromosome while the other has a Y chromosome, apart from autosomes. The mother on the other hand has all X bearing oocytes. Thus the sperm that fertilizes the oocyte decides the sex of the child.
(3) If X bearing sperm fertilizes the oocyte, daughter is born and when Y bearing sperm fertilizes the oocyte, son is born.
(4) Thus father or male partner is responsible for the determination of the sex.

Question 9.
Explain asexual reproduction in plants.
Answer:

• Vegetative propagation is the method of asexual reproduction in plants.
• It takes place with the help of vegetative parts like root, stem, leaf and bud.
• Potato, suran (Amorphophallus) and other tubes propagate with the help of ‘eyes’ which are buds. These eyes are present on the stem tubers.
• In case of plants like sugarcane and grasses, buds present on nodes perform vegetative propagation.
• Plants like Bryophyllum performs vegetative propagation with the help of buds present on leaf margin.

Question 10.
Modern techniques like surrogate mother, sperm bank and IVF technique will help the human beings. Justify this statement.
OR
Despite various diagnostic tests, a couple could not have a child. In this situation, which remedies will you suggest? (July 2019)
Answer:
(1) Some couples want a child but they are not able to bear one due to various problems either in mother or in father. In such cases modern techniques such as IVF, surrogacy and sperm bank are useful in conceiving a child.

(2) These methods are as follows:
(i) Surrogacy: In woman if there is problem regarding the implantation of embryo in uterus, then help of another women is taken. This women is called surrogate mother.

Oocyte from real mother is taken out and fertilized with sperms collected from her husband. These gametes are fertilized outside in a test-tube and then the fertilized zygote is implanted in the surrogate mother.

(ii) In Vitro Fertilization (IVF) is done when there are problems like less sperm count or obstacles in oviduct. In IVF, fertilization is done in the test-tube. The embryo formed is implanted in uterus of woman for further growth.

(iii) Sperm bank: If man has problems with the sperm production, then the sperms are collected from the sperm bank. Sperm bank is the place where the donor’s donate the sperms and such sperms are kept stored. The donor’s identity is kept secret and he should also be physically and medically fit person.

Question 11.
Explain sexual reproduction in plants.
(OR)
Explain double fertilization in plants.
Answer:

• Plants reproduce sexually with the help of flowers.
• Androecium and gynoecium are male and female parts of the flowers respectively.
• In the carpel, the ovule undergoes meiosis and forms embryo sac.
• A haploid egg cell and two haploid polar nuclei are present in each embryo sac.
• The pollen grains from the anther reach the stigma of flower by the process of pollination. They germinate here on the stigma.
• As a result of germination, long pollen tube and two male gametes are formed.
• The pollen tube travels through the style of flower and the male gametes present in the pollen tube are transferred till the embryo sac in ovary. Upon reaching there, tip of the pollen tube bursts releasing two male gametes in embryo sac.
• One male gamete unites with the egg cell and forms zygote. While other male gamete unites with two polar nuclei forming the endosperm.
• Because there are two nuclei participating in this process, therefore it is called double fertilization.
• After fertilization ovule develops into seed and ovary forms a fruit. When the seed again gets favourable conditions, it can produce a new plant.

Activities: (Do it your self)

Question 1.
Collect the official data about present and a decade old population of various Asian countries and plot a graph of that data. With the help of it, draw your conclusions about demographic changes.

Question 2.
With the help of your teacher, compose and present a road show to increase the awareness about prenatal gender detection and gender bias.

Can you recall? (Text Book Page No. 22)

Question 1.
Which are the important life processes in living organisms?
Answer:
The important life processes in living organisms are respiration, circulation, nutrition, excretion, sensation and response through nervous system.

Question 2.
Which life processes are essential for production of energy required by body?
Answer:
The oxidation of nutrients that are absorbed in body is done because of oxygen supplied to cells by respiratory and circulatory system. This helps in liberation of energy. Thus respiration, circulation and nutrition are the life processes that are essential for production of energy required by body.

Question 3.
Which are main types of cell division? What are the differences?
Answer:
The main types of cell division are mitosis and meiosis. In mitosis, the chromosome number remains the same. 2 daughter cells are obtained from one cell. In meiosis, the chromosome number is reduced to half. From one cell, four daughter cells are obtained.

Question 4.
What is the role of chromosomes in cell division?
Answer:
Due to chromosomes, the DNA from parental cells enter into daughter cells. The hereditary, characters are transmitted to next generation by cell division.

Can you recall? (Text Book Page No. 22)

Question 1.
What do we mean by maintenance of species?
Answer:
Maintenance of species means a species undertakes successful reproduction and produces individuals of its own kind. This keeps the species existing on the earth.

Question 2.
Whether the new organism is genetically exactly similar to earlier one that has produced it?
Answer:
No. The new organism produced from the old one is not genetically exactly similar to the parents. In meiotic cell division there is crossing over in the homologous chromosomes. This produces genetic recombination. Thus the new organism is different from the earlier one. However, if the reproduction is of asexual type, then the young one is exactly similar to the parents.

Question 3.
Who determines whether the two organisms of a species will be exactly similar or not?
Answer:
The type of reproduction, whether it is asexual or sexual, the type of crossing over, the extent of genetic recombination, etc. determine the similarity among the parent organisms and their, offspring. Based on this genetic recombination the two organisms of a species do not show exact similarity. However, in case of monozygotic twins there is exact similarity. In asexual reproduction to there is similarity.

Question 4.
What is the relationship between the cell division and formation of new organism of same species by earlier existing organism?
Answer:
In the process of reproduction, there is division of chromosomes. Due to cell division, the gametes are formed. The union of gametes produce new offspring. In sexual reproduction, all these processes take place due to cell division. In asexual reproduction too there is cell division. Growth of new organism also occurs due to cell division.

Let’s Think: (Text Book Page No. 26)

Question 1.
What would have been happened if the male and female gametes had been diploid?
Answer:
Diploid (2n) gametes if united, they will form 4n, i.e. tetraploid variety. Such zygote will show severe abnormality. The chromosome number will not be maintained.

Question 2.
What would have been happened if any of the cells in nature had not been divided by meiosis?
Answer:
If meiosis does not happen the gametes produced will be diploid. This will create abnormality.

Can you recall? (Text Book Page No. 28)

Question 1.
Which different hormones control the functions of human reproductive system through chemical coordination?
Answer:
Pituitary gland secretes FSH and LH. LH is known as ICSH in males, as its function in the male body is different. From the gonads of male and female, hormones are secreted which are essential for male and female reproductive functions respectively. These hormones are testosterone secreted from testis in males and estrogen and progesterone secreted from the ovaries in females. Testosterone is essential for masculinity as well as for sperm production while female hormones are essential for changes in the female body leading to motherhood.

Question 2.
Which hormones are responsible for changes in human body occurring during onset of sexual maturity?
Answer:
Testosterone in male body and estrogen in female body are responsible for maturity onset changes in human body.

Question 3.
Why has the Government of India enacted the law to fix the minimum age of marriage as 18 in girls and 21 in boys?
Answer:
The full growth of female body is not completed till the age of 18. Till 18 years of age the physical and emotional maturity is not attained. Therefore, she is not suitable for marriage, sexual relationship and pregnancy. Similarly, boy attains complete growth only the age of 21. Therefore, to keep individuals and their progeny safe and healthy the Government of India enacted the law to fix the minimum age of marriage as 18 in girls and 21 in boys.

Can you recall? (Text Book Page No. 31)

Question 1.
Which hormone is released from pituitary of mother once the foetal development is completed?
Answer:
The hormone oxytocin is released from the posterior pituitary of mother once the foetal development is completed.

Question 2.
Under the effect of that hormone, which organ of the female reproductive system starts to contract and thereby birth process (parturition) is facilitated?
Answer:
Due to oxytocin, uterus contracts involuntarily and the baby is expelled out. Thus initiation of birth process is possible due to contractions of uterus.

Use your brain power. (Text Book Page No. 24)

Question 1.
Does the parent cell exist after asexual reproduction-fission?
Answer:
In fission, the parent cell divides into two. This nucleus and cytoplasm, both are divided. Thus, parent cell does not exist any longer, it is converted into new cells.

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

Question 1.
Pranav and Pritee are twins in your class. They belong to ……….. twins type.
(a) monozygotic
(b) dizyotic
(c) siamese
(d) none of the above
Answer:
(b) dizyotic

Question 2.
Longitudinal binary fission is seen in …………..
(a) Paramoecium
(b) Euglena
(c) Amoeba
(d) Spirogyra
Answer:
(b) Euglena

Question 3.
Yeast cell performs asexual reproduction by ……………..
(a) fragmentation
(b) budding
(c) binary fission
(d) regeneration
Answer:
(b) budding

Question 4.
Carrot and raddish undergoes …………. with the help of their roots.
(a) vegetative propagation
(b) fragmentation
(c) budding
(d) regeneration
Answer:
(a) vegetative propagation

Question 5.
Androecium and gynoecium are ……….. whorl of the flower.
(a) accessory
(b) essential
(c) external
(d) internal
Answer:
(b) essential

Question 6.
Flowers without stalk are called ……….. flowers.
(a) stalkless
(b) sessile
(c) incomplete
(d) complete
Answer:
(b) sessile

Question 7.
………….. on the inner surface of fallopian ducts (oviducts) push the egg towards uterus.
(a) Cilia
(b) Tentacles
(c) Flagella
(d) Fibres
Answer:
(a) Cilia

Question 8.
Pregnant mother supplies nourishment to her foetus through …………..
(a) breasts
(b) uterus
(c) placenta
(d) ovaries
Answer:
(c) placenta

Question 9.
The length of a sperm is about …………. micrometers.
(a) 400
(b) 5
(c) 60
(d) 600 (July ’19)
Answer:
(c) 60

Question 10.
Vegetative propagation is performed with the help of ……….. in sweet potato.
(a) root
(b) stem
(c) leaf
(d) flower
Answer:
(a) root

Question 11.
Which of the following is not a unisexual flower?
(a) Coconut
(b) Papaya
(c) Gulmohar
(d) Maize
Answer:
(c) Gulmohar

Write whether the following statements are true or false, with the suitable reason:

Question 1.
Absence of genetic recombination is an advantage whereas fast process is drawback of asexual reproductive method.
Answer:
False. (Absence of genetic recombination is a drawback whereas fast process is advantage of asexual reproductive method.)

Question 2.
Prokaryotes show fission which occurs either by mitosis or amitosis.
Answer:
True. (Prokaryotes show fission by both the methods, i.e. mitosis and amitosis.)

Question 3.
During favourable conditions multiple fission is performed by amoeba.
Answer:
False. (During unfavourable conditions multiple fission is performed by amoeba.)

Question 4.
Any encysted Amoeba or any other protist is called ‘Cyst’.
Answer:
True. (Cyst is the tough capsule like structure which keeps the protists dormant inside it. This helps the organisms to tide over unfavourable conditions.)

Question 5.
If the body of Sycon breaks up accidentally into only large and few fragments, then only each fragment develops into new Sycon.
Answer:
False. (If the body of Sycon breaks up accidentally into many fragments, each fragment develops into new Sycon. Because the capacity to regenerate is very strong in poriferan Sycon, even a small piece of parent Sycon can give rise to entire new individual.)

Question 6.
Pollen tube reaches the zygote via style.
Answer:
False. (Pollen tube reaches the embryo sac via style. Later, double fertilization takes place and the zygote and endosperm are formed.)

Question 7.
There is glucose sugar in the semen.
Answer:
False. (There is fructose sugar in the semen. Glucose is not present in semen.)

Question 8.
Out of 2 – 4 million ova, approximately only 400 oocytes are released up to the age of menopause.
Answer:
True. (During the reproductive span of the woman, from menarche to menopause only one oocyte per one month is released in the span of 30 to 35 years.)

Question 9.
If the oocyte is fertilized, secretion of estrogen and progesterone stops completely.
Answer:
False. (If the oocyte is not fertilized, there is no need of corpus luteum which secretes progesterone. In absence of conception, the progesterone is not needed, thus corpus luteum degenerates and forms corpus albicans.)

Question 10.
During menstruation there is need of rest along with special personal hygiene.
Answer:
True. (During phase of menstruation there is pain and bleeding in woman. Her body is also susceptible for infections. There is weakness and hence she needs rest along with special personal hygiene.)

Find the odd one out:

Question 1.
Circulation, Excretion, Sensation, Reproduction.
Answer:
Reproduction. (All others are processes necessary for survival of the individual.)

Question 2.
Budding in hydra, Regeneration, Binary fission, Fragmentation
Answer:
Binary fission. (All others are processes of asexual reproduction in multicellular organisms.)

Question 3.
Carrot, Radish, Potato, Sweet potato.
Answer:
Potato. (All others are edible roots.)

Question 4.
Vas eferens, vas deferens, prostate gland, epididymis.
Answer:
Prostate gland. (All others are duct systems in male reproductive system.)

Question 5.
Prostate gland, Bartholin’s gland, Cowper’s gland, Epididymis.
Answer:
Bartholin’s glands. (All others are parts of male reproductive system.)

Question 6.
Stigma, style, pollen, ovary.
Answer:
Pollen. (All others are parts of gynoecium.)

Identify the correlation between the first two words and suggest the suitable words in the fourth place:

Question 1.
Amoeba : Fission : : Hydra : ………….
Answer:
Amoeba : Fission : : Hydra : Budding

Question 2.
Transverse binary fission : Paramoecium : : Longitudinal binary fission : ………… (July ‘19)
Answer:
Transverse binary fission : Paramoecium : : Longitudinal binary fission : Euglena

Question 3.
Calyx : Sepals : : Corolla : ………….
Answer:
Calyx : Sepals : : Corolla : Petals

Question 4.
Accessory whorls : Calyx and corolla : : Essential whorls : ………..
Answer:
Accessory whorls : Calyx and corolla : : Essential whorls : Androecium and gynoeciuin

Question 5.
Bisexual flower : Hibiscus : : Unisexual flower : ………….
Answer:
Bisexual flower : Hibiscus : : Unisexual flower : Papaya

Question 6.
FSH : Development of qocyte : : LH : ………….
Answer:
FSH : Development of qocyte : : LH : Ovulation

Define the following/Give meanings of the following:

Question 1.
Budding in yeast.
Answer:
Budding in yeast: Budding is the asexual reproductive process in which a! small bulge or bud appears on the surface of parent cell as seen in unicellular yeast.

Question 2.
Budding in hydra.
Answer:
Budding in hydra: Budding in hydra is asexual reproductive process in which an outgrowth is formed by repeated divisions of regenerative cells of body wall called bud.

Question 3.
Regeneration.
Answer:
Regeneration: Regeneration is the asexual reproduction in Planaria in which the body is broken up into two parts and resulting each part regenerates remaining part of the body.

Question 4.
Fragmentation.
Answer:
Fragmentation: Fragmentation is the asexual type of reproduction in which the body of parent organism breaks up into many fragments. Each fragment can start living independently.

Question 5.
Vegetative propagation.
Answer:
Vegetative propagation: Vegetative propagation is a type of asexual reproduction in plants that takes place with the help of vegetative parts like root, stem, leaf and bud.

Question 6.
Fertilization.
Answer:
Fertilization: The process by which two haploid gametes unite to form a diploid zygote is called fertilization.

Question 7.
Pedicel.
Answer:
Pedicel: The stalk of the flower which is for the support is called pedicel.

Question 8.
Pollination.
Answer:
Pollination: Transfer of pollen grains from anther to the stigma is called pollination.

Question 9.
Self-Pollination.
Answer:
Self-Pollination: Pollination involving only one flower or two flowers borne on same plant is called self-pollination.

Question 10.
Cross-Pollination.
Answer:
Cross-Pollination: Pollination involving two flowers borne on two plants of same species is cross-pollination.

Question 11.
Endosperm.
Answer:
Endosperm: Endosperm is the nourishing substance formed by the union of second male gamete with two polar nuclei at the time of fertilization in plants.

Question 12.
Embryo sac.
Answer:
Embryo sac: There are many ovules in the ovary, the structure formed in each of the ovule by meiosis is called embryo sac.

Question 13.
Menopause.
Answer:
Menopause: Stoppage of functioning of female reproductive system due to lack of synthesis of hormones due to advancing age is called menopause.

Question 14.
Placenta.
Answer:
Placenta: An organ developed in the uterus of the pregnant mother, through which the embryo is given nourishment is called placenta.

Question 15.
Menstrual cycle.
Answer:
Menstrual cycle: The repetitive changes at the interval of every 28-30 days in female reproductive system that take place after puberty, form menstrual cycle.

Question 16.
Corpus luteum.
Answer:
Corpus luteum: Corpus luteum is the secondary structure that is formed from empty ovarian follicle after ovulation. This corpus luteum produces progesterone and thereby maintains pregnancy.

Question 17.
Corpus albicans.
Answer:
Corpus albicans: Corpus albicans is the degenerate body which is formed from corpus luteum, if the ovum is not fertilized.

Question 18.
Ovulation.
Answer:
Ovulation: Bursting of mature ovarian follicle under the influence of hormones to release the oocyte is called ovulation.

Question 19.
IVF.
Answer:
IVF: In Vitro Fertilization is the technique in which fertilization is brought about outside the female body but in the test-tube and the embryo is implanted in uterus of woman.

Question 20.
Sperm bank.
Answer:
Sperm bank: Sperm bank is the place where semen donated by the desired men is collected after their thorough physical and medical check-up and stored at sub-zero temperatures in sterile conditions.

Name the following/Give the names:

Question 1.
Different glands associated with male reproductive system.
Answer:
Seminal vesicles, Prostate gland, Cowper’s or bulbourethral glands.

Question 2.
Agents of pollination.
Answer:
Biotic: Insects, birds, few animals.
Abiotic: Water and wind.

Question 3.
Components of semen.
Answer:
Secretion of prostate gland seminal vesicles and Cowper’s glands along with sperms.

Question 4.
Two accessory whorls in flower.
Answer:
Calyx and corolla.

Question 5.
Two essential whorls in flower.
Answer:
Androecium and gynoecium.

Question 6.
The modern techniques in reproduction.
Answer:
In Vitro Fertilization, Surrogate mother, Sperm bank.

Question 7.
Symptoms of gonorrhea.
Answer:
Painful and burning sensation during urination, oozing of pus through penis and vagina, inflammation of urinary tract, anus, throat, eyes, etc.

Question 8.
Symptoms of syphilis.
Answer:
Occurrence of chancre (patches) on various parts of body including genitals, rash, fever, inflammation of joints, alopecia, etc.

Write the functions of the following organs:

Question 1.
Sporangium.
Answer:
Storing the spores and releasing them by bursting.

Question 2.
Calyx.
Answer:
Protection of inner whorls of the flower.

Question 3.
Corolla.
Answer:
Attracting insects for pollination. Protecting inner whorls.

Question 4.
Androecium.
Answer:
Production of pollen grains, the male gametes of flower.

Question 5.
Gynoecium.
Answer:
Production of female gametes of flower. Participating in production of fruits.

Question 6.
Endosperm.
Answer:
Nourishment of the growing embryo.

Question 7.
Testis.
Answer:
Production of sperms and male hormone-testosterone.

Question 8.
Scrotum.
Answer:
Protection and temperature control of testis.

Question 9.
Seminal vesicles.
Answer:
Secretion of seminal fluid which forms major portion of semen. Nourishment of sperms.

Question 10.
Penis.
Answer:
Transferring of sperms to vagina at the time of intercourse. Release of urine at the time of urination.

Question 11.
Ovary.
Answer:
Production of oocytes and female hormones – estrogen and progesterone.

Question 12.
Uterus.
Answer:
Growth and development of foetus during pregnancy. Helping in parturition (childbirth) by contractions.

Question 13.
Fallopian tubes/ducts.
Answer:
Transporting the released oocyte after ovulation to the uterus. Providing space for fertilization of oocyte by sperm. Conception is possible only when sperm and oocyte meet in the fallopian tube.

Question 14.
Vagina.
Answer:
Passage for copulation/intercourse. Birth canal. Passage for menstrual flow.

Question 15.
Placenta.
Answer:
Supplying nourishment to the growing foetus.

Distinguish between:

Question 1.
Binary fission and Multiple fission.
Answer:
Binary fission:

1. Two new individuals are formed from one old individual at one time.
2. The division of nucleus and cytoplasm takes place initially.
3. The axis of division can be transverse, longitudinal or any one axis as it is in simple binary fission.
4. Formation of protective cyst does not take place.
5. Binary fission can be done during favourable period.

Multiple fission:

1. Many new individuals are formed from one old individual at one time.
2. Only nucleus divides initially followed by division of cytoplasm.
3. There is no exact axis for the fission.
4. Protective covering is formed around dividing amoebulae which is called cyst.
5. Multiple fission takes place only at the time of unfavourable period.

Question 2.
Human male and Human female reproduction system.
Answer:
Human male reproductive system:

1. Testis are essential organs which are located outside the abdomen in the scrotal sacs.
2. There is common urethra through which urine and semen, are passed out.
3. Reproductive system of male continues to work even in old age.
4. Sperms or male gametes are produced by meiosis in the testis.
5. Sperms are produced in millions at one time.
6. Three accessory glands are associated with the male reproductive system.
7. Testis secrete testosterone which is essential male hormone.

Human female reproductive system:

1. Ovaries are essential organs which are located along with all other organs inside the lower abdomen.
2. Urethra and vagina are two separate openings that open to outside.
3. Reproductive system works only till menopause.
4. Oocytes or ova are produced by meiosis in the ovaries.
5. Only single oocyte is produced per month.
6. Only one gland is associated with female reproductive system.
7. Ovaries produce estrogen and progesterone which are essential female hormones.

Question 3.
Monozygotic twins and Dizygotic twins.
Answer:
Monozygotic twins:

1. Two children developing from only one zygote are called monozygotic twins.
2. Monozygotic twins develop from same oocyte.
3. Gender of both the twins is same.
4. The monozygotic twins are genetically exactly alike.

Dizygotic twins:

1. Two children developing from two different zygotes are called dizygotic twins.
2. Dizygotic twins develop from two different oocytes.
3. Gender of both the twins can be same or can be different.
4. The dizygotic twins are genetically not exactly alike.

Give scientific reasons:

Question 1.
Individual developed by sexual reproduction always carry recombined genes of both the parents.
Answer:

• In sexual reproduction, the haploid male and female gametes are united to form diploid zygote.
• The zygote thus carries chromosomes of both parents which are transferred via male and female gametes.
• While producing gametes, there is meiosis in which genetic recombination takes place.
• Therefore, the individual developed by sexual reproduction always carry recombined genes of both the parents.

Question 2.
Flower is the structural unit of sexual reproduction in plant.
Answer:

• Flower produces male and female gametes.
• For this purpose there are essential whorls of androecium and gynoecium.
• The double fertilization also takes place in flower.
• Therefore, flower is called the structural unit of sexual reproduction in plants.

Question 3.
Fertilization in plants is called double fertilization.
Answer:

• After pollination the pollen grains drop on the sticky stigma of the flower.
• They germinate here producing two male gametes and a long pollen tube.
• The male gametes travel through the pollen tube till they reach the embryo sac.
• Here the male gametes are released by bursting the pollen tube. One male gamete unites with the egg cell to form zygote while the second male gamete unites with two polar nuclei forming endosperm.
• In this way because two nuclei participate in the fertilization process, therefore it is called double fertilization.

Question 4.
By the age of 45 – 50 women gets menopause.
Answer:

• By the age of 45-50, the secretion of hormones which control the functioning of the reproductive system is reduced gradually and then it stops.
• This causes end of menstrual cycle. This results into menopause.

Question 5.
Older mothers have greater chance of conceiving abnormal children.
Answer:

• In older women the menopausal age approaches.
• The oocytes, released from ovaries during this phase are not normal.
• Their meiotic cell division is abnormal and thus oocyte becomes abnormal too.
• If such abnormal oocytes are fertilized, the baby is born with many genetic problems, e.g. Down’s syndrome or Turner’s syndrome.

Question 6.
Indians should follow family planning for controlling the population.
Answer:

• There is severe population explosion in India. It has almost reached to 121 crores.
• This results into unemployment, decreasing per capita income and increasing loan, stress on natural resources, etc.
• Only by controlling population, the quality of life can be restored.
• Therefore, Indians should follow family planning for controlling the population.

Answer the following questions in short:

Question 1.
How does reproduction take place in fungus Mucor?
Answer:

• Mucor reproduces asexually by spore formation.
• It has filamentous body that possess sporangia.
• When the spores are formed, the sporangia burst. The spores are released which settle down at suitable Places.
• They germinate in moist and warm place forming a new fungal colony.

Question 2.
What is the type of asexual reproduction shown in the diagram below? (Board’s Model Activity Sheet)
Answer:

Type of asexual reproduction shown in the diagram above is fragmentation in Spirogyra.

Question 3.
Describe the structure of a flower.

Answer:
(1) The structural unit of sexual reproduction in plants is flower. There are total four floral whorls. Of these, two are accessory floral whorls while two are essential floral whorls.
(2) Calyx and corolla are accessory whorls. They are protective in nature.
(3) Members of calyx are known as sepals. They are usually green in colour. They protect the inner whorls.
(4) The members of corolla are called petals. They can be of different colours.
(5) Androecium and gynoecium are essential whorls as they participate in sexual reproduction.
(6) The male whorl androecium is made up of stamens. Each stamen has a filament with anther located at the upper end. In the anther there are four locules. Inside the locules the meiosis takes place forming pollen grains. During suitable time, the pollen grains are released from anther lobes.
(7) Gynoecium is made up of carpels, either in separate form or are united. Each carpel is formed of ovary at the basal end hollow ‘style’ and the stigma at the tip of style. There are one or many ovules inside the ovary.
(8) In bisexual flowers both androecium and gynoecium are located in the same flower, e.g. Hibiscus.
(9) In unisexual flowers, androecium is present in male flowers and gynoecium is present in the female flowers, e.g. Papaya.

Question 4.
Describe the human male reproductive system.
Answer:

In human male reproductive system, the reproductive organs are as follows:

• Testes, different types of duct systems and glands.
• Testes are in pair. Each testis lies in the scrotum which lies outside to abdominal cavity.
• Testes -consist of numerous seminiferous tubules. The germinal epithelium of seminiferous tubules form sperms by undergoing meiosis.
• These sperm cells are immature.
• They are pushed gradually through various duct systems till the penis.
• This path is as follows:
  Rete testis → vas efferentia → epididymis → vasa deferentia → Ejaculatory duct → urethra
• As the sperms are travelling, they gradually become mature. They are made capable to perform process of fertilization.
• Seminal vesicles (in pairs), Single prostate gland and a pair of Cowper’s glands secrete their secretions. These secretions and the sperms together form semen.
• This semen is deposited in the vagina with help of penis.

Question 5.
Describe the human female reproductive system.
Answer:

• All the organs of the human female reproductive system are located inside the lower abdomen.
• There are pair of ovaries, pair of fallopian ducts and a single median uterus.
• The uterus opens out by vagina. In vaginal walls there are Bartholin’s glands.
• The urethra in female body is separate and not a common passage as in male body.
• The free end of fallopian duct is funnel-like having an opening in the centre. The oocyte released from the ovary due to ovulation is picked up by this funnel.
• The other end of fallopian duct opens into uterus. There are cilia on inner surface of oviduct. With the help of the cilia the oocyte is pushed to the uterus through the fallopian duct.
• The fertilization of oocyte can take place only in the middle’part of the fallopian duct.
• The lower end of uterus opens into vagina. The contractions of uterus help in the process of parturition.
• Vagina is the birth canal as well as copulatory passage. It is also a passage for menstrual flow.

Question 6.
What problems cause infertility in couple?
Answer:

• In woman if there are problems like irregularity in menstrual cycle, difficulties in oocyte production or implantation in uterus, obstacles in the oviduct, etc.
• In man if there are no sperms in the semen, slow movement of sperms, or anomalies in the sperms then he becomes sterile.
• But now with the help of advanced medical techniques these problems can be overcome and a childless couple can be parents.

Question 7.
Answer the following questions: (July 2019)
(a) In our country, there seems to be lack of awareness regarding reproductive health. Why?
(b) Write the symptoms of disease gonorrhea.
(c) What precautions will you take to maintain reproductive health?
Answer:
(a) There is lack of awareness about reproductive health among majority of people of our country. This is due to social customs, traditions, illiteracy, social taboo and shyness.

(b) Symptoms of gonorrhea are as follows:

1. Painful burning during urination.
2. Oozing of pus through penis or vagina.
3. Inflammation of urinary tract, anus, throat, eyes, etc.

(c) Precautions to maintain reproductive health are cleanliness and personal hygiene. Guarding against any sexual infections.

Question 8.
If a piece of bread is kept in a container in moist place for 2-3 days, (1) What will you see? (2) Write scientific name and a character of the organism you may observe.
Answer:
(1) If a piece of bread is kept in moist container we can see growth of fungus on it.
(2) Fungi belonging to species Mucor is seen. It has filamentous body and sporangia. Sporangia burst open to spread spores. It has saprophytic mode of nutrition as it devoid of chlorophyll.

Write short notes on:

Question 1.
Multiple fission.
Answer:

During unfavourable conditions when there is lack of food. multiple fission is shown by amoeba. Amoeba forms protective covering and becomes encysted. Inside the cyst, amoeba undergoes repeated nuclear division. This is followed by cytoplasmic divisions. Many amoebulae are formed which remain dormant inside the cyst. When favourable conditions reappear, they come out by breaking the cyst.

Question 2.
Regeneration.
Answer:

In developed animals like wall lizard the process of regeneration is used to restore the lost parts like tail or limbs. As the reproductive system is one of the fullfledged system in the body, the process of regeneration cannot be called type of reproduction.

But some primitive organisms such as Plarfaria use this method for procreation. Planaria breaks up its body into two parts. Each part has the ability to develop the lost part by process of regeneration. This forms two new Planaria.

Question 3.
Seed germination.
Answer:

Seed germination is the process in which the seed develops into a new plantlet. In the plants, after fertilization the ovule develops into seed and ovary turns into fruit. Seeds fallen on the ground due to bursting of the fruits start germinating. Only under favourable conditions in the soil, this germination takes place. The zygote present inside the seed uses food stored in endosperm of seed and hence develops further to produce a new plantlet.

Question 4.
Budding in hydra.
Answer:

In multicellular organisms asexual reproduction by budding is shown by hydra. In fully grown Hydra, at specific part of its body there is development of bud.

This development is only during favourable period. The bud is an outgrowth developed due to repeated divisions of regenerative cells of body wall. It grows up gradually to form a small hydra. Parent hydra’s dermal layers and digestive cavity are in continuity with those of the budding hydra. It receives all the nutrition from parent hydra.When the budding hydra grows sufficiently, it detaches from parent hydra. Then it leads an independent life.

Question 5.
Fragmantation.
Answer:

Fragmentation is one of the type of asexual reproduction in multicellular organisms. During fragmentation, the body of parent organism breaks up into many fragments. All the resulting fragments start to develop as an independent new organism. In alga Spirogyra, and sponge like Sycon asexual reproduction takes place by fragmentation. Spirogyra grow up very fast and break up into many small fragments when there are favourable conditions. Each newly formed fragment lives independently as a new Spirogyra. Similarly the body of Sycon if accidentally broken into many fragments, develops into new Sycon from each old fragment.

Question 6.
Monozygotic twins.
Answer:
The twins developed from a single embryo are called monozygotic twins. If within 8 days of zygote formation i.e. in early embryonic development cells of that embryo divide into two groups. Each one develop as two separate embryos forming two monozygotic twins. Monozygotic twins are genetically exactly similar to each other. The gender of the twins is also same.

The Siamese twins develop from monozygotic twins, if the embryonic cells are divided into two groups 8 days after the zygote formation. These are conjoined twins where some parts of body are joined to each other. Also some organs are common in Siamese twins.

Read the paragraph and answer the questions given below:

Reproduction is the process by which the living species continues its existence. Lower organisms carry out asexual reproduction while higher plants and animals always show sexual reproduction. Plants reproduce asexually by methods such as fragmentation, vegetative propagation, budding, spore formation. For sexual reproduction they form gametes. In animal kingdom, budding, fission of different types and parthenogenesis are some of the methods that do not require both the sexes. Though regeneration also forms new individual, it is not considered to be a reproductive process because, basically it is a repair process. The ability to regenerate is lost in higher phyla. In human beings | it is restricted only to wound healing. Sexual reproduction is also undergoing lots of experimentation such as cloning which may make females capable of producing their own baby without intervention of any male.

Questions and Answers:

Question 1.
How do living species continue their existence?
Answer:
Through the process of reproduction, living species continue their existence.

Question 2.
Which are asexual methods of reproduction in kingdom Animalia?
Answer:
Fission, budding and parthenogenesis are the asexual methods of reproduction in Kingdom Animalia.

Question 3.
Why is regeneration not true method of reproduction?
Answer:
Regeneration is the repair process than a reproductive process. It is not done with the intention of producing offspring, but is for healing or repairing the lost part.

Question 4.
What are methods of reproduction in plants?
Answer:
Plants reproduce by asexual as well as sexual methods. Asexual reproduction is by fragmentation, vegetative propagation, budding, spore formation, while by formation of gametes, sexual reproduction is done.

Question 5.
What is the modern method of reproduction aimed at in higher organisms?
Answer:
Cloning is the modern method of reproduction by which production of young one can be aimed at.

Diagram-based Questions:

Question 1.
Observe the figure 3.18 and answer the questions below: (Board’s Model Activity Sheet)

(a) What does the figure 3.18 indicate?
Answer:
The figure indicates the menstrual cycle in human female.

(b) Which human organs are involved in this process?
Answer:
The ovary and uterus are primarily involved in this process. But the pituitary gland also controls this cycle.

(c) Which hormones take part in this process?
Answer:
Following hormones regulate this menstrual cycle.
Pituitary hormones: Follicle Stimulating Hormone (FSH) and Luteinizing Hormone (LH).
Ovarian hormones: Estrogen and progesterone.

(d) What is the periodicity for these changes?
Answer:
The menstrual cycle shows repetitive changes every 28 to 30 days.

(e) The body of woman undergoing this process is impure, she should remain away from other people. What is your opinion about this statement? Give justification for your opinion.
Answer:
A menstruating woman is not at all with impure body. It is a natural process in which the endometrium of the uterus is sloughed off and repaired.

She should get enough rest and nutrition during this period. It is painful period in which there is a possibility of infections. Therefore, she should take ! hygienic care and rest till the bleeding persists. But blind faith and superstition to keep her away from others should not be followed.

Question 2.
Observe the diagram (Fig. 3.19) of menstrual cycle and answer the following questions:

(1) What is the period of menstruation?
Answer:
1 to 5 days is the period of menstruation.

(2) On which day does ovulation occur during menstrual cycle?
Answer:
Ovulation occurs on 14th or 15th day.

(3) During which period is corpus luteum active during menstrual cycle? Which hormones are secreted by corpus luteum ?
Answer:
Corpus luteum is active till the 28th day of menstrual cycle. During this time if there is no union of sperm and ovum, then corpus luteum degenerates. Corpus luteum secretes estrogen and progesterone.

(4) In menstrual cycle which reproductive organs undergo changes?
Answer:
Ovary and uterus undergo changes during menstrual cycle.

(5) Which period is said to be period of regeneration of endometrium?
Answer:
In menstrual cycle, days 5 to 14 are period of regeneration of endometrium.

(6) Which period is said to be period of secretions of glands in endometrium?
Answer:
Period of secretions of glands in endometrium is 15 to 28 days.

Question 3.
Observe the following picture and describe the type of reproduction shown in.

Answer:
In developed animals like wall lizard the process of regeneration is used to restore the lost parts like tail or limbs. As the reproductive system is one of the fullfledged system in the body. the process of regeneration cannot be called type of reproduction.

But some primitive organisms such as Planaria use this method for procreation. Planaria breaks up its body into two parts. Each part has the ability to develop the lost part by process of regeneration. This forms two new Planaria.

Question 4.
Answer the following questions: (March 2019)
(a) “Gender of child is determined by the male partner of couple.” Draw a diagram explaining the above statement.
Answer:

(b) Prepare a slogan for campaign against female foeticide.
Answer:

• Save the girl child.
• Daughters give lot of joy, it is not only the boy.

(c) In the following figure, explain how new fungal colonies of mucor are formed:

Answer:
Mucor is a fungus having filamentous body. The filaments bear sporangia. Mature sporangia burst and release spores. Spores germinate to form new hyphae upon getting favourable moist and warm place.

(d) Identify and state the type of reproduction represented in the above figure.
Ans. The spore formation is asexual type of reproduction seen in Mucor.

Question 5.
Write the type of asexual reproduction shown in the figure.

Answer:
The figure shows budding in yeast. Budding is the type of asexual reproduction.

Experiments:
(Try this: Text Book Pages 23 and 24)

(1) Observation of Paramoecia.
(2) Observation of yeast.
(3) Study of Hibiscus.
[For detailed information on practicals, refer to Vikas Science and Technology Experiment Book: Standard X]

Projects:

Project 1.
Use of ICT. (Textbook page no. 27)
Make an video album of pollination and show it in the class.

Project 2.
Internet is my friend. (Textbook page no. 33)
You may have read that sometimes a woman may deliver more than two offspring at a time. Collect more information from internet about reasons for such incidences.

Project 3.
Get information. (Textbook page no. 34)
Visit a public health centre nearby your place and collect the information through an interview of health officer about meaning and various methods of family planning.

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

Maharashtra State Board Class 10 Science Solutions Part 2 Chapter 7 Introduction to Microbiology

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

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

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

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

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

Question 2.
Match the pairs.

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

Question 4.
Complete the following conceptual picture.

Answer:

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

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

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

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

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

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

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

Answer:

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

Answer:

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

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

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

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

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

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

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

e. How does the bread become spongy?
Answer:

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

Project: (Do it your self)

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

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

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

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

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

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

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

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

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

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

Let’s Think: (Text Book Page No. 83)

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

Match the pairs:

Question 1.

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

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

Find the odd one out:

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

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

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

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

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

Find the correlation:

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

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

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

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

Name the following:

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

Question 2.
Emulsifiers.
Answer:
Polysaccharides and glycolipids.

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

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

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

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

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

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

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

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

Complete the charts:

Question 1.

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

Answer:

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

Question 2.

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

Answer:

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

Question 3.

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

Answer:

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

Answer the following questions:

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

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

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

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

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

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

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

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

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

Write short notes on the following:

Question 1.
Production of Yoghurt.
Answer:

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

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

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

Question 3.
Land-filling sites.
Answer:

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

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

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

Read the paragraph and answer the questions given below:

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

Questions and Answers:

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

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

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

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

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

Diagram based questions:

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

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

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

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

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

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

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

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

Activity based questions:

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

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

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

Question 3.
Observe the figure and answer the following:

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

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

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

Projects: (Do it your self)

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

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

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

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

Maharashtra State Board Class 10 Science Solutions Part 2 Chapter 9 Social Health

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

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

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

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

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

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

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

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

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

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

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

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

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

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

Question 3.
Solve the following crossword.

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

2. This app may cause the cybercrimes
Answer:
Facebook

3. A remedy to resolve stress.
Answer:
Singing

4. Requirement for stress free life.
Answer:
Goodfood

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

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

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

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

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

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

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

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

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

b. Diseases endangering the social health.
Answer:

1. AIDS
2. Tuberculosis
3. Leprosy.

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

1. Headache
2. Vision problems
3. Joint pains.

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

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

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

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

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

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

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

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

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

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

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

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

Project: (Do it your self)

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

Let’s Think: (Text Book Page No. 101)

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

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

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

Think: (Text Book Page No. 103)

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

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

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

Observe: (Text Book Page No. 103)

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

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

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

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

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

Observe: (Text Book Page No. 104)

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



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

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

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

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

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

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

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

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

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

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

Find the odd one out:

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

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

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

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

Find out the correlation:

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

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

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

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

Question 1.

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

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

Give scientific reasons:

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

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

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

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

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

Question 3.
Consuming liquor is always bad.
Answer:

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

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

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

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

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

Answer the following questions:

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

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

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

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

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

Write short notes on the following:

Question 1.
Cybercrimes.
Answer:

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

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

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

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

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

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

Paragraph based questions:

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

Questions and Answers:

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

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

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

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

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

Activity based questions:

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

Answer:
ADDICTION

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

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

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

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

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

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

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

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

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

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

(b) Causes of this problems are as under:

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

(c) Measures to eradicate this problem:

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

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

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

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

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

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

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

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

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

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

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

Projects:

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

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

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

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

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

Maharashtra State Board Class 10 Science Solutions Part 2 Chapter 2 Life Processes in Living Organisms Part – 1

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

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

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

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

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

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

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

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

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

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

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

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

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

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

TCA cycle:

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

b. Mitosis and meiosis.
Answer:
Mitosis:

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

meiosis:

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

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

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

Anaerobic respiration:

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

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

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

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

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

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

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

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

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

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

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

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

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

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



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

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

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

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

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

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



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

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

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

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

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

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

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

e. Explain the Krebs cycle with reaction.
Answer:

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

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

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

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

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

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

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

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

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

Corrected diagram:

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

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

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

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

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

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

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

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

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

Use your barain power:

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

(c) Find the full forms of FAD, FMN, NAD, NADP.
Answer:

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

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

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

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

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

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

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

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

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

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

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

Write whether the following statements are true or false:

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

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

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

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

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

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

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

Match the columns:

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

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

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

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

Find the odd one out:

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

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

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

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

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

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

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

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

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

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

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

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

Write definitions:

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

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

Name the following:

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

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

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

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

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

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

Give scientific reasons:

Question 1.
We feel exhausted after exercising.
Answer:

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

Answer the following questions in detail:

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

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

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

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

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

(c) Name fat soluble vitamins.
Answer:
Fat soluble vitamins are A, D, E and K.

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

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

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

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

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

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

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

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

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

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

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

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

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

Give explanations for the following statements:

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

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

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

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

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

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

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

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

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

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

Read the paragraph and answer the questions given below:

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

Questions and Answers :

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

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

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

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

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

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

Questions and Answers:

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

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

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

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

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

Diagram based questions:

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

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

Question 3.
Mitochondria and Krebs cycle:
Answer:

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

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

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


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

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

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

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

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

Activity based questions:

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

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

Project:

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

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

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

Maharashtra State Board Class 10 Science Solutions Part 2 Chapter 1 Heredity and Evolution

Question 1.
Complete the following diagram.

Answer:

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

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

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

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

c. Study of fossils is an important aspect of study of evolution.
Answer:
Answer:

• Fossils offer palaeontological evidence for the evolutionary process.
• Due to some natural calamities the organisms get buried during ancient times.
• The impressions and remnants of such organisms remain preserved underground. The hot lava also traps some organisms or their impressions. All such formations form fossils.
• Study of fossils help the researcher to understand the characteristics of the organisms that existed in the past.
• Carbon dating method also helps in finding out exact age of the fossil. According to the structure of earth’s crust the fossils are obtained at specific depths.
• The oldest ones are obtained at the depth while the relatively recent ones occupy the upper surface. Thus fossils of invertebrates were seen in very old Palaeozoic era. Later were seen fossils of Pisces, Amphibia and Reptilia. The Mesozoic era was dominated by reptiles while Coenozoic era showed presence of mammals.
• In this way, study of fossils unfold the evolutionary secrets.

d. There is evidences of fatal Science among chordates.
[Please read the above question as: Among different chordates there are embryological evidences.]
Answer:

• Very young embryos of fish, amphibians, reptiles, birds and mammals show quite similar structure in the early stages.
• As the further growth takes place, they acquire different patterns.
• The initial similarity between the vertebrate embryos is an evidence that during evolution, there was a common ancestor for all the vertebrate classes.
• This is called embryological evidence for vertebrate evolution.

Question 3.
complete the statements by choosing correct options from bracket.
(Genes, Mutation, Translocation, Transcription, Gradual development, Appendix)
a. The causality behind the sudden changes was understood due to ………… principle of Hugo de Vries.
Answer:
Mutation

b. The proof for the fact that protein synthesis occurs through ……….. was given by George Beadle and Edward Tatum.
Answer:
Genes

c. Transfer of information from molecule of DNA to mRNA is called as …………… process.
Answer:
Transcription

d. Evolution means ………….
Answer:
Gradual development

e. Vestigial organ ……….. present in human body is proof of evolution.
Answer:
Appendix

Question 4.
Write short notes based upon the information known to you.
a. Lamarckism.
Answer:
(1) Lamarckism consists of two theories which were proposed by Jean Baptiste Lamarck. These are as follows: (a) Use and disuse of the organs (b) Inheritance of acquired characters.
(2) In theory of use and disuse of organs, Lamarck says : The characters of organs develop because specific activities that the organisms perform. If such organ is not used it gets degenerated. Thus the morphological changes take place due to activities or inactivity of a particular organism.
(3) To emphasise this theory, he quoted following examples. Due to constant extension of neck to eat foliage from the top of the trees, giraffe’s neck became long. Similarly blacksmith has strong arms due to constant work. Flightless ostrich and emu did not fly and hence their wings became useless. Aquatic birds like swan and duck made their feet suitable for swimming by living in water. Snake lost limbs as it tried burrowing mode.
(4) Such acquired characters are passed from one parental generation to the offspring. This is called inheritance of acquired characters.
(5) The theory of inheritance of acquired characters is not accepted as such transmission of acquired character does not take place. Only genetic characters are transmitted.

b. Darwin’s theory of natural selection.
Answer:

• Charles Darwin proposed the theory of natural selection after making many observations on different specimens. He published a concept ‘Survival of the fittest’.
• Darwin explains this concept as follows: All the organisms reproduce prolifically. Therefore, there is always a competition for food, mate, etc. Only adaptations for sustaining this struggle.
• Natural selection plays important role by selecting only those organisms which are fit to live. Those that do not have better adaptations, perish. Selected sustaining organisms then perform reproduction and form new species in a very long period of time.
• Darwin published his views in the book titled ‘Origin of Species’.

c. Embryology.
Answer:

• Embryology is the study of developing embryos.
• These embryos in their initial stages are very similar to each other.
• These similarities decrease later in the development.
• This similarity in initial stages indicate that these vertebrates have originated from a common ancestor.
• In evolutionary science, comparative study of embryos of various vertebrates provide evidence for evolution.

d. Evolution.
Answer:

• The sequential changes in the groups of living organisms that take place very gradually is called evolution.
• Evolution is also described as the formation of new species due to natural selection.
• The process of evolution takes millions of years for development and speciation of different organisms.
• Changes in stars and planets in space and the changes in biosphere occurring on the Earth are all included under study of evolution.
• Due to evolution organisms become fit, biodiversity is increased, and new species are created.
• Different scientists have put forth theories to explain the process of evolution. Among these Charles Darwin’s theory of natural selection and speciation is accepted worldwide.

e. Connecting link.
Answer:
Some living organisms possess some characters in them which are the distinctive features of different groups or phyla. Such individuals connect these two groups by sharing the characters of both and hence they are known as connective links.

Examples: (1) Peripatus: Peripatus is the connecting link between Annelida and Arthropoda. It shows characters of both animal phyla. Like annelid worm, it shows segmented body, thin cuticle and parapodia. Like an arthropod, it shows open circulatory system and tracheal system for respiration.
(2) Duck Billed platypus: This is a connecting link between reptiles and mammals. Like reptiles it lays eggs but like mammals it has mammary glands and hairy skin.
(3) Lung fish: Lung fish is a connecting link between fishes and amphibians. Though a fish, it shows lungs for respiration as in amphibian animals.
(4) Connecting links indicate the direction and hierarchy of evolution.

Question 5.
Define heredity. Explain the mechanism of hereditary changes.
Answer:
(1) Heredity: Heredity is the process by which the biological characters from parental generation are transmitted to the next generation through genes.

(2) The mechanism of hereditary changes:

• Mutation: Sudden change in the parental DNA can cause mutations. This results into changes in the hereditary characters.
• At the time of meiosis, the crossing over takes place. This creates new recombination of the genetic information. Therefore, the haploid gametes produced carry changed hereditary characters.

Question 6.
Define vestigial organs. Write names of some vestigial organs in human body and write the names of those animals in whom same organs are functional.
Answer:

• Vestigial organs are degenerated or underdeveloped organs of organisms which do not perform any function.
• According to the principle of natural selection, such organs are on the verge of disappearance. But it takes many millions of years for its complete vanishing.
• The vestigial organs in one animal may be of use but to other kind of the animal as they still perform regular functions.
• Appendix is vestigial for humans, it does not perform any function but in ruminant animals it is concerned with digestion.
• Ear muscles are vestigial for us but in monkeys and cattle they are functional.
• Names of vestigial organs in human body-Appendix, tail-bone or coccyx, wisdom teeth and body hair.

Question 7.
Answer the following questions.
a. How are the hereditary changes responsible for evolution?
Answer:
Hereditary characters are transmitted from parental generation to the offspring. These characters are maintained through inheritance. But the genes which are beneficial for the organisms in helping them to adapt to the environment are transmitted to the next generations in a greater proportion. This happens due to natural selection.

The process of evolution happens at a very slow pace. The favourable genes are preserved in the species as they bring about better survival of the individuals. Such individual reproduces more efficiently and evolve. The individuals with unfavourable genes are not selected by nature and are thus removed from the population through natural death. The fuel for evolution is thus truly supplied by the hereditary changes.

b. Explain the process of formation of complex proteins.
Answer:
The proteins are synthesised in following steps, viz. transcription, translation and translocation. Protein synthesis takes place according to the sequence of nucleotides present on the DNA molecule with the help of RNA molecules. This is known as central dogma of protein synthesis.

1. Transcription: In the process of transcription, mRNA is produced as per the nucleotide sequence on the DNA. For this the two strands DNA are separated. Only one strand participates in the formation of mRNA. The sequence of nucleotides which is complementary to that of present on DNA is copied on mRNA. Instead of thymine present in DNA, uracil is added on the mRNA. Transcription takes place in nucleus but the mRNA leaves nucleus, carries the genetic code and enters the cytoplasm. This genetic code is always in triplet form arid hence is known as triplet codon. The code for each amino acid always consists of three nucleotides.

2. Translation: Each mRNA may carry thousands of codons. But each codon is specific for only one amino acid. The tRNA molecule brings the required amino acid as per the code present on mRNA. There is anticodon on each tRNA which is complementary to the codon on mRNA. This process is known as translation.

3. Translocation: In translocation, the ribosome keeps on moving from one end of mRNA molecule to other end by distance of one triplet codon. While this process is taking place, rRNA, helps in joining the amino acids together by peptide bonds. The peptide chains later come together to form complex protein molecules.

c. Explain the theory of evolution and mention the proof supporting it.
Answer:
1. Theory of evolution:

• According to the theory of evolution, first living material was in the form of protoplasm which was formed in ocean.
• Gradually, it gave rise to unicellular organisms. Changes took place in these unicellular organisms which made them evolve into larger and more complex organisms.
• All evolutionary changes were very slow and gradual taking about 300 crore years to happen.
• Different types of organisms were developed as the changes and development that occurred in living organisms wefts all round and multi-dimensional.
• Hence, this overall process of evolution is called organizational and progressive.
• Variety of plants and animals developed from the ancestors having different structural and functional organization during the process of evolution.

2. Proof here means evidences of evolution.
These evidences are as follows:

• Morphological evidences
• Anatomical evidences
• Vestigial organs
• Palaentological evidences
• Connecting links
• Embryological evidences.

d. Explain with suitable examples importance of anatomical evidences in evolution. (July 2019)
Answer:

• There are similarities in the structure and anatomy of different animal groups. E.g. human hand, forelimb of bull, patagium of bat and flipper of whale are all similar in their internal anatomy. There is similarity in the bones and joints of all these specimens.
• External morphology does not show any similarity. Use of each of the organ is also different in different animals. Structurally, they may not be related.
• However, the similarities in the anatomy is an evidence that they may have a common ancestor.
• In this way, the anatomical evidence throws light on the process of evolution.

e. Define fossil. Explain importance of fossils as proof of evolution.
Answer:

• Fossils offer palaeontological evidence for the evolutionary process.
• Due to some natural calamities the organisms get buried during ancient times.
• The impressions and remnants of such organisms remain preserved underground. The hot lava also traps some organisms or their impressions. All such formations form fossils.
• Study of fossils help the researcher to understand the characteristics of the organisms that existed in the.past.
• Carbon dating method also helps in finding out exact age of the fossil. According to the structure of earth’s crust the fossils are obtained at specific depths.
• The oldest ones are obtained at the depth while the relatively recent ones occupy the upper surface. Thus fossils of invertebrates were seen in very old Palaeozoic era. Later were seen fossils of Pisces, Amphibia and Reptilia. The Mesozoic era was dominated by reptiles while Coenozoic era showed presence of mammals.
• In this way, study of fossils unfold the evolutionary secrets.

f. Write evolutionary history of modern man.
Answer:
(1) Ancestors of humans developed from animals which resembled lemur like animals.
(2) Around seven crore years ago, monkey-like animals evolved from some of these lemur like animals.
(3) Then after about 4 crore years ago, in Africa the tails of these monkey like creatures very gradually disappeared.
(4) Simultaneously, there was enlargement in their body and brain volume too. The hands also improved and were provided with opposable thumb. In this way, ape-like animals were evolved.
(5) These ape-like animals independently gave rise to two lines of evolution, one giving rise to apes like gibbon and orangutan in the South and North-East Asia and gorilla and chimpanzee which stayed in Africa around 2.5 crores of years ago.
(6) The other line of evolution gave rise to human like animals around 2 crore years ago.
(7) The climate became dry and this resulted into reduction of forest cover. This made arboreal apes to descend on the land and start terrestrial mode.
(8) Due to this, there were changes in the pefvic
girdle and vertebral column. The hands were also freed from locomotion and thus they became more manipulative.
(9) Later, journey of hominoid species started from around 2 crores years ago. The first record of human like animal is ‘Ramapithecus’ ape from East Africa.
(10) Ramapithecus → Australopithecus → Neanderthal man → Cro-Magnon are the important steps in human evolution.
(11) Neanderthal man was said to be the first wise man. The increasing growth of brain made man more and more intelligent and thinking animal.
(12) Later, more than biological evolution, it was cultural evolution, when man started agriculture, animal , rearing. There was development of civilizations, arts and science etc. About 200 years ago there were industrial inventions and thus man now rules the earth.

Project:

Project 1.
Make a presentation on human evolution using various computer softwares and arrange a group disscussion over it in the class room.

Project 2.
Read the book – ‘Pruthvivur Manus Uparcich’ written by Late Dr. Sureshchandra Nadkarni and note your opinion on evolution.

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

Question 1.
Which component of the cellular nucleus of living organisms carries hereditary characters?
Answer:
The chromosomes made up of nucleic acids and proteins, present in the nucleus of the cell are the components that carry hereditary characters in living organisms.

Question 2.
What do we call the process of transfer of physical and mental characters from parents to the progeny?
Answer:
The process of transfer of physical and mental characters from parents to the progeny is called inheritance or heredity.

Question 3.
Which are the components of the DNA molecule?
Answer:
DNA molecule is made up of two helical strands consisting of deoxyribose sugar, phosphoric acid and pairs of nitrogenous bases. These three together is called a nucleotide.

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

Question 1.
Darwin has published a book titled …………..
(a) Natural selection
(b) Mutation
(c) Fall of a sparrow
(d) Origin of species
Answer:
(d) Origin of species

Question 2.
The …………. man evolved about 50 thousand years ago.
(a) Cro Magnon
(b) Neanderthal
(c) Java man
(d) Ramapithecus
Answer:
(a) Cro Magnon

Question 3.
About 10 thousand years ago, ………….. started to practise agriculture.
(a) Gorilla
(b) wise man
(c) Ramapithecus
(d) Australopithecus
Answer:
(b) wise man

Question 4.
………………. can be considered as the first example of wise-man.
(a) Australopithecus
(b) Ramapithecus
(c) Cro Magnon
(d) Neanderthal man
Answer:
(d) Neanderthal man

Question 5.
………. is a connecting link between Annelida and Arthropoda. (March 2019)
(a) Duck-billed platypus
(b) Peripatus
(c) Lung fish
(d) Whale
Answer:
(b) Peripatus

Question 6.
………… years ago human brain was sufficiently evolved to call him wise man.
(a) 50,000
(b) 30,000
(c) 20,000
(d) 10,000
Answer:
(a) 50,000

Question 7.
The process by which the gene in the nucleotide suddenly changes its position is called ………. (Board’s Model Activity Sheet)
(a) translation
(b) translocation
(c) mutation
(d) transcription
Answer:
(c) mutation

Question 8.
…………. is not the vestigial organ in the human body. (Board’s Model Activity Sheet)
(a) appendix
(b) Coccyx
(c) Canine
(d) Wisdom teeth
Answer:
(c) Canine

Write whether the following statements are true or false with proper justification for your answer:

Question 1.
It takes thousands of years for a useful structure to disappear.
Answer:
False. (The useful structures of the body do not disappear. The functioning of the body is easier due to such organs. It takes thousands of years for a functionless organ to disappear.)

Question 2.
Dr. Har Govind Khorana was awarded Nobel prize for his invention and publication in the journal Radio carbon.
Answer:
False. (Willard Libby was awarded Nobel prize for his invention and publication in the journal Radio carbon.)

Question 3.
Mesozoic era was dominated by variety of mammals.
Answer:
False. (Mesozoic era dominated by variety of reptiles.)

Question 4.
It seems that invertebrates have been slowly originated from vertebrates.
Answer:
False. (Vertebrates have been slowly originated from invertebrates in course of evolution. The primitive type of organisms always give rise to complex life forms. The invertebrates from Palaeozoic era gradually gave rise to vertebrates.)

Question 5.
The decaying process of C-12 occurs continuously from the dead remains of living organisms.
Answer:
False. (The decaying process of C-14 occurs continuously from the dead remains of living organisms. C-12 is not radioactive and hence it does not show decaying process.)

Question 6.
The theory of natural selection which mentions ‘Survival of fittest’ is given by Lamarck.
Answer:
False. (The theory of natural selection which mentions ‘Survival of fittest’ is given by Darwin.)

Question 7.
Changes acquired during life time are transferred to next generation.
Answer:
False. (Changes acquired during life time are not heritable. They are not transferred to next generation. Only the genes are transferred to the next generation.)

Question 8.
Each species grows in specific geographical conditions and has specific food, habitat, reproductive ability and period.
Answer:
True. (Each species has specifically evolved characters due to evolution and speciation.)

Question 9.
Humans walking with upright posture were confined to Africa only during prehistoric period.
Answer:
False. (Humans walking upright existed in Africa and China, Indonesia of Asian continent too.)

Question 10.
Industrial society was established about 200 years ago.
Answer:
True. (After the development and specialization of human brain, he started indulging in science and technology. Before; this period the idea of industrialization was not existing.)

Match the columns:

Question 1.

Scientist	Discovery
(1) Johann Gregor Mendel	(a) Chromosomes of grasshopper
(2) Hugo de Vries	(b) DNA is genetic material
	(c) Pioneer of the modern genetics
	(d) Mutational theory

Answer:
(1) Johann Gregor Mendel – Pioneer of the modern genetics.
(2) Hugo de Vries – Mutational theory.

Question 2.

Scientist	Discovery
(1) Walter, Sutton	(a) Chromosomes of grasshopper
(2) Mclyn McCarthy	(b) DNA is genetic material
	(c) Pioneer of the modern genetics
	(d) Mutational theory

Answer:
(1) Walter, Sutton – Chromosomes of grasshopper.
(2) Mclyn McCarthy – DNA is genetic material.

Question 3.

Evidences of evolution	Examples
(1) Morphological evidences	(a) Duck billed Platypus and Peripatus
(2) Anatomical evidences	(b) Remnants and impressions
	(c) Human hand and fore limb of bull
	(d) Shape and venation of leaf

Answer:
(1) Morphological evidences – Shape and venation of leaf.
(2) Anatomical evidences – Human hand and fore limb of bull.

Question 4.

Evidences of evolution	Examples
(1) Palaeontological evidences	(a) Duck billed Platypus and Peripatus
(2) Connecting links	(b) Remnants and impressions
	(c) Coccyx and wisdom tooth
	(d) Human hand and fore limb of cat

Answer:
(1) Palaeontological evidences – Remnants and impressions.
(2) Connecting links – Duck billed Platypus and Peripatus.

Find the odd one out:

Question 1.
Transcription, Translation, Translocation, Mutation
Answer:
Mutation. (All others are stages of protein synthesis.)

Question 2.
Bones of the hands, structure of nostrils, position of eyes, structure of ear pinnae
Answer:
Bones of the hands. (All the others are morphological evidences.)

Question 3.
Venation, Shape of seeds, Leaf petiole, Leaf shape
Answer:
Shape of seeds. (All the others are morphological evidences in plants.)

Question 4.
Human hand, wing of cockroach, forelimb of bull, flipper of whale
Answer:
Wing of cockroach. (All others are anatomical evidences, they are homologous organs.)

Identify the correlation between the first two words and suggest the suitable words in the fourth place:

Question 1.
mRNA : Transcription :: tRNA :…………
Answer:
Translation

Question 2.
Peripatus : Connecting link :: Appendix :……….
Answer:
Vestigial organs

Question 3.
Open circulatory system : Arthropods :: Thin cuticle and parapodia :………..
Answer:
Annelida

Question 4.
Between Annelida and Arthropoda : Peripatus ::……….: Lungfish
Answer:
Pisces/Fish and Amphibia

Question 5.
Theory of natural selection : Charles Robert Darwin :: Theory of inheritance of acquired characters :…………
Answer:
Jean Baptiste Lamarck

Question 6.
Survival of fittest : Darwin :: Acquired characters :……….
Answer:
Lamark

Question 7.
Wisdom teeth : Vestigial organs :: Lungfish :………..
Answer:
Connecting link.

Define the following:

Question 1.
Heredity.
Answer:
The transfer of biological characters from one generation to another through genes is called heredity.

Question 2.
Transcription.
Answer:

Question 3.
Translation.
Answer:
The process of bringing tRNA possessing anticodon that is complementary to the codon on mRNA for protein synthesis is called translation.

Question 4.
Translocation.
Answer:
The process of movement of the ribosome from one end of mRNA to other end by the distance of one triplet codon is called translocation.

Question 5.
Mutation.
Answer:
Sudden and drastic change that occurs in the genetic material is called mutation.

Question 6.
Species.
Answer:
The group of organisms that cap produce fertile individuals through natural reproduction is called a species.

Name the following:

Question 1.
Three Scientists who proved that except viruses, all living organisms have DNA as genetic material.
Answer:
Oswald Avery, Mclyn McCarthy and Colin MacLeod.

Question 2.
Genetic disorder caused due to mutation:
Answer:
Sickle cell anaemia.

Question 3.
Fish that can breathe with help of lungs:
Answer:
Lung fish.

Question 4.
Vestigial organs in human beings:
Answer:
Appendix, tail-bone or coccyx, wisdom teeth and body hair.

Question 5.
Important stages in the journey of human evolution:
Answer:

• Animals like Lemur
• Egyptopithecus
• Dryopithecus
• Ramapithecus
• Australopithecus
• Skilled Human
• Homo erectus i.e. Man with erect posture
• Neanderthal man
• Cro-Magnon man.

Distinguish between the following:

Question 1.
Transcription and Translation.
Answer:
Transcription:

1. In the process of transcription, the sequence of nucleotides present on the DNA molecule is copied
   and carried to the cytoplasm by mRNA.
2. The process of transcription takes place in nucleus.
3. During transcription, RNA is produced from DNA.
4. Only mRNA takes part in transcription.

Translation:

1. In the process of translation, the specific amino acids are picked up according to the codons brought by mRNA.
2. The process of translation takes place in ribosomes located in cytoplasm.
3. During translation, proteins are produced with the help of RNA.
4. mRNA, tRNA and rRNA take part in translation.

Question 2.
Ape and Human.
Answer:
Ape:

1. Brain of the apes is smaller in size.
2. Ape cannot walk upright.
3. Ape is less intelligent as compared to human.
4. Apes are arboreal in their habitat and they spend more time on the trees.
5. The forelimbs of ape are longer than the hind limbs.

Human:

1. Brain of humans is larger in size.
2. Humans can walk upright.
3. Human is considered to be the most intelligent animal.
4. Humans are terrestrial in their habitat. They cannot stay on the trees.
5. The forelimbs of humans are shorter than the hind limbs.

Give scientific reasons:

Question 1.
Some of the characters of parents are seen in their offspring.
Answer:

• The parental genes are transferred to their progeny through male and female gametes.
• These genes carry hereditary characters.
• Since they are transmitted from the parents to their offspring, one can see the parental characters in their offspring.

Question 2.
Darwin’s work on evolution has been a milestone.
Answer:
(1) Darwin has proposed two very important theories of evolution, viz. Theory of natural selection and Theory of origin of species.
(2) The evolution has taken place on the earth for last many crores of years.
(3) The exact nature and process of these evolutionary changes become clear after studying Darwinism. (4) The observations made by Darwin at that time are now tested according to the modern development in science and are found to be correct. Thus, his work is said to be a milestone.

Question 3.
Peripatus is said to be a connecting link between Annelida and Arthropoda.
Answer:

• Peripatus shows segmented body, thin cuticle, and parapodia-like organs.
• These characters are typical of Annelids.
• Similarly, it also shows tracheal respiration and open circulatory system which is a characteristic feature of Arthropods.
• Since Peripatus shares both these characters, it is said to be a connecting link between j Annelida and Arthropoda.

Question 4.
Vertebrates have been slowly originated from invertebrates.
Answer:

• When the carbon dating method was used to assess the age of fossils, it was understood that invertebrates were present on the earth much before the vertebrates.
• The fossils of invertebrates are present in lower layers of earth’s strata.
• They were seen in Palaeozoic era of geological time period. Vertebrates dominated during Coenozoic era.
• Their fossils are seen in the upper strata of the earth’s crust.
• The structural complexity also increased in vertebrates. All these facts indicate that Vertebrates have slowly originated from invertebrates.

Question 5.
During human evolution the hands became available for use.
Answer:

• During human evolution, the climate of earth started becoming dry.
• This resulted in loss of forest cover.
• The apes which were arboreal on the trees thus descended and started walking on land.
• The lumbar bones underwent change and the apes started walking upright on the grasslands.
• The vertebral column also underwent change. Due to upright posture the forelimbs were freed from locomotion.
• The legs started bearing the weight of the body and the hands became available for use.

Read the following statements and justify the same in your own words with the help of suitable examples:

Question 1.
Geographical and reproductive isolation of organisms gradually leads to speciation.
Answer:

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

Question 2.
Study of fossils is an important aspect of study of evolution.
Answer:
(1) Fossils offer palaeontological evidence for the evolutionary process.
(2) Due to some natural calamities the organisms get buried during ancient times.
(3) The impressions and remnants of such organisms remain preserved underground. The hot lava also traps some organisms or their impressions. All such formations form fossils.
(4) Study of fossils help the researcher to understand the characteristics of the organisms that existed in the.past.
(5) Carbon dating method also helps in finding out exact age of the fossil. According to the structure of earth’s crust the fossils are obtained at specific depths.
(6) The oldest ones are obtained at the depth while the relatively recent ones occupy the upper surface. Thus fossils of invertebrates were seen in very old Palaeozoic era. Later were seen fossils of Pisces, Amphibia and Reptilia. The Mesozoic era was dominated by reptiles while Coenozoic era showed presence of mammals.
(7) In this way, study of fossils unfold the evolutionary secrets.

Question 3.
There is evidences of fatal Science among chordates.
[Please read the above question as: Among different chordates there are embryological evidences.]
Answer:

• Very young embryos of fish, amphibians, reptiles, birds and mammals show quite similar structure in the early stages.
• As the further growth takes place, they acquire different patterns.
• The initial similarity between the vertebrate embryos is an evidence that during evolution, there was a common ancestor for all the vertebrate classes.
• This is called embryological evidence for vertebrate evolution.

Question 4.
Human evolution began approximately 7 crore years ago.
Answer:

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

Answer the following questions:

Question 1.
Answer the following questions: (March 2019)
(a) What do you mean by central dogma?
Answer:
Information about protein synthesis is present in DNA. As per this information, proteins are produced by DNA through RNA molecules. This is called central dogma.

(b) What is transcription?
Answer:
The process of synthesis of mRNA as per the nucleotide sequence present in DNA is called transcription. The nucleotide sequence on mRNA is complimentary to that of the single DNA strand used in synthesis. Instead of thymine, mRNA possesses uracil.

(c) What is meant by triplet codon?
Answer:
The code for each amino acids always consists of three nucleotides which is known as triplet codon.

Question 2.
Which animal is called a connecting link between Reptiles and Mammals? (Board’s Model Activity Sheet)
Answer:
Duck billed platypus is called a connecting link between Reptiles and Mammals.

Question 3.
In which way is science of heredity useful these days?
Answer:
The science of heredity is useful in the following ways:

• For diagnosis of hereditary disorders.
• For treatment of hereditary disorders
• For prevention of hereditary disorders
• For production of hybrid varieties of animals and plants
• For using microbes in the industrial processes.

Question 4.
What is meant by carbon dating method?
Answer:
(1) Carbon dating method is technique used for determining the age of fossils.
(2) After the death of the organisms, their consumption of carbon stops. But right from that moment the decaying process of C-14 occurs continuously.
(3) This results in change in the ratio between C-14 and C-12. C-12 is not radioactive as C-14.
(4) Thus the time passed since the death of a plant or animal is calculated by measuring the radioactivity of C-14 and ratio of C-14 to C-12 present in their body.
(5) The points noted during carbon dating are:

• The period after the organism has been dead.
• The activity of C-14 in the dead organism.
• Ratio between C-14 and C-12.

Question 5.
Answer the following questions:
(a) Describe briefly the Darwin’s theory of natural selection.
Answer:
Charles Darwin (1809-1882) proposed the theory of natural selection.
Theory of natural selection: ‘The survival of fittest’, i.e., organisms which are fit for survival, evolve while those that are not, perish. The natural selection thus acts to produce new species.

(b) What were the objections raised against Darwinism?
Answer:
Objections raised against Darwinism:

1. There are other factors too for evolution and just not the Natural Selection.
2. Arrival of useful and useless modifications were not explained by Darwin, though he said about the survival of the fittest.
3. He has not given any explanation about slow changes and abrupt changes occurring during evolution.

(c) Which book was published by Darwin to explain this theory? (Board’s Model Activity Sheet)
Answer:
Charles Darwin wrote the book ‘Origin of Species’.

Question 6.
What were the objections raised against Darwinism?
Answer:
Some of the main objections raised against Darwinism are as follows:

• There are other factors too for evolution and just not the Natural Selection.
• Arrival of useful and useless modifications were not explained by Darwin, though he said about the survival of the fittest.
• He has not given any explanation about slow changes and abrupt changes occurring during evolution.

Question 7.
Answer the following questions:
(a) Explain in brief-Lamarck’s principle of ‘use or disuse of organs’.
Answer:
The theory of use and disuse of organs says that the morphological characters of organism develop because of specific activities that the organisms perform. If some organ is not used it gets degenerated. If excessively, used, it develops. Thus, the morphological changes take place due to activities or non-working of a particular body parts in an organism.

(b) Give two examples.
Answer:
Due to constant extension of neck to eat foliage from the top of the trees, giraffe’s neck became long. Similarly, blacksmith has strong arms due to constant work. The flightless ostrich and emu did not fly and hence their wings became useless. Aquatic birds like swan and duck made their feet suitable for swimming by living in water. Snake lost limbs as it tried burrowing mode.

(c) What are acquired characters?
Answer:
Acquired characters are those characters which are obtained during the life time by any organism and passed on to next generations.

Write short notes:
(OR)
Write short notes based upon the information known to you:

Question 1.
Theory of evolution.
Answer:

• According to the theory of evolution, first living material was in the form of protoplasm which was formed in ocean.
• Gradually, it gave rise to unicellular organisms. Changes took place in these unicellular organisms which made them evolve into larger and more complex organisms.
• All evolutionary changes were very slow and gradual taking about 300 crore years to happen.
• Different types of organisms were developed as the changes and development that occurred in living organisms was all round and multi-dimensional.
• Hence, this overall process of evolution is called organizational and progressive.
• Variety of plants and animals developed from the ancestors having different structural and functional organization during the process of evolution.

By choosing appropriate words given in the bracket, complete the paragraph:

Question 1.
(translation, anticodon, tRNA, mRNA, amino acids, triplet codon, transcription, DNA)
The …….. formed in nucleus comes in cytoplasm. It brings in the coded message from DNA. The message contains the codes for amino acids. The code for each amino acid consists of three nucleotides. It is called as ‘………..’. Each mRNA is made up of thousands of triplet codons. As per the message on mRNA, ……… are supplied by the ………. For this purpose, tRNA has ‘…………’ having complementary sequence to the codon on mRNA. This is called ‘………..’.
Answer:
The mRNA formed in nucleus comes in cytoplasm. It brings in the coded message from DNA. The message contains the codes for amino acids. The code for each amino acid consists of three nucleotides. It is called as ‘triplet codon’. Each mRNA is made up of thousands of triplet codons. As per the message on mRNA, amino acids are supplied by the tRNA. For this purpose, tRNA has ‘anticodon’ having complementary sequence to the codon on mRNA. This is called ‘translation’.

Question 2.
(Cultural, agriculture, fire, brain, Cro-Magnon, Homo sapiens, Neanderthal)
Evolution of upright man continued in the direction of developing its ………. for the period of about 1 lakh years and meanwhile he discovered the ………. Brain of man, 50 thousand years ago had been sufficiently evolved to the extent that it could be considered as member of the species ………… Neanderthal man can be considered as the first example of wise-man. The ……….. man evolved about 50 thousand years ago and afterwards, this evolution had been faster than the earlier. About 10 thousand years ago, wise-man started to practise the ………. It started to rear the cattle-herds and established the cities. ………..development took place later.
Answer:
Evolution of upright man continued in the direction of developing its brain for the period of about 1 lakh years and meanwhile he discovered the fire. Brain of man 50 thousand years ago had been sufficiently evolved to the extent that it could be considered as member of the species Homo sapiens. Neanderthal man can be considered as the first example of wise-man. The Cro-Magnon man eyolved about 50 thousand years ago and afterwards, this evolution had been faster than the earlier. About 10 thousand years ago, wise-man started-to practise the agriculture. It started to rear the cattle-herds and established the cities. Cultural development took place later.

Read the paragraph and answer the questions given below:

With the help of RNA, the genes present in the form of DNA participate in the functioning of cell and thereby control the structure and functioning of the body. Information about protein synthesis is stored in the DNA and synthesis of appropriate proteins as per requirement is necessary for body. These proteins are synthesized by DNA through the RNA. This is called ‘Central Dogma’. mRNA is produced as per the sequence of nucleotides on DNA. Only one of the two strands of DNA is used in this process. The sequence of nucleotides in mRNA being produced is always complementary to the DNA strand used for synthesis. Besides, there is uracil in RNA instead of thymine of DNA. This process of RNA synthesis is called ‘transcription’.

Questions and Answers:

Question 1.
Which part of the cell control the structure and functioning of the body?
Answer:
Genes present in the form of DNA along with RNA control the structure and functioning of the body.

Question 2.
How is a specific protein synthesised in the cell?
Answer:
The information of protein synthesis is stored in the DNA which is utilised as per the requirement of the body. Later the proteins are synthesised by DNA through the RNA.

Question3.
What is the similarity between mRNA and DNA?
Answer:
The sequence of nucleotides on DNA is copied on mRNA. The nucleotide sequence on mRNA is thus complementary to DNA.

Question 4.
Give one difference between RNA and DNA.
Answer:
RNA has uracil instead of thymine which is present in DNA.

Question 5.
Define central dogma.
Answer:
Central dogma is the concept that proteins are synthesised by DNA through the RNA.

Diagram-based questions:

Question 1.
Observe the figure 1.3 of transcription given on page 9 in this chapter and answer the following questions:

(1) What is the sequence of nucleotides present on one strand of the DNA?
Answer:
A T G C A A T T

(2) According to the above sequence on DNA, what will be the transcribed sequence on the mRNA molecule?
Answer:
U A C G U U A A

(3) Which enzyme is taking part in the above process of transcription?
Answer:
RNA polymerase takes part in the process of transcription.

Question 2.
Observe the figure 1.5 of translation and translocation, given on page 9 this chapter and answer the following questions:

(1) Which is the initiation codon? Where is it present?
Answer:
AUG is the initiation codon, which is present on the mRNA.

(2) What are the types of RNA present inside the ribosome? Which triplet codon is present on it?
Answer:
There are two molecules of tRNA present inside the ribosome. The triplet codons present on them are UAC and AAG respectively.

(3) Which genetic code is present on mRNA that is leaving the nucleus? What must be the sequence on the DNA to have such code on mRNA?
Answer:
The mRNA that leaves the nucleus has genetic code: A U G U U C A A A
The genetic code on DNA therefore should be as follows: T A C A A G T T T

Question 3.
Observe the figure 1.6 given on page 10 from this chapter. Answer the following question based on your observations:

What is the significance of this figure from the viewpoint of evolution? Explain in brief.
Answer:
In the figure, the process of mutation is shown. The original nucleotide sequence of TGC is replaced by new mutated sequence GAT. The change in the nucleotide sequence will change the DNA.

This will result in the change in genes and then changing the hereditary characters. Due to such change in genes, the evolution proceeds. The mutation so formed can be minor or major. The greater the impact of the change, the evolution takes place rapidly. The mutation thereby produce recombinations leading to diversity.

Question 4.
Observe the picture and answer the following questions:

(1) Which evidence of evolution is shown in the picture?
Answer:
Embryological evidences of evolution are shown in this picture.

(2) What can be proven with this proof?
Answer:
The similarities in the initial embryonic stages of different vertebrates shows that there was a common origin of all of them. Thus embryological evidences prove that there was common vertebrate ancestor.

(3) Give one more example of evidence of evolution.
Answer:
Palaeontological evidences such as vestigial organs and connecting links are another examples of evolutionary evidences.

Question 5.
Which concept/theory do you remember after seeing this picture of Giraffes? Describe it in brief.

Answer:

• The picture is based on the Lamarck’s principle of ‘use and disuse of organs’.
• The morphological characters of organism develop because of specific activities that the organisms perform.
• If some organ is not used it gets degenerated. If excessively used, it develops further.
• Thus, the morphological changes take place due to activities or non-working of a particular body parts in an organism. Due to constant extension of neck to eat foliage from the top of the trees, giraffe’s neck became long.

Activity-based Questions:

Try this: (Text Book Page No. 4)

Observe the above images and note the similarities between given animal images and plant images.
Answer:
The above pictures of the animals show similarities such as structure of mouth, position of eyes, structure of nostrils and ear pinnae and body fur. In pictures of plants there are similarities in characters like leaf shape, leaf venation, leaf petiole, etc.
These above morphological evidences show that there may be a common ancestor for all of the species shown.

Observe and Discuss:

Question 1.
Observe the pictures given below. (Text Book Page No. 5)

Answer:
(1) Fossils offer palaeontological evidence for the evolutionary process.
(2) Due to some natural calamities the organisms get buried during ancient times.
(3) The impressions and remnants of such organisms remain preserved underground. The hot lava also traps some organisms or their impressions. All such formations form fossils.
(4) Study of fossils help the researcher to understand the characteristics of the organisms that existed in the.past.
(5) Carbon dating method also helps in finding out exact age of the fossil. According to the structure of earth’s crust the fossils are obtained at specific depths.
(6) The oldest ones are obtained at the depth while the relatively recent ones occupy the upper surface. Thus fossils of invertebrates were seen in very old Palaeozoic era. Later were seen fossils of Pisces, Amphibia and Reptilia. The Mesozoic era was dominated by reptiles while Coenozoic era showed presence of mammals.
(7) In this way, study of fossils unfold the evolutionary secrets.

Question 2.
Observe the pictures given and discuss the characters observed. (Text Book Page No. 6)

Answer:
Some living organisms possess some characters in them which are the distinctive features of different groups or phyla. Such individuals connect these two groups by sharing the characters of both and hence they are known as connective links.

Examples: (1) Peripatus: Peripatus is the connecting link between Annelida and Arthropoda. It shows characters of both animal phyla. Like annelid worm, it shows segmented body, thin cuticle and parapodia. Like an arthropod, it shows open circulatory system and tracheal system for respiration.
(2) Duck Billed platypus: This is a connecting link between reptiles and mammals. Like reptiles it lays eggs but like mammals it has mammary glands and hairy skin.
(3) Lung fish: Lung fish is a connecting link between fishes and amphibians. Though a fish, it shows lungs for respiration as in amphibian animals.
(4) Connecting links indicate the direction and hierarchy of evolution.

Project: (Do it your self)

Project 1.
Internet is my friend: (Text Book Page No. 3)
Collect the information from the internet about Big-Bang theory related with the formation of stars and planets and present it in your class.

Project 2.
Use of ICT: (Text Book Page No. 4)
Collect the information of geological dating and present it in the classroom.

Project 3.
Use of ICT: (Text Book Page No. 5)
Find how the vestigial organs in certain animals are functional in others. Present the information in your class and send it to others.

Project 4.
Internet is my friend: (Text Book Page No. 8)
Collect the pictures and information of various species of monkeys from internet.

Balbharti Maharashtra State Board Class 10 Science Solutions Part 2 Chapter 4 Environmental management Notes, Textbook Exercise Important Questions and Answers.

Maharashtra State Board Class 10 Science Solutions Part 2 Chapter 4 Environmental management

Question 1.
Reorganize the following food chain. Describe the ecosystem to which it belongs.
Grasshopper – Snake – Paddy field – Eagle – Frog.
Answer:

• Correct food chain: Paddy field → Grasshopper → Frog → Snake → Eagle.
• Such food chain is seen in the terrestrial ecosystem. There are many biotic factors in the terrestrial ecosystem, such as insects, birds, mammals etc.
• The above example mentions about paddy field, so it must be in vicinity of coastal lands. There is water logging in the paddy fields. Therefore, it offers a habitat to the frogs.
• In the above example, paddy fields are producers in the ecosystem. The primary consumer is grasshopper. Secondary consumer is frog, tertiary consumer is snake and the apex consumer is eagle. On every trophic level the bacteria, fungi and some scavenging worms can act as the decomposers.
• In this ecosystem. the solar energy is transferred from the paddy crops to eagle in a step wise food
  chain.

Question 2.
Explain the statement – ‘We have got this Earth planet on lease from our future generations and not as an ancestral property from our ancestors.’
Answer:

• The earth was inhabited by older generations before us. We have replaced them.
• But during their life time, they have created hazardous impact on the earth. The industrialization, the quest for more and more natural resources, wars fought, the construction activities such as dams, roads and bridges, extensive deforestation, etc. were their thoughtless activities.
• All these activities were for development of mankind. But most of them have destroyed the delicate balance between the producers and different levels of consumers.
• Due to ever increasing population of human beings there is shortage of food, clothing and shelter. To procure these basic needs, we have exploited many natural resources causing destruction of the earth’s natural ecosystem.
• Now it is our turn to protect the earth as on the same planet the next generations have to survive. We have to hand over the ecosystems of the earth which are in perfect balance to the new generations.
• The future generations need a good quality of air, water and land along with all other living organisms.
• Due to problems like climate change, global warming, pollution, droughts, etc. the environment is impacted, thus in order to keep sustainability of earth, we have to remember that the earth has not been obtained only as ancestral property but we have to save it for future generations.

Question 3.
Write short notes.
a. Environmental conservation.
Answer:
Due to natural and man-made causes, there are many environmental problems on the earth. These problems affect the existence of various living organisms. In order to save these organisms and maintain the environmental balance, there is need for environmental conservation. If this is not done then there will not be any quality of life for the resident humans. For environmental conservation, the Government has formulated acts and rules. UN has established UNEP for the conservation programs.

The people’s participation in the conservation movement is essential. From school age, the environmental values are inculcated in the young minds. Conservation of environment is the social responsibility of everyone. Judicial use of natural resources conservation also way of environmental conservation.

b. Chipko Movement of Bishnoi.
Answer:
Chipko Movement of Bishnoi or Bishnoi Andolan:
Khejarli or Khejadli is a village in Rajasthan, where Bishnoi community is located. The name of the town is derived from Khejri trees.

The first event of Chipko Movement took place in Khejadli village in 1730 AD. In this village 363 Bishnois, led by Amrita Devi sacrificed their lives for protecting the trees of Khejri trees, which trees are considered as sacred by Bishnoi.

Amrita Devi said, “if a tree is saved even at the cost of one’s head, it’s worth it”. She was killed with the axes that were brought to chop off the trees. The three young daughters Asu, Ratna and Bhagubai also sacrificed their lives for trees.

83 Bishnoi villages came together and villagers sacrificed their lives after hearing about Amrita Devi’s sacrifice. Three hundred and sixty-three Bishnois were killed as they opposed the king. After realizing the mistake, the king ordered stoppage of the felling of trees. Honouring the courage of the Bishnoi community, the ruler of Jodhpur, Maharaja Abhay Singh, apologized. He issued a royal decree to protect trees and wild life.

Chipko movement of 20th century in Uttar Pradesh also followed the same pattern of embracing the trees and saving them from cutting.

c. Biodiversity.
Answer:
Biodiversity means the diverse life forms that inhabit any area. Biodiversity is seen due to variety of life forms and different ecosystems that lodge these organisms. In nature there is biodiversity on the three different levels, viz. genetic diversity, species diversity and ecosystem diversity. This means that there is diversity in the individuals belonging to the same specips due to genetic reasons, there is diversity among the different species of organisms and there is also a diversity in the ecosystems that are present in any region.

Due to development of mankind, the biodiversity is threatened. There are special efforts taken to restore the lost and threatened biodiversity. Some of these are establishing sanctuaries, National Parks, biodiversity hotspots and reserves etc. Certain endangered species are protected by carrying out conservation projects.

d. Sacred Groves.
Answer:
Sacred grove is the green patch of the forest which is conserved by local people in the name of God. It does not belong to forest department. It is like a sanctuary that is conserved by the common people and tribals in the area. It is rich in the biodiversity.

It is conserved as there is a faith that God or deity reside in the sacred grove. Hence in local language, they are known as Deorai. Due to this reason, people do not fell the trees. Also hunting of any wild life is not done here. More than 13000 sacred groves have been reported in India. Most of these are in Western Ghats in Maharashtra, Karnataka and Kerala. Also, in remaining parts of India sacred groves are reported. Role of sacred grove is tremendous in conserving the biodiversity.

e. Disaster and its management.
Answer:

• To save human life from disasters. To help them for moving away from the place of disasters by rapid action.
• To supply essential commodities to the affected people. This helps to reduce the gravity of disaster. People are given grains, water and clothes and other basic necessities under this objective.
• To bring back the conditions of affected people to normalcy.
• To rehabilitate the affected and displaced victims.
• To think and execute the protective measures in order to develop capability to face the disasters in
  future.

Question 4.
How will you justify that overcoming the pollution is a powerful way of environmental management?
(OR)
“Solving the problem of pollution is an effective way of environmental management.” Justify the statement.
Answer:
1. Pollution is created only due to human activities. Air, water, soil, noise, radiation, thermal, light, plastic are different types of pollution.
2. All types of pollution affect environment and particularly threatening the survival of living organisms.
3. Pollution must be controlled in order to have good quality of the environment. E.g. When plastic is thrown anywhere, it causes pollution of the land, it clogs the rain water drains, it affects feeding of the animals. Plastic pollution can be completely stopped by us through proper management of plastic waste. By recycling or reusing, we can overcome the plastic pollution. This would be a powerful way of environmental management.
4. Similarly, when we reduce pollution of different types, we automatically help to regain the environmental health.

Question 5.
Which projects will you run in relation to environmental conservatioh? How?
(OR)
Write six strategies implemented by you for conservation of the environment.
Answer:
Initially, assessment of the environmental problems will be done. The nature and severity of these problems will be understood by detailed study of the same. Then the projects can be undertaken to combat these problems.

1. Tree plantation is one such easier project that can be undertaken to conserve environment. The further nurturing of the tree will also be our responsibility. While selecting the tree, the local and sturdy varieties will be selected. Such trees can survive in polluted environment too and even under the pressure of urbanization.

2. Solid waste management is another very important project that should be undertaken by every society, colony or school. Segregation of waste into dry and wet types and then its proper disposal will be taught to all the people in the neighbouring area.

3. To ban the plastic and make people aware about harmful effects of plastic is another very significant project.

4. Fossil fuels are non-renewable and polluting. Therefore, their use should be reduced as far as possible. Therefore, using bicycle, or walking down for shorter distances or using public transport systems are the better alternatives. The awareness drive about these facts will be taken up as a project.

5. To take care of stray animals, provide shelter, feeding endangered birds like sparrows and allowing them to survive with our support is also one of the essential act to conserve other species.

6. Attempts will be made for bringing awareness among minds of everyone. Such small acts can bring about major shift in the attitude of the people. This will certainly help in the environmental conservation.

Question 6.
Answer the following:
a. Write the factors affecting environment.
Answer:

• The biotic and abiotic- factors affect the environment. Among abiotic factors, the physical and chemical factors can alter the conditions of the environment.
• Abiotic factors are either natural or man-made.
• The various interrelationships between different living organisms can also affect environment.
• The natural disasters such as earthquake, forest fires, cyclones, cloud bursting, drought, etc. change the environment.
• The human activities such as deforestation, urbanisation, constructions etc. cause permanent damage to the ecosystems. Due to man-made impact, there can be large scale changes in the environment.

b. Human beings have important place in environment.
Answer:

• Man came last on the earth during evolution of animals. But due to his intelligence, imagination, critical thinking and memory, he made progress in all fields.
• By virtue of these qualities he became the supreme.
• All the natural resources on the earth were very rapidly exploited by man.
• Under the pretext of technology and. development he made degradation of almost all¬natural ecosystems.
• He never obeys the rules of nature.
• Phenomena like pollution, urbanization, industrialization and deforestation are exclusively his creations.
• Hunting and poaching other animals were his contribution to the extinction of many other animals.
• Except man no other organism on the earth can change the ecosystems in such a drastic way. Therefore, it is rightly said that human beings have important place in environment.

c. Write the types and examples of biodiversity.
Answer:
Biodiversity is documented on the following three levels, viz. genetic diversity, species diversity and ecosystem diversity.
1. Genetic Diversity: Diversity seen among the organisms of same species due to genetic differences is called genetic diversity. E.g. The individual human beings are different from each other. No two animals or plants are exactly alike.

2. Species Diversity: The difference between the different species is the species diversity, e.g. All the species of plants, animals and microbes which are seen in any natural environment.

3. Ecosystem Diversity: In one region there may be different ecosystems, such diversity in the ecosystems is called ecosystem diversity. Ecosystems are natural or artificial. Every region shows different types of ecosystems such as aquatic, terrestrial, desert or forest ecosystems. Each ecosystem has its own habitats with resident flora and fauna.

d. How the biodiversity can be conserved?
Answer:
Biodiversity can be conserved by the following ways:

• Protection of the rare species of plants and animals.
• Creating habitats for the animals and plants by establishing National Parkland Sanctuaries.
• Declaration of bioreserves, the areas which are protected through conservation.
• Conservation projects for protecting special species.
• Conservation of all flora and fauna.
• Strict observance of the acts and rules.
• Use of traditional knowledge and maintaining record of traditional knowledge.

e. What do we learn from the story of Jadav Molai Payeng? (Board’s Model Activity Sheet)
Answer:
Jadav Molai Payeng is a common man who was just a simple forest worker. But he has conscience about plants and tree plantations. He single-handedly planted thousands of trees. He converted a barren patch of land into forest which is spread over 1360 acres. For these plantations he continuously worked.

He has shown that a single determined person, can establish a new forest! We understand the values of
hard work, sincerity and devotion to the nature through the story of Jadav Molai Payeng. Even a common man can contribute a lot for the conservation and protection of the environment by learning the story of Payeng.

f. Write the names of biodiversity hot spots.
Answer:

• In entire world, 34 highly sensitive biodiversity spots are reported.
• These hotspots occupied 15.7% area of the Earth.
• However, currently about 86% of the sensitive areas are already destroyed.
• Now about 2.3% area of the Earth still has such sensitive biodiversity spots.
• There are 1,50,000 plant species which are about 50% of the species in the world.
• In India, out of 135 species of animals, 85 species are found in the jungles of eastern region.
• There are about 1,500 endemic plant species in Western Ghats.
• About 50,000 plants species out of the total plants in the world are said to be endemic.

g. Which are the reasons for endangering the many species of plants and animals? How can we save those diversity?
Answer:

• The animals and plants species are endangered majorly due to man-made causes.
• Some natural disasters like earthquakes, climate change, forest fires, drought and cyclones also affect the living organisms due to lack of food and water.
• In man-made causes, hunting and poaching are the main reasons.
• Also animal-human conflicts occur due to invasion of human settlements into the habitats of wild animals.
• Construction of dams, roads, and colonies destroy the habitats of wild life.
• Industrialization, urbanization and population explosion of humans are putting severe pressure on all the existing biodiversity.
• In order to save and protect the biodiversity, many scientists and naturalists come together. A stretch of land is protected by declaring it as the sanctuary or a national park by the Government. Even the locals can protect it as a sacred grove.
• Various acts and rules have been formulated to protect the organisms. The violators of such rules are punished accordingly.

Question 7.
What are the meanings of the following symbols? Write your role accordingly. (July ’19; Board’s Model Activity Sheet)
(OR)
What do these symbols indicate? Explain your opinion about those symbols.

Answer:
1. The first symbol is for giving the message, “Reduce, reuse and recycle”. This is important mantra for the utilization of natural resources.
The second symbol gives the message about ‘Save water’.
The third symbol advocates the use of solar energy.

2. These symbols inculcate the importance of being eco-friendly. The first symbol is essential to maintain the natural resources by reusing and recycling them. As far as possible, one should reduce the excessive use of resources by preventing consumerism.

3. Water problems persist in many major cities and villages. In villages it results in drought like conditions. It also reflects into loss of agricultural produce. Therefore, the message about saving water or to make judicious use of water should be spread far and wide.

4. The solar energy is the renewable energy option which is very easily available in country like India. By using solar energy, we can replace the polluting and exhaustible fuels. Thereby, pollution will also be reduced.

Due to such symbols, important messages about environment conservation reach, us and we can change ourselves into more eeofriendly persons.

Project: (Do it your self)

Project 1.
Make a presentation on pollution of Gangci and Yamuna Rivers and effects of air pollution on Taimuhal.

Can you recall? (Text Book Page No. 36)

Question 1.
What is ecosystem? Which are its different components?
Answer:
In any environment, there are biotic and abiotic components. There are interactions among these components. All such interactions make an ecosystem.

The different components in the ecosystem are as follows:
Abiotic components : Air, water, soil, sunlight, temperature, humidity, etc.
Biotic components: All the types of living organisms, like bacteria, fungi, plants and animals.

Question 2.
Which are the types of consumers? What are the criteria for their classification?
Answer:
Primary consumers, secondary consumers, tertiary consumers or apex consumers are the different types of consumers. These types are according to the trophic level to which they belong.

Question 3.
What may be the relationship between lake and birds on tree?
Answer:
The birds on the tree depend on the aquatic organisms in the lake for their feeding. Birds stay on the trees which are in the vicinity of the lake, so that it is easier for them to capture fishes, frogs, etc. They must also be using the same lake water for drinking.

Question 4.
What is difference between food chain and food web?
Answer:
In every ecosystem, there are always interactions between producers, consumers and decomposers. This sequence of feeding interactions is called food chain. In every food chain there are links between four to five trophic levels constituting the producers, primary consumers, secondary consumers, tertiary consumers, etc. The links of food chain are in linear sequence. But food web is a complex network of many small food chains. In fact, food web is the collection of many small food chains. Thus, when many food chains are interwoven, they form food web.

Think and Answer! (Text Book Page No. 36)

Question 1.
Write the name and category of each of the component shown in picture.
Answer:
By utilizing the solar energy, the green plants perform photosynthesis. Thus, they are producers of the food chain. This food is consumed by the grasshopper. Thus, it is primary consumer. Frog is secondary consumer as its diet consists of insects like grasshopper. Snake is tertiary consumer as it feeds on frogs, while the hawk is apex consumer as it can kill the snake and feed on it. Last picture in the food chain is of fungi which are acting as decomposers. Few bacteria are shown in the picture, act on all the levels and bring about decomposition.

Question 2.
What is necessary to convert this picture into food web? Why?
Answer:
If this food chain has to be converted into a food web, there should be interactions between the different components. Any living organism can be prey to different predators. Moreover, a predator can also be a prey for other. Frog eats different insects. The same frog can be either eaten by snake or by hawk.

Use your brain power. (Text Book Page No. 40)

Question 1.
Why is it said that pollution control is important?
Answer:
The quantity of pollutants and severity of their effects on the ecosystem have to be taken into consideration constantly. The different methods of pollution control have to be used for checking the hazardous effects of pollution on the living organisms. Especially the impact of pollution on health of human beings is assessed from time to time.

The young children and senior citizens are affected to greater extent by the pollution. If the air and water required for the survival of the people is affected, then exercising the pollution control is to be done immediately. Thus, it is said that pollution control is important.

Enlist and discuss (Text Book Page No. 43)

Question 1.
Find the meaning of given symbols in relation to environment conservation. Make a list of other such symbols.
A.
Answer:
This symbol tells us to keep our wastes carefully. The garbage should not be strewn anywhere. But it should be properly managed. Waste if managed properly can be a wealth.
B.
Answer:
This symbol tells us to save electricity. If electricity is carefully used, we can save our natural resources. This message is given through this picture.
C.
Answer:
Use of bicycle means use of green energy. By riding on a bicycle we save on fuel and use our own muscular energy. It is the best eeofriendly, non polluting vehicle.

Observe and fill the information: (Text Book Page No. 8)

Question 1.
Observe the environment around you. Complete the following flow chart.

Answer:

Complete the Chart: (Text Book Page No. 39)

Question 1.
We have studied the air pollution, water pollution and soil pollution in detail in earlier classes. Based on that, complete the following chart.

Answer:

Complete the Chart: (Text Book Page No. 40)

Question 1.
Now a day, we are observing the environmental degradation everywhere. Complete the flow chart given besides with the help of environment.

Answer:

(Text Book Page No. 43)

Question 1.
Where are such sacred groves in Maharashtra? Make a list and visit with your teachers.
Answer:
Sacred groves: Sacred groves form an important landscape feature in the deforested hill ranges of the Western Ghats. The felling of timber and the killing of animals in sacred groves is not allowed by the locals. It is considered as taboo.

In Maharashtra, sacred groves are found in tribal as well as non-tribal areas. The sacred groves in the western part are called Devrai or Devrahati, which means the abode of the gods. In eastern parts it is called Devegudi by the madiya tribal people.

In Maharashtra 2820 Devrais have been documented. Maruti, Vaghoba, Vira, Bhiroba, Khandoba and Shirkai are some deities to which sacred groves are dedicated.

In the sacred groves, the most commonly found plant species are Portia tree, Casuarina, Silk cotton tree, Indian laurel, Indian Elm, Bead tree, Indian butter tree, Turmeric and Japanese ginger. In Maharashtra, sacred groves are maximum in district of Sindhudurg, (More than 1500 out of total 2820) followed by Ratnagiri, then Pune and in district of Satara.

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

Question 1.
Paddy fields are frequently attacked by
(a) goats
(b) birds
(c) grasshoppers
(d) monkeys
Answer:
(c) grasshoppers

Question 2.
Basic functional unit to study the ecology is termed as ……………
(a) environment
(b) niche
(c) ecosystem
(d) food chain
Answer:
(c) ecosystem

Question 3.
As per ……….. trading of rare animals has been completely banned.
(a) clause 48A
(b) clause 49B
(c) clause 49A
(d) all the above
Answer:
(c) clause 49A

Question 4.
(4) The jungle in Kokilamukh of Jorhat district of Assam is well known as ………….
(a) Molai jungle
(b) Rhino jungle
(c) Rhino forest
(d) Payang jungle
Answer:
(a) Molai jungle

Question 5.
Maintaining record of ………. knowledge is very necessary.
(a) modern
(b) mythical
(c) vedic
(d) traditional
Answer:
(d) traditional

Question 6.
………… is world’s largest organization engaged in environmental activities.
(a) Greenpeace
(b) Hariyali
(c) B. N. H. S.
(d) I. I. T.
Answer:
(a) Greenpeace

Question 7.
……….. sanctuary of West Bengal is reserved for tigers.
(a) Gir
(b) Sunderban
(c) Molai
(d) Corbett
Answer:
(b) Sunderban

Question 8.
World Biodiversity Day is celebrated on ……… every year.
(a) 22nd April
(b) 5th June
(c) 16th September
(d) 22nd May
Answer:
(d) 22nd May

Question 9.
Out of the total plant species in the entire world, 50,000 are ……………
(a) extinct
(b) endangered
(c) endemic
(d) rare
Answer:
(c) endemic

Question 10.
Giant squirrel is an ………… species.
(a) indeterminate
(b) rare
(c) endemic
(d) endangered
Answer:
(a) indeterminate

Question 11.
In a food chain, autotrophic plants are present at the ……….. level. (March 2019)
(a) tertiary nutrition
(b) secondary nutrition
(c) producer
(d) apex
Answer:
(c) producer

Question 12.
……….. from Manas sanctuary in Assam is under threat. (Board’s Model Activity Sheet)
(a) one horned rhino
(b) Lion
(c) Musk deer
(d) Giant squirrel/Shekru
Answer:
(a) one horned rhino

Write whether the following statements are true or false, giving suitable explanation for the same:

Question 1.
Only abiotic factors play very important role in the ecosystem.
Answer:
False. (Both abiotic and biotic factors play very important role in the ecosystem. Only abiotic factors will not decide the working of an ecosystem.)

Question 2.
Paddy fields are frequently attacked by frogs.
Answer:
False. (Paddy fields are frequently attacked by grasshoppers. Frogs feed on grasshoppers and control the population of these insects that cause destruction of the crops.)

Question 3.
Environmental pollution is necessary and acceptable change in the surrounding environment.
Answer:
False. (Environmental pollution is never acceptable. It is always harmful to the entire ecosystem and thus never necessary.)

Question 4.
X-rays and radiations from atomic energy plants are natural radiations.
Answer:
False. (X-rays are not present in natural radiations. Infra-red and ultra-violet rays are present in natural radiations.)

Question 5.
The person breaching the Environmental Conservation Act is entitled for either one year imprisonment or fine up to ₹ 5 lakh.
Answer:
False. (The person breaching the Environmental conservation Act is fined upto ₹ 1 lakh. He is also entitled to imprisonment for five years.)

Question 6.
Many people come together to establish arnew forest but a single person, if determined can destroy the entire forest!
Answer:
False. (When anything constructive has to be done even a single man can start such action. In case of ‘Molai jungle’, this statement holds true. But when destructive actions are done, many people come together and cause damage.)

Question 7.
There are clusters of thick forests only in Western Ghats of India.
Answer:
False. (Entire India is rich in biodiversity. Just not in Western Ghats but in entire India one can observe the clusters of thick forests and this is mainly due to suitable tropical climate.)

Question 8.
86 highly sensitive biodiversity spots are reported all over the world.
Answer:
False. (As per the latest information and available data, there are 34 highly sensitive biodiversity spots.)

Question 9.
Flow of nutrients in an ecosystem is unidirectional.
Answer:
False. (Flow of energy in an ecosystem is unidirectional. Flow of nutrients is cyclic.)

Match the columns:

Question 1.

Column I	Column II
(1) Physical, chemical and biological factors together form	(a) Biodiversity
(2) The science of interactions between biotic and abiotic factors	(b) Ecosystem
	(c) Ecology
	(d) Environment

Answer:
(1) Physical, chemical and biological factors together form – Environment.
(2) The science of interactions between biotic and abiotic factors – Ecology.

Question 2.

Column I	Column II
(1) Basic functional unit in the environment	(a) Biodiversity
(2) Different types of living organisms	(b) Ecosystem
	(c) Ecology
	(d) Environment

Answer:
(1) Basic functional unit in the environment – Ecosystem.
(2) Different types of living organisms – Biodiversity.

Question 3.

Rules/Act	Year
(1) Sound Pollution (Control and Prevention) Rule	(a) 1980
(2) Biomedical Waste (Management and Handling) Rule	(b) 2011
	(c) 1998
	(d) 2000

Answer:
(1) Sound Pollution (Control and Prevention) Rule – 2000.
(2) Biomedical Waste (Management and Handling) Rule – 1998.

Question 4.

Rules/Act	Year
(1) Forest Conservation Act	(a) 1980
(2) Environmental Conservation Act	(b) 1986
	(c) 2011
	(d) 2000

Answer:
(1) Forest Conservation Act – 1980.
(2) Environmental Conservation Act – 1986.

Question 5.

Species	Examples
(1) Endangered	(a) Red panda, Musk deer.
(2) Rare	(b) Tiger, Lion.
	(c) Lion tailed monkey, lesser florican.
	(d) Monkey, squirrel

Answer:
(1) Endangered Species – Lion tailed monkey, lesser florican.
(2) Rare Species – Red panda, Musk deer.

Question 6.

Species	Examples
(1) Vulnerable	(a) Giant squirrel (Shekhru)
(2) Indeterminate	(b) Red panda, Musk deer
	(c) Tiger, Lion
	(d) Lesser florican, sparrow

Answer:
(1) Vulnerable Species – Tiger, Lion.
(2) Indeterminate Species – Giant squirrel (Shekhru).

Find the odd one out:

Question 1.
Ash, Carbon dioxide, Lead, Asbestos
Answer:
Carbon dioxide. (All others are solid particulate pollutants.)

Question 2.
Manas sanctuary, Sunderbans sanctuary, The Western Ghats, Tadoba National Park
Answer:
Tadoba National Park. (All others are endangered heritage places of India.)

Question 3.
Lion tailed monkey, White rats, Musk deer, Tiger
Answer:
White rats. (All others are species that are threatened.)

Question 4.
Conservation, Regulation, Pollution, Prohibition
Answer:
Pollution. (All others are ways of environmental protection.)

Question 5.
IPCC, UNEP, IUCN, BNHS
Answer:
BNHS. (All others are international organizations. BNHS is Bombay Natural History Society.)

Find the correlation:

Question 1.
Rare species : Musk deer : : ………… : Lesser florican.
Answer:
Endangered species

Question 2.
Red panda : Rare species : : Giant Squirrel : …………
Answer:
Indeterminate species

Question 3.
Nitrogen, Oxygen : Gaseous cycle : : Soil and Rocks : …………
Answer:
Sedimentary cycle

Question 4.
Manas : One horned Rhino : : Gir : ………..
Answer:
Asiatic lion

Question 5.
Mumbai : Bombay Natural History Society : : TehriGarhwal : ………….
Answer:
Chipko centre.

Answer the following questions in detail:

Question 1.
Answer the following questions:
If frog population in paddy field declines all of a sudden,
(a) What will be the effect on paddy crop?
Answer:
If the population of frog declines, then there will be rise in the population of grasshoppers. The paddy fields will hence be infested with insect pests.

(b) Number of which consumers will decline and which will increase?
Answer:
The food chain if altered, results in imbalance in the ecosystem. ‘Paddy → Grasshoppers → Frog → Snake’, this food chain is natural. When by any reason there is dec1ine in the number of frogs, thus secondary consumer will also decline. Due to this decline, snake which is at tertiary consumer level will also decline. Theprimary consumers i.e. grasshoppers will increase as there is now no check on their population. Due to increase in their population the paddy production will be reduced. Due to reduced number of snakes, rats and other rodents from neighbouring areas would also rise, which are also secondary consumers.

(c) Name the Indian states where paddy is cultivated on a large scale.
Answer:
West Bengal, Uttar Pradesh, Haryana, Punjab, Tamil Nadu, Andhra Pradesh, Bihar, Chhattisgarh, Odisha, Assam and Maharashtra.

Question 2.
What is radioactive pollution? What are its effects?
Answer:
(1) The radiations emitted either through the natural sources or through man-made sources cause radioactive pollution.
(2) The natural radiations is in the form of ultra violet and infrared radiations.
(3) Artificial or man-made radiations are X-rays and radiations from atomic energy plants.
(4) All radiations are highly hazardous for the living organisms. The impact of radiation is also for a very long time.
(5) It has brought about major accidental mishaps at Chernobyl, Windscale, qpd Three Miles Island. These disasters have affected thousands of people.
(6) Some other effects of radiations are as follows – (i) Due to higher radiations of X-rays, cancerous ulceration occurs, (ii) Radiations destroy the body tissues, (iii) Radiations cause mutations and thus genetic changes occur, (iv) There is adverse effect on the vision.

Question 3.
Give one word for “The forest conserved in the name of God.” (Board’s Model Activity Sheet)
Answer:
Deorai.

Give scientific reasons:

Question 1.
Certain scavenging caterpillars, termites and insects found in the dung are important.
Answer:

• Scavenging caterpillars and insects are decomposers. They seem to be Worthless due to filthy surrounding in which they thrive.
• But they carry out most important task of decomposition of complex organic substances into simple inorganic elements.
• This recycling is possible only due to decomposers.
• If they are not present, there will be huge accumulation of garbage. Therefore, these living organisms are important.

Question 2.
Destroying trees is to destroy everything.
Answer:

• When a single huge tree is felled many living organisms which are dependent on it, are exterminated.
• Many insects, fungi, birds, etc. lose their habitat.
• Trees take up carbon dioxide from the atmosphere and release oxygen. These natural cycles are also hindered due to loss of trees.
• Due to trees there is shade, cooler atmosphere and increase in the rainfall. When such trees are destroyed all the components in the ecosystem are destroyed too.

Question 3.
There is no definite information about indeterminate species.
Answer:

• Indeterminate species do not have substantial information about them.
• The organisms belonging to such species appear to be endangered due to their some behavioural habits.
• They are shy and do not come in open so that they can be observed keenly.
• For example, animals like Giant squirrel also do not provide such information.

Question 4.
Tigers from Sunderbans and Rhinos from Manas are under threat.
Answer:

• Manas is in the area-of Assam where there are many dams and Indiscriminate use of water.
• This area is also flood affected. Therefore, rhinos are under threat.
• In Sunderbans, there are also problems such as deforestation, dams, excessive fishing, and dug out trenches.
• All of these cause dangers to the tiger population.

Question 5.
There are clusters of thick forests in the Western Ghats of India.
Answer:

• There are many sacred groves in the region of Western Ghats of India.
• These forests are not conserved by Government Forest Departments but are cared for by the local people, in the name of God.
• Due to such faith in the people, the forests are conserved like sanctuaries.
• Such many clusters are in Western Ghats of Maharashtra.

Question 6.
We can see biodiversity on three levels.
Answer:

1. There is biodiversity in the living organisms belonging to the same genus.
2. This diversity is due to different heredity pattern. This is called genetic biodiversity.
3. The organisms occupying the same area and belonging to the same species also show diversity due to different species. This is species biodiversity.
4. The organisms occupying different ecosystems also show differences, which is called ecosystem biodiversity. Therefore, we observe biodiversity on three different levels.

Questions based on diagrams:

Question 1.
What is shown in the picture? Write name and trophic level of each component.

Answer:
In this picture, food chain having rive trophic levels is shown.
(1) Trophic level 1 = Producers : Green plant.
(2) Trophic level 2 = Primary consumer (Herbivore): Grasshopper.
(3) Trophic level 3 = Secondary consumer (Carnivore): Bird.
(4) Trophic level 4 = Tertiary consumer (Carnivore) : Snake.
(5) Trophic level 5 = Top or Apex consumer (Carnivore) : Owl.

Question 2.
Explain the meaning of following symbols A and B and C.
A.

Answer:
The symbol show types of green energy such as solar energy and wind energy. It also expresses that people
should use such sources of energy for their use.

B.

Answer:
This symbol is giving the message “Save water”. Sustainable use of water is necessary for our future.

C.

answer:
The symbols of WWF and BNHS are shown here. BNHS stands for Bombay Natural History Society. This institute works for the conservation and documentation of flora and fauna.

WWF means World Wild Life Fund. Also known as World Wide Life Fund. This International Institute is looking after the welfare of wildlife through different conservation projects. WWF symbol shows Panda while BNHS symbol has Giant Hornbill.

Question 3.
(a) Identify the following symbols and state their significance: (March 2019)

Answer:
(i) This symbol is giving the message “Save water”. Sustainable use of water is necessary for our future.
(ii) Use of bicycle means use of green energy. By riding on a bicycle we save on fuel and use our own muscular energy. It is the best ecofriendly, non polluting vehicle.

(b) How can biodiversity be conserved?
Answer:
Biodiversity can be conserved by the following ways:

• Protection of the rare species of plants and animals.
• Creating habitats for the animals and plants by establishing National Park and Sanctuaries.
• Declaration of bio reserves, the areas which are protected through conservation.
• Conservation projects for protecting special species.
• Conservation of all flora and fauna.
• Strict observance of the acts and rules.
• Use of traditional knowledge and maintaining record of traditional knowledge.

Activity based questions:

Question 1.
Questions based on the charts.
Complete the flow chart: (July 2019)

Answer:

Question 2.
Collect more information about locations of these hotspots present in the world. (Textbook page no. 44)
Answer:
Students should collect this information.

Question 3.
Where are such sacred groves in Maharashtra? Make a list and visit with your teachers. (Textbook page no. 43)
Answer:
Sacred groves: Sacred groves form an important landscape feature in the deforested hill ranges of the Western Ghats. The felling of timber and the killing of animals in sacred groves is not allowed by the locals. It is considered as taboo.

In Maharashtra, sacred groves are found in tribal as well as non-tribal areas. The sacred groves in the western part are called Devrai or Devrahati, which means the abode of the gods. In eastern parts it is called Devegudi by the madiya tribal people.

In Maharashtra 2820 Devrais have been documented. Maruti, Vaghoba, Vira, Bhiroba, Khandoba and Shirkai are some deities to which sacred groves are dedicated.

In the sacred groves, the most commonly found plant species are Portia tree, Casuarina, Silk cotton tree, Indian laurel, Indian Elm, Bead tree, Indian butter tree, Turmeric and Japanese ginger. In Maharashtra, sacred groves are maximum in district of Sindhudurg, (More than 1500 out of total 2820) followed by Ratnagiri, then Pune and in district of Satara.

Projects: (Do it your self)

Project 1.
Let’s Discuss: (Text Book Page No. 41)
Collect the information about Chipko Movement and discuss between two groups of your class about its importance in present situation.

Project 2.
Collect more information on the organization of Greenpeace. (Text Book Page No. 43)
Answer:
Students are expected to write this answer to this question.

Project 3.
There should be positive attitude of human being towards the environment for welfare of entire living world. For this purpose, following roles are important. You can be a conservator, organizer, guide, plant-friend, etc. Describe about the role you wish to perform and your plans for that role. (Text Book Page No. 42)

Project 4.
Survey the plants and animals in your area. Maintain a record about their characteristics. (Text Book Page No. 45)
Answer:
Students can conduct such surveys with the help of elders.

Project 5.
Internet is my friend! (Collect the information Textbook page no. 41)
(1) Sound Pollution (Control and Prevention) Rule, 2000.
(2) Biomedical Waste (Management and Handling) Rule, 1998.
(3) E-waste (Management and Handling) Rule, 2011.

Balbharti Maharashtra State Board Class 10 Science Solutions Part 2 Chapter 6 Animal Classification Notes, Textbook Exercise Important Questions and Answers.

Maharashtra State Board Class 10 Science Solutions Part 2 Chapter 6 Animal Classification

Question 1.
a. I am diploblastic and acoelomate. Which phylum do I belong to ?
Answer:
I am from phylum Cnidaria or Coelenterata.

b. My body is radially symmetrical. Water vascular system is present in my body. I am referred as fish though I am not. What is my name?
Answer:
Starfish. I am from Echinodermata phylum.

c. I live in your small intestine. Pseudocoelom is present in my thread like body. In which phylum will you include me?
Answer:
I am Ascaris. I am included in Aschelminthes.

d. Though I am multicellular, there are no tissues in my body. What is the name of my phylum?
Answer:
Sponge, Porifera.

Question 2.
Write the characters of each of the following animals with the help of classification chart:
a. Bath sponge.
Answer:
Classification:
Kingdom: Animalia
Sub-kingdom: Non-chordata
Phylum: Porifera
Characters:

• Multicellular organisms without cell wall
• Cellular grade organization.
• Asymmetrical body
• Acoelomate

Bath sponge is a marine animal. Blackish in colour and round in shape having porous body. It has spongin fibres and spicules which serve as skeleton. Bath sponges have good water-holding capacity. It is sedentary animal which is fixed to some substratum in the aquatic environment. Reproduction is by budding. It also has a good regeneration capacity.

b. Grasshopper.
Answer:
Classification:
Kingdom: Animalia
Sub-kingdom: Non-chordata
Phylum: Arthropoda
Class: Insecta
Characters:

• Multicellular organisms without cell wall
• Organ-system grade organization
• Bilaterally symmetrical
• Triploblastic and Eucoelomate.

Grasshopper is an insect included under class insecta of phylum arthropoda because it has jointed appendages. There are three pairs of legs and two pairs of wings. It is a terrestrial insect which is well adapted to the surrounding environment by showing camouflage. It has chitinous exoskeleton. The respiration by tracheae.

c. Rohu.
Answer:
Classification:
Kingdom: Animalia
Phylum: Chordata
Class: Pisces
Subclass: Teleostei (Bony fish)
Characters:

• Multicellular organisms without cell wall
• Organ-system grade organization
• Bilaterally symmetrical
• Triploblastic and Eucoelomate.

Rohu is a fresh water bony fish. It is a chordate having a vertebral column, hence included under subphylum vertebrata. The body is well adapted for aquatic mode of life. The shape of the body is streamlined. The exoskeleton is of scales. The gills Eire present which are used for respiration. The endoskeleton is of bones, hence called bony fish. There are paired fins and a impaired caudal fin which is used in steering and changing the direction during swimming.

d. Penguin.
Answer:
Classification:
Kingdom: Animalia
Phylum: Chordata
Class: Aves
Characters:

• Multicellular organisms without cell wall
• Organ-system grade organization
• Bilaterally symmetrical
• Triploblastic and Eucoelomate.

Penguin is a flightless bird inhabitant of cold snow-clad regions. It has exoskeleton of feathers. The body is well adapted to survive in cold regions.

It is a warm-blooded bird. The forelimbs are modified into wings. But due. to excessive body weight, the penguins are not seen flying. It can wade in the water with modified hind limbs.

e. Frog.
Answer:
Classification:
Kingdom: Animalia
Phylum: Chordata
Class: Amphibia
Characters:

• Multicellular organisms without cell wall
• Organ-system grade organization
• Bilaterally symmetrical
• Triploblastic and Eucoelomate.

The frog is a true amphibian that can live in water as well as on land. When on land it respires with the help of lungs while in water it uses its skin for breathing. It does not have exoskeleton. The skin is soft, slimy and moist. It is suitably coloured and hence the frog can camouflage in the surroundings. Body is divisible into head and trunk. Two pairs of limbs are seen. The forelimbs are short and used for support during locomotion. The hind limbs are long and strong, used for jumping when on land and for swimming when in water.

The eyes are large and protruding. Since the neck is absent, such eyes help in looking around. The tympanum is present.

f. Lizard.
Answer:
Classification:
Kingdom: Animalia
Phylum: Chordata
Class: Reptilia
Characters:

• Multicellular organisms without cell wall
• Organ-system grade organization
• Bilaterally symmetrical
• Triploblastic and Eucoelomate.

The lizard is a cold-blooded reptile. The limbs are weak and do not support the body weight, hence lizard is seen creeping. But the feet are provided with pads and suckers due to which lizards are well- adapted to climb on the vertical walls. The exoskeleton has fine scales. The body is divisible into head, neck and trunk. The capacity to regenerate is developed in lizards, hence it can produce the lost tail or limbs. The mode of reproduction is egg laying. It feeds on insects with the help of long and sticky tongue.

g. Elephant.
f. Lizard.
Answer:
Classification:
Kingdom: Animalia
Phylum: Chordata
Class: Mammalia
Characters:

• Multicellular organisms without cell wall
• Organ-system grade organization
• Bilaterally symmetrical
• Triploblastic and Eucoelomate.

Elephant is the terrestrial, herbivorous mammal adapted to survive in hot and humid tropical forests.
It is a mammal and hence shows viviparity and milk secretion. The body is divisible into head, neck, trunk, and tail. The proboscis is a characteristic feature of the elephant which is actually modified nose.

h. Jellyfish.
Answer:
Classification:
Kingdom: Animalia
Sub-kingdom: Non-chordata
Phylum: Cnidaria or Coelenterata
Characters:

• Multicellular organisms without cell wall
• Tissue grade organization
• Radially symmetrical
• Diploplastic and Acoelomate

Jellyfish or Aurelia is a coelenterate. Its body is medusa. It appears as a transparent balloon seen floating in the marine waters. Since it has appearance like a jelly, it is known commonly as jellyfish. There are tentacles provided with cnidoblasts or stinging cells. Tentacles are used for catching the prey. Cnidoblasts are used to secrete a toxin which paralyses the prey.

Question 3.
Write in brief about progressive changes in animal classification.
Answer:
There were different methods of classification of animals.

1. The first classification method was given by the Greek philosopher Aristotle. He took into account the criteria like body size, habits and habitats of the animals. This method was called artificial method of classification.
2. The same artificial method was used by other scientists such as Theophrastus, Pliny, John Ray, Linnaeus, etc.
3. Further due to advances in science the references were changed and there were some new methods of classification proposed.
4. The system of classification called ‘Natural system of classification’ was then proposed. This system of classification was based on criteria such as body organization, types of cells, chromosomes, bio-chemical properties, etc.
5. Later, Dobzhansky and Meyer gave the system of classification based on evolution.
6. In 1977, Carl Woese has also proposed the three domain system of animal classification.

Question 4.
What is the exact difference between grades of organization and symmetry? Explain with examples.
Answer:
I. Grades of organization:
(1) The grades of organization mean the way an organism has different body formation.
(2) Unicellular organisms like amoeba have a single cell in the body and hence the organization in its body is called protoplasmic grade of organization.
(3) Some organisms have only cells in their body which is called cellular grade of organization, e.g. Poriferans.
(4) Some have tissues e.g. Coelenterates. They are said to have tissue grade organization. Some have organs, they are said to have organization-organ grade, e.g. Platyhelminthes. All other higher animals have organ-system grade organization.

II. Symmetry:
(1) Symmetry on the other hand shows the base of the body formation.
(2) The symmetry can be understood by taking an imaginary cut through the animal body.
(3) Based on the symmetry there can be three types.
(4) In asymmetric animals, there is no symmetry in any plane, e.g. Amoeba.
(5) The bilateral symmetry is the one in which an imaginary axis can pass through only one median plane to divide the body into two equal halves. Most of the animals have bilateral symmetry and hence their organs are arranged in symmetric way on both the sides.
(6) The imaginary cut passing through the central axis but any plane of body aan -give more than one equal half. The organs of such animals are arranged in a radius of an imaginary circle, e.g. Cnidarians and some echinoderms.
Both grades of organization and symmetry are the bases for classifying animals into different phyla.

Question 5.
Answer in brief.
a. Give scientific classification of shark upto class.
Answer:
Kingdom: Animalia
Phylum: Chordata
Subphylum: Vertebrata
Class: Pisces
Subclass: Elasmobranchii (Cartilaginous)
Example: Scientific name: Scoliodon sorrakowah.
Common name: Shark

b. Write four distinguishing characters of phylum – Echinodermata.
Answer:
Distinguishing characters of Echinodermata:

1. Marine organisms with skeleton made up of calcareous spines. Calcareous material on the body hence the name is Echiodermata. Some are sedentary while some are free swimming.
2. Body is triploblastic, eucoelomate and radially symmetrical when adult. The larvae are bilateral symmetrical.
3. Locomotion with the help of tube-feet which are also used for capturing the prey.
4. Echinoderms have regeneration capability. Hence they can restore their lost parts.
5. Most of them are unisexual.
6. Examples; Starfish, sea-urchin, brittle star, sea cucumber, etc.

c. Distinguish between butterfly and bat with the help of four distinguish properties.
Answer:
Butterfly:

1. Butterfly is classified as Non-chordate.
2. It is included in class Insecta of phylum Arthropoda.
3. Butterfly has three pairs of legs and two pairs of chitinous wings.
4. Butterfly is a diurnal (active during day) insect.
5. Butterfly lays eggs which hatch into larva. Larva develops into pupa and pupa metamorphoses into an adult.

Bat:

1. Bat is classified as a Chordate.
2. It is included in class Mammalia of subphylum Vertebrata.
3. Bat has one pair of legs and a pair of patagium which are used for flying. Patagium has bones.
4. Bat is a nocturnal (active at night) mammal.
5. Bat is a viviparous animal that gives birth to live young ones. Young ones are fed by milk secreted by mammary glands.

d. To which phylum does Cockroach belong? Justify your answer with scientific reasons.
Answer:
(1) Cockroach belongs to the phylum Arthropoda and class Insecta.
(2) Scientific reasons for placement of Cockroach in the phylum Arthropoda:

• The body is covered by chitinous exoskeleton.
• Jointed appendages present, three pairs of walking legs and two pairs of membranous wings.
• Body is eucoelomate, triploblastic, bilaterally segmented and segmented.
• Respiration by spiracles and tracheal tubes.

Question 6.
Give scientific reasons.
a. Though tortoise lives on land as well as in water, it cannot be included in class-Amphibia.
Answer:

• When tortoise lives on the land, it respires with the help of lungs.
• When in water, it puts out its nares (nasal openings) out of the water and breathes air.
• It cannot take up oxygen dissolved in water. In both the habitats it respires with the help of lungs. In case of true amphibians, this is not the case.
• They can breathe in water with the help of skin and on land with the help of lungs.
• Tortoise also has exo-skeleton which is lacking in Amphibia. Therefore, tortoise cannot be included in class Amphibia.

b. Our body irritates if it comes in contact with jellyfish.
Answer:

• Jellyfish is a coelenterate that has cnidoblasts bearing tentacles.
• These cnidoblasts inject toxins to paralyse the prey at the time of feeding.
• When jellyfish comes in contact with our body, this toxin is released causing reaction to our skin.
• Therefore, our body gets irritation when we come in contact with jellyfish.

c. All vertebrates are chordates but all chordates are not vertebrates.
Answer:

• All chordates possess notochord in some period of their development.
• All vertebrates also have notochord during embryonic life, which is later replaced by vertebral column.
• Therefore all vertebrates are chordates.
• But some chrodate’s like Urochordata and cephalochordata do not possess vertebral column and hence they are not vertebrates.

d. Balanoglossus is connecting link between non-chordates and chordates.
Answer:

• Balanoglossus shows some characters of non-chordates.
• It also has notochord as in case of chordates.
• Since it shares the characters of non-chordates and chordates, from the view point of evolution, it is called connecting link between them.

e. Body temperature of reptiles is not constant. (Board’s Model Activity Sheet)
Answer:

1. Reptiles are cold-blooded animals.
2. The thermoregulatory system is not there in their bodies.
3. Their body temperatures, fluctuate as per the environmental temperatures.
4. Therefore, the body temperature is not maintained at constant level in reptiles.

Question 7.
Answer the following questions by choosing correct option.
a. Which special cells are present in the body of sponges (Porifera)?
1. Collar cells
2. Cnidoblasts
3. Germ cells
4. Ectodermal cells
Answer:
1. Collar cells
Explanation: Porifera animals are attached to the substratum. They do not show locomotion. For gathering and catching the food, they need to produce a current in the water. For this purpose, they have characteristic collar cells in their body. Germ cells and ectodermal cells are seen in all other phyla. Cnidoblasts are characteristic feature of coelenterates.

b. Which of the following animals’ body shows bilateral symmetry?
1. Starfish
2. Jellyfish
3. Earthworm
4. Sponge
Answer:
3. Earthworm
Explanation: When an imaginary plane passing through only one axis can divide the body into two equal halves, then it is called bilateral symmetry. Such symmetry is shown only by earthworm. Sponge body is asymmetrical while starfish and jellyfish are radially symmetrical.

c. Which of the following animals can regenerate it’s broken body part?
1. Cockroach
2. Frog
3. Sparrow
4. Starfish
Answer:
4. Starfish
Explanation: Cockroach, sparrow and frog cannot perform regeneration. Only echinoderms show power of regeneration. So only starfish can regenerate its broken part.

d. Bat is included in which class?
1. Amphibia
2. Reptilia
3. Aves
4. Mammalia
Answer:
4. Mammalia
Explanation: Bat gives birth to young ones and they also possess mammary glands. Amphibia, Reptilia and Aves do not show such features. Therefore, bat is included in Mammalia.

Question 8.

Body cavity	Germ Layer	Phylum
Absent	_____________	Porifera
Absent	Triploblastic	_____________
Pseudocoelom	_____________	Aschelminthes
Present	_____________	Arthropoda

Answer:

Body cavity	Germ Layer	Phylum
Absent	Diploblastic	Porifera
Absent	Triploblastic	Platyhelminthes
Pseudocoelom	Triploblastic	Aschelminthes
Present	Triploblastic	Arthropoda

Question 9.

Type	Character	Examples
Cyclostomata	……………	……………
……………	Gill respiration	……………
Amphibia	……………	……………
……………	……………	Whale, Cat, Man
……………	Poikilotherms	……………

Answer:

Type	Character	Examples
Cyclostomata	Jawless mouth with suckers	Petromyzon, Myxine
Pisces	Gill respiration	Pomfret, Sea horse, Shark
Amphibia	Moist skin without exoskeleton	Frog, Toad, Salamander
Mammalia	Mammary glands	Whale, Cat, Man
Reptilia	Poikilotherms	Tortoise, Lizard, Snake

Question 10.
Sketch, labell and classify.
1. Hydra.
Answer:

Classification:
Kingdom: Animalia
Division: Non-chordata
Phylum: Coelenterata
Example: Hydra

2. Jellyfish
Answer:

Classification:
Kingdom: Animalia
Division: Non-chordata
Phylum: Coelenterata
Example: Jellyfish

3. Planaria
Answer:

Classification:
Kingdom: Animalia
Division: Non-chordata
Phylum: Platyhelminthes
Example: Planaria

4. Roundworm
Answer:

Classification:
Kingdom: Animalia
Division: Non-Chordata
Phylum: Aschelminthes
Example: Ascaris (Roundworm)

5. Butterfly
Answer:

Classification:
Kingdom: Animalia
Division: Non-chordata
Phylum: Arthopoda
Class: Insecta
Example: Butterfly

6. Earthworm
Answer:

Classification:
Kingdom: Animalia
Division: Non-chordata
Phylum: Annelida
Example: Earthworm

7. Octopus
Answer:

Classification:
Kingdom: Animalia
Division: Non-chordata
Phylum: Mollusca
Example: Octopus

8. star fish
Answer:

Classification:
Kingdom: Animalia
Division: Non-chordata
Phylum: Echinodermata
Example: Star fish

9. Shark
Answer:

Classification:
Kingdom: Animalia
Phylum: Chordata
Sub Phylum: Vertebrata
Class: Pisces
Example: Scoliodon (Shark)

10. Frog
Answer:

Classification:
Kingdom: Animalia
Phylum: Chordata
Sub Phylum: Vertebrata
Class: Amphibia
Example: Frog

11. Wall Lizard
Answer:

Classification:
Kingdom: Animalia
Phylum: Chordata
Sub Phylum: Vertebrata
Class: Reptilia
Example: Wall Lizard

12. Pigeon.
Answer:

Classification:
Kingdom: Animalia
Phylum: Chordata
Sub-Phylum: Vertebrata
Class: Aves
Example: Pigeon

Question 11.

Answer:
(1) Jellyfish
(2) Nereis
(3) Flatworm/Planaria
(4) Bony fish.

Project: (Do it your self)

1. In each week, on a specific day of your convenience, observe the animals present around your school and residence. Perform this activity for six months. Keep date-wise record of your observations. After the observation period of six months, analyse your observations with respect to seasons. With the help of your teacher, classify the reported animals.

Can you recall? (Text Book Page No. 61)

Question 1.
Which criteria are used for classification of organisms?
Answer:
The living organisms are classified according to their basic characteristics, such as presence or absence of nucleus, unicellular body or multicellular body, presence or absence of cell wall and the mode of nutrition in them.

Question 2.
How are the plants classified?
Answer:
The plants are classified according to the following basis:

1. Presence or absence of the organs.
2. Presence or absence of separate

Use your brain power: (Text Book Page No. 74)

(A) Animals like gharial and crocodile live in water as well as on land. Are they amphibians or reptiles?
Answer:
Ghariyal and crocodile are reptiles. They can swim in water and crawl on land. But they can respire only with the help of lungs. Their breathing is through nostrils. Even when in water, they have to inhale and exhale by coming up to the surface of water for air. Amphibians can breathe through the skin when in water and by lungs when on land. They also have hard exoskeleton which amphibians do not have. Hence, ghariyal and crocodile are not amphibians, but they are reptiles.

(B) Animals like whale, walrus live in water (ocean). Are they included in Pisces or Mammalia?
Answer:
Whale and walrus are aquatic and marine mammals. They do not belong to class Pisces. They do not have gills to breathe in dissolved oxygen in water. Neither they have scales on the body nor can they lay eggs. Whales and walrus have mammary glands like all other mammals. They give birth to live young one. They breathe only with the help of lungs by putting their nostrils out of the water at surface. Hence they are included in Mammalia.

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

Question 1.
System of classification based on evolution was brought into practice by ……….. and …………
(a) Darwin, Mendel
(b) Lamarck, De Vries
(c) Morgan, Mayor
(d) Dobzansky, Meyer
Answer:
(d) Dobzansky, Meyer

Question 2.
Artificial method of animal classification was proposed by ………….
(a) Aristotle
(b) Darwin
(c) Lamarck
(d) Whittaker
Answer:
(a) Aristotle

Question 3.
Animals attached to substratum are called ……….. animals.
(a) sessile
(b) sedentary
(c) lame
(d) motionless
Answer:
(b) sedentary

Question 4.
In coelenterates, ………… are useful for capturing the prey whereas ………. inject the toxin in the body of prey.
(a) tentacles, cnidoblast
(b) hands, legs
(c) flagella, sting
(d) cilia, sting cells
Answer:
(a) tentacles, cnidoblast

Question 5.
Body of annelidan animals is long, cylindrical and …………. segmented.
(a) annular
(b) metamerically
(c) jointed
(d) cuticular
Answer:
(b) metamerically

Question 6.
…………. is second largest phylum in animal kingdom.
(a) Mollusca
(b) Arthropoda
(c) Porifera
(d) Platyhelminthes
Answer:
(a) Mollusca

Question 7.
Endoskeleton of Cyclostomata animals is …………..
(a) bony
(b) bony and cartilaginous
(c) cartilaginous
(d) none of the above
Answer:
(c) cartilaginous

Question 8.
Body cavity between the body and internal organs is called ………….
(a) gastrocoel
(b) enteron
(c) coelom
(d) cave
Answer:
(c) coelom

Question 9.
Larvae of ……….. metamorphose into adults after settling down at bottom of the sea.
(a) Hemichdrdata
(b) Urochordata
(c) Cephalochordata
(d) Cyclostomata
Answer:
(b) Urochordata

Question 10.
The body organization of unicellular organisms is of …………. grade.
(a) cellular
(b) tissue
(c) protoplasmic
(d) organ
Answer:
(c) protoplasmic

Question 11.
………….. is a cold blooded animal. (March 2019)
(a) Bat
(b) Snake
(c) Rabbit
(d) Elephant
Answer:
(b) Snake

Question 12.
Calcareous spines are present on the body of ………… animal. (July 2019)
(a) fish
(b) snail
(c) sponge
(d) starfish
Answer:
(d) starfish

Question 13.
Due to which similar characteristic honey bee and cockroach are included in the same phylum?
(a) Wings
(b) Three pair of legs
(c) Jointed appendages
(d) Antenna
Answer:
(c) Jointed appendages

Write whether the following statements are true or false with proper explanation:

Question 1.
Greek philosopher Linnaeus was the first to perform the animal classification.
Answer:
False. (Greek philosopher Aristotle was the first to perform the animal classification.)

Question 2.
Heart if present in the non-chordates is on dorsal side of body.
Answer:
True.

Question 3.
Arthropoda animals bear numerous pores on their body.
Answer:
False. (Porifera animals bear numerous pores on their body.)

Question 4.
Porifera animals have special type of collar cells.
Answer:
True.

Question 5.
Aschelminthes have acoelomate and bilaterally symmetrical body.
Answer:
False. (Platyhelminthes have acoelomate and bilaterally symmetrical body. OR Aschelminthes have pseudocoelomate and bilaterally symmetrical body.

Question 6.
Planet Earth has highest number of animals from phylum Arthropoda.
Answer:
True.

Question 7.
Animals belonging to phylum Annelida perform locomotion with the help of tube-feet.
Answer:
False. (Animals belonging to phylum Echinodermata perform locomotion with the help of tube-feet.)

Question 8.
Herdmania has notochord in only tail region and hence it is called Urochordate.
Answer:
True.

Question 9.
Mammals breathe with the help of lungs.
Answer:
True.

Question 10.
Amphibians are warm blooded.
Answer:
False. (Amphibians are cold-blooded. OR Mammals are warm blooded.)

Match the columns:

Question 1.

Phylum	Characteristics
(1) Mollusca	(a) Collar cells
(2) Hemichordata	(b) Mantle
	(c) Trunk
	(d) Cnidoblasts

Answer:
(1) Mollusca – Mantle
(2) Hemichordata – Trunk.

Question 2.

Phylum	Characteristics
(1) Porifera	(a) Tunic
(2) Coelenterata	(b) Collar cells
	(c) Tentacles bearing cnidoblasts
	(d) Mantle

Answer:
(1) Porifera – Collar cells
(2) Coelenterata – Tentacles bearing cnidoblasts.

Question 3.

Subphylum/Class	Characteristics
(1) Cyclostomata	(a) Collar cells
(2) Urochordat	(b) Sucker
	(c) Tunic
	(d) Chitinous exoskeleton

Answer:
(1) Cyclostomata – Sucker
(2) Urochordata – Tunic.

Find the odd one out:

Question 1.
Physalia, Hyalonema, Ruplectella, Spongilla
Answer:
Physalia. (Physalia belongs to Coelenterata, all the remaining are poriferans.)

Question 2.
Planaria, Liverfluke, Filarial worm, Tapeworm
Answer:
Filarial worm. (Filarial worm is Aschelminthes remaining are Platyhelminthes.)

Question 3.
Star fish, Sea-urchin, Nereis, Sea-cucumber
Answer:
Nereis. (Nereis belongs to Annelida all the remaining are Echinoderm animals.)

Question 4.
Cockroach, Butterfly, Spider, Honey bee
Answer:
Spider. (Spider is eight-legged Arachnid, remaining are insects.)

Question 5.
Amphioxus, Herdmania, Doliolum,Oikopleura
Answer:
Amphioxus. (Amphioxus is Cepholochordate all the remaining are Urochordates.)

Question 6.
Frog, Tortoise, Toad, Salamander
Answer:
Tortoise. (Tortoise is a reptile, the remaining are amphibians.)

Question 7.
Tube feet, Setae, Parapodia, Sucker
Answer:
Tube feet. (Tube feet are locomotory organs of Echinoderms, the remaining are locomotory organs of Annelids.)

Question 8.
Shark, Sting ray, Electric ray, Pomfret
Answer:
Pomfret. (Pomfret is a bony fish, all the remaining are cartilaginous fish.)

Find the correlation:

Question 1.
Annelida : Earthworm : : Platyhelminthes : …………
Answer:
Annelida : Earthworm : : Platyhelminthes : Planaria/Liverfluke

Question 2.
Horse : Mammal : : Seahorse : ………….
Answer:
Horse : Mammal : : Seahorse : Pisces

Question 3.
Parapodia : Annelida : : Tube feet : ………..
Answer:
Parapodia : Annelida : : Tube feet : Echinodermata

Question 4.
Frog : Amphibia : : Turtle : …………..
Answer:
Frog : Amphibia : : Turtle : Reptilia

Question 5.
Proboscis : Hemichordata : : Suctorial mouth : …………
Answer:
Proboscis : Hemichordata : : Suctorial mouth : Cyclostomata

Question 6.
Bird from very cold regions : Penguin : : Aquatic Mammal from very cold regions : ………..
Answer:
Bird from very cold regions : Penguin : : Aquatic Mammal from very cold regions : Whale.

Distinguish between:

Question 1.
Non-chordates and Chordates.
Answer:
Non-chordates

1. Non-chordates are less evolved animals and are on the lower levels of evolution.
2. Non-chordates do not have notochord.
3. In non-chordates, there are no pharyngeal gill slits.
4. Nerve cord, if present is double and solid.
5. Nerve cord is located on the ventral side of the body.
6. Heart if present is on the dorsal side of the body.

Chordates:

1. Chordates are more evolved animals and are on the higher levels of evolution.
2. Chordates have notochord at least in some stage of development.
3. In chordates, there are pharyngeal gill slits.
4. Nerve cord is single and hollow.
5. Nerve cord is located on the dorsal side of the body.
6. Heart if present is on the ventral side of the body.

Question 2.
Phylum Platyhelminthes and Phylum Aschelminthes. OR Write any two points of differences between flat worms and round worms.
Answer:
Phylum Platyhelminthes (Flat worms):

1. Platyhelminth worms have slender and flat leaf or strip like body hence called flat worms.
2. Platyhelminthes are triploblastic and acoelomate.
3. Most of them are hermaphrodite or bisexual having both male and female reproductive systems in the same body.
4. Examples: Planaria, Liver fluke, Tapeworm, etc.

Phylum Aschelminthes (Round worms):

1. Aschelminthes have long thread-like or Cylindrical body, hence called round worms.
2. Aschelminthes are triploblastic and pseudocoelomate.
3. They are unisexual with male and female sexes separate. There is sexual dimorphism.
4. Examples: Ascaris (Intestinal worm), Filarial worm, Loa loa (Eye worm), etc.

Question 3.
Urochordata and Cephalochordata.
Answer:
Urochordata:

1. Urochordates have notochord in the tail region of the adult body.
2. These animals look like small sacs.
3. Usually urochordates are hermaphrodites.
4. Body of urochordate is covered over by skin-like test or tunic.
5. Examples: Herdmania, Doliolum, Oikopleura, etc.

Cephalochordata:

1. Cephalochrodates have notochord in the entire length of the body.
2. These animals look like small fish.
3. Cephalochordates are unisexual.
4. Body of cephalochordate is not covered in a test.
5. Example: Amphioxus.

Question 4.
Cyclostomata and Pisces.
Answer:
Cyclostomata:

1. Cyclostomata are the poorly evolved first class of vertebrate animals.
2. Cyclostomata have circular jawless mouth with suckers.
3. Paired appendages are absent in cyclostomates.
4. Cyclostomes have soft skin which is without any scales.
5. Endoskeleton is cartilaginous.
6. Examples: Petromyzon, Myxine, etc.

Pisces:

1. Pisces are the better evolved class of vertebrates which is well adapted for aquatic living.
2. Pisces have mouth with upper and lower jaws. Teeth are present in the mouth.
3. Paired and unpaired fins present in all kinds of fishes.
4. Fishes have different types of scales on the body.
5. Endoskeleton may be cartilaginous, or it may be bony.
6. Examples: Shark (Scoliodoh), rays which are cartilaginous fishes and pomfret, makerel, sardines, rohu which are bony fishes.

Question 5.
Amphibia and Reptilia.
Answer:
Amphibia:

1. Amphibians can inhabit both land and water. They can survive on both environments by breathing there.
2. The exoskeleton is absent in amphibians. The skin is soft, slimy and moist.
3. Body is divided into head and trunk. Neck is absent.
4. The digits do not have claws.
5. The respiration is by skin when in water and by lungs when on land. The larvae breathe by gills.
6. There is external fertilization at the time of sexual reproduction.
7. The developmental stages are eggs and tadpole. Metamorphosis is seen in amphibians.
8. Examples : Frog, Toad, Salamander, etc.

Reptilia:

1. Reptilians are terrestrial animals. Though turtle and sea snakes can stay in water, they cannot breathe in water.
2. The exoskeleton in the form of scales. Some animals have plates or scutes (e.g. tortoise and crocodile).
3. Body is divided into head, neck and trunk.
4. The digits have claws.
5. The respiration is only by lungs.
6. There is internal fertilization at the time of sexual reproduction.
7. The developmental stages are eggs and juvenile. Metamorphosis is not seen in reptiles.
8. Examples : Tortoise, Lizard, Snake, etc.

Question 6.
Aves and Mammalia.
Answer:
Aves:

1. Aves are totally adapted for the aerial mode of life.
2. Body is spindle shaped. Body is divisible into head, neck and trunk. There are two pairs of limbs. The forelimbs are modified to form wings for flight.
3. Digits have scales and claws.
4. The exoskeleton is in the form of feathers.
5. Jaws are modified into a beak.
6. Birds are oviparous. The eggs hatch into nestlings.
7. The incubation of eggs and feeding of nestlings is done by both parents.
8. Examples: Crow, Sparrow, Peacock, Parrot, Pigeon, Duck, Penguin, etc.

Mammalia:

1. Mammals are adapted for terrestrial life.
2. Body is not spindle shaped. It is divisible into head, neck, trunk and tail. There are two pairs of limbs. They are adapted for walking or running on the ground.
3. Digits have nails or hoofs. Few have claws.
4. The exoskeleton is in the form of fur, hair, wool, etc.
5. Jaws have teeth and they surround the mouth.
6. Mammals are viviparous. They give birth to live young ones. (Exception: Platypus)
7. Parental care is shown only by mother, who feeds, the babies with milk from mammary glands.
8. Examples: Cat, Dog, Tiger, Lion, Elephant, Human, Kangaroo, Dolphin, Bat, etc.

Classification-based questions:

Question 1.
Identify me:
(1) I am metamerically segmented, blood sucking, ectoparasite. I have suckers. Who am I and to what phylum do I belong to? (OR) Who am I? (July 2019)
I have suckers. I am blood sucking.
Answer:
Leech, Phylum Annelida.

(2) I have chitinous exoskeleton, I have four pairs of walking appendages. I can sting you. Who am I? What phylum do I belong to?
Answer:
Scorpion. Phylum Arthropoda.

Question 2.
Characters of a phylum are given below. Read them carefully and answer the questions:
(a) Spines of calcium carbonate are present on the body, (b) These animals are exclusively marine, (c) They perform the locomotion with the help of tube feet, (d) Their skeleton is made up of calcareous plates or spicules.
(i) Animals of which phylum show the above character?
Answer:
Animals belonging to phylum Echinodermata show the above characters.

(ii) Give an example from that phylum.
Answer:
Starfish, brittlestar, sea urchin.

(iii) These animals can be classified with the help of which criteria of new system of animals classification.
Answer:
Animals are classified on the basis of criteria such as body organization, body symmetry, body cavity, etc.

Question 3.
Identify my class/phylum and give one example of it: (March 2019)
(a) I have mammary glands and exoskeleton in the form of hair.
(b) We form the highest number of animals on the planet. We have bilateral symmetry and our exoskeleton is in the form of chitin.
(c) I live in your small intestine, my body is long and thread like and pseudocoelomate.
Answer:
(a) Class: Mammalia, Example: Cat, Dog, Man.
(b) Phylum: Arthropoda, Example: Prawn, Crab.
(c) Phylum: Aschelminthes, Example: Ascaris or round worm, Filarial worm.

Question 4.
Tell me who am I? What is my class/ phylum?
1. My body is divided into proboscis, collar and trunk. I am marine animal.
Answer:
Balanoglossus; Phylum: Hemichordata.

2. I stay inside two shells. My body is divided into head, foot and visceral mass.
Answer:
Bivalve or Oyster; Phylum: Mollusca.

3. I am male as well as female. I am endoparasite having a coelomate and bilaterally symmetrical and flattened body.
Answer:
Liver fluke or tape worm; Phylum: Platyhelminthes.

4. I am sedentary marine animal drinking water all the time through numerous pores on the body.
Answer:
Sponge; Phylum: Porifera.

5. I am venomous, eight legged creature having chitinous exoskeleton.
Answer:
Scorpion; Phylum: Arthropoda.

6. My body is covered by tunic. As a larva I swim but as an adult I settle down.
Answer:
Doliolum or Salpa; Phylum: Chordata subphylum : Urochordata.

Question 5.
Identify the class of given animals and write one characteristic of each animal:
(1) Kangaroq (2) Penguin (3) Crocodile (4) Frog (5) Sea-horse. (July 2019)
Answer:
(1) Kangaroo: Class Mammalia. It is a marsupial animal with pouch for development of offspring. Long hind limbs for jumping.
(2) Penguin: Class Aves. It is flightless bird. Body covered with thick feathery coat. Oviparous mode.
(3) Crocodile: Class Reptilia. It is a large animal seen near water bodies. Can swim in water but cannot respire in water. Body covered with exoskeleton of scaly plates. Limbs very weak in comparison with huge bodies.
(4) Frog: Class Amphibia. Shows aquatic as well as terrestrial mode. Can breathe with lungs and skin. No exoskeleton and skin is slimy.
(5) Sea-horse: Class Pisces. Bony fish. Highly modified body structure showing brood pouch for development of offspring gills for respiration, fins for swimming.

Answer the following questions:

Question 1.
State any four benefits of animal classification. (March 2019)
Answer:

1. Studying the different animals becomes easy when they are placed under different groups.
2. When few representative animals of the particular group are studied then the idea about other animals belonging to that group also becomes clear.
3. The animal evolution becomes easier to follow after studying classification.
4. The identification of animals can be done accurately.
5. Relationship of the different animals with each other and with other groups can be understood clearly.
6. Habitat of each animal and its role in nature is understood by classification.
7. Various adaptations are understood by learning classification.

Question 2.
Into which phyla is Non-chordata divided? In which three subphyla are Chordates divided?
Answer:
I. The phyla of Non-chordata:

• Protozoa
• Porifera
• Coelenterata or Cnidaria
• Platyhelminthes
• Aschelminthes
• Annelida
• Arthropoda
• Mollusca
• Echinodermata
• Hemichordata

II. The subphyla of Chordata:

• Urochordata
• Cephalochordata
• Vertebrata

Question 3.
Write the characteristics of chordates.
Answer:
Characteristics of Chordates:

1. All chordates possess notochord and pharyngeal gill slits in at least during some developmental stage.
2. Presence of single, tubular and dorsally located spinal cord and ventrally located heart.

Question 4.
Write the characteristics of vertebrates.
Answer:
Characteristics of vertebrates:

• In vertebrates, notochord is replaced by vertebral column.
• Development of head is complete.
• Well-developed cranium which protects the brain.
• Presence of endoskeleton which is either cartilaginous or bony.
• Presence of jaws as in Gnathostomata or absence of jaws as in Agantha.

Write short notes on:

Question 1.
(1) Benefits of classification.
Answer:

• Studying the different animals becomes easy when they are placed under different groups.
• When few representative animals of the particular group are studied then the idea about other animals belonging to that group also becomes clear.
• The animal evolution becomes easier to follow after studying classification.
• The identification of animals can be done accurately.
• Relationship of the different animals with each other and with other groups can be understood clearly.
• Habitat of each animal and its role in nature is understood by classification.
• Various adaptations are understood by learning classification.

Question 2.
Germinal layers.
Answer:

• During the initial embryonic period of any multicellular animal there is formation of germinal layers or germ layer.
• These germ layers give rise to new tissues in the developing animal.
• The primitive animals were diploblastic i.e. they have only two germ layers called ectoderm and endoderm.
• The higher animals are triploblastic, having three germ layers; ectoderm, mesoderm and endoderm.
• Cnidarians are diploblastic while all other animals are triploblastic.

Question 3.
Coelom.
Answer:

• Coelom means body cavity. It is situated between the body wall and the internal organs of the body.
• The coelom is formed during early embryonic life in case of multicellular animals. It is formed from either mesoderm or gut.
• Coelom when present in the body, those animals are called eucoelomate. Phylum Annelida onwards are eucoelomate animals. They are animals with true body cavity.
• Those animals in which coelom are absent are called acoelomate animals. Porifera, Cnidaria and Platyhelminthes are acoelomate animals.
• When coelom is not formed from mesoderm or gut, but formed from other tissues, it is called pseudocoelom. Only Aschelminthes animals have such coelom and hence they are called pseudocoelomate.

Question 4.
Notochord.
Answer:

• Notochord is an important feature of Chordates.
• Notochord is supporting rod like structure.
• This structure is present on the dorsal side of the animals.
• It keeps the nervous tissue separated from the rest of the tissues.
• In Hemichordates, the notochord is present in the proboscis.
• In Urochordates, the notochord is present in the tail region of the free swimming larvae.
• In Cephalochordates, the notochord lies throughout the length of the body.
• In vertebrates, notochord is replaced by the vertebral column.

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

Question 1.
(Linnaeus, Dobzhansky, Carl Woese, Theophrastus, Artificial method, Aristotle, Natural system, Traditional system)
Time to time, different scientists have tried to classify the animals. Greek philosopher ………… was the first to perform the animal classification. Aristotle classified the animals, according to the criteria like body size, habits and habitats. Classification proposed by Aristotle is known as ………… Besides Aristotle, artificial method of classification was followed by ……….., Pliny, John Ray and ……….. Later on,’………… of classification’ was followed. Natural system of classification was based on various other criteria. By the time, system of classification based on evolution was also brought into practice. It was used by …………. and Meyer. Recently, ……….. has also proposed the animal classification.
Answer:
Time to time, different scientists have tried to classify the animals. Greek philosopher Aristotle was the first to perform the animal classification. Aristotle classified the animals, according to the criteria like body size, habits and habitats. Classification proposed by Aristotle is known as ‘Artificial method’. Besides Aristotle, artificial method of classification was followed by Theophrastus, Pliny, John Ray and Linnaeus. Later on, ‘Natural system of classification’ was followed. Natural system of classification was based on various other criteria. By the time, system of classification based on evolution was also brought into practice. It was used by Dobzansky and Meyer. Recently, Carl Woese has also proposed the animal classification.

Question 2.
(neck, lungs, skin, exoskeleton, amphibian, metamorphose, aquatic, gills)
Class Amphibia consist of animals which are strictly ……….. only during their larval stages. At that time they breathe through their …………. Tadpoles are such stages which later ………… to form adult frog. Adult frog respires with the help of ………… when in water and with when on land. Thus, it is a true …………. For performing cutaneous respiration, i.e. respiration through skin, they lack ………. in any form. The skin is also kept moist by staying near the water bodies. Amphibians do not have a ………… but eyes are bulging and prominent, this solves the problems of vision.
Answer:
Class Amphibia consist of animals which are strictly aquatic only during their larval stages. At that time they breathe through their gills. Tadpoles are such stages which later metamorphose to form adult frog. Adult frog respires with the help of skin when in water and with lungs when on land. Thus, it is a true amphibian. For performing cutaneous respiration, i.e. respiration through skin, they lack exoskeleton in any form. The skin is also kept moist by staying near the water bodies. Amphibians do not have a neck but eyes are bulging and prominent, this solves the problems of vision.

Paragraph based questions:

1. Read the paragraph and answer the questions given below:
Locomotion is considered as an important j characteristics of the animals. However, animals belonging to Porifera are said to be sedentary. Every 1 other phylum has typical locomotory organs. E.g. Nereis crawls with the help of parapodia, whereas earthworm buries in soil by setae. Spiders have four pairs of walking legs, crab has five while all insects have three pairs of walking legs. The walking legs are also called appendages. Starfish moves with the help of tube feet. Snails and bivalves use muscular foot for locomotion. Birds flying with their spread out wings and fish swimming with their fins, both have spindle-shaped body tapering at both the ends. While flying or swimming such body offers least resistance during locomotion. Mammals have two pairs of limbs while animals like snakes are limbless. Other animals belonging to the class of snakes also have very weak limbs which make them creep on the ground.

Questions and Answers:

Question 1.
What are the locomotory organs in phylum Annelida?
Answer:
Annelidans have parapodia and setae as the locomotory organs.

Question 2.
Which phylum has a characteristic of jointed appendages?
Answer:
Phylum Arthropoda has a characteristic of jointed appendages.

Question 3.
Which the locomotory organ of animals belong to Phylum Mollusca?
Answer:
Animals belonging to Phylum Mollusca have strong muscular foot which is used for locomotion.

Question 4.
Which class of animals show weak legs?
Answer:
Class Reptilia belonging to subphylum vertebrata show weak legs.

Question 5.
In which class of animals the forelimbs are modified?
Answer:
Class Aves belonging to subphylum vertebrata have wings which are modified forelimbs.

Diagram based questions:

Question 1.
Sketch, label and classify the following organisms:
1. Liverfluke.
Answer:

Classification:
Kingdom: Animalia
Division: Non-chordata
Phylum: Platyhelminthes
Example: Liverfluke

2. Leench.
Answer:

Classification:
Kingdom: Animalia
Division: Non-chordata
Phylum: Annelida
Example: Leech

3. Cockroach:
Answer:

Classification:
Kingdom: Animalia
Division: Non-chordata
Phylum: Arthopoda
Class: Insecta
Example: Cockroach

Question 2.
Identify the animal given in the figure and label the figure:
1.

Answer:
Balanoglossus

2.

Answer:
Herdmania.

3.

Answer:
Amphioxus

4.

Answer:
Petromyzon.

5.

Answer:
bat

Question 3.
Identify the class of the animal shown in the figure and write any two characteristics.
Answer:
(1) The animal shown in the figure is bat.
(2) It belongs to class Mammalia of Subphylum Vertebrata. Phylum Chordata.
(3) Characteristics:
(i) Body is divided into head, neck, torso and tail. Patagium present for the flying mode. Nocturnal in habit. It is warm blooded.
(ii) Gives birth to live young ones. Mammary glands present for nourishing young ones.

Question 4.
Observe the figure and answer the following questions.

(a) To which phylum these organisms belong?
(b) Name the substance with which their body is covered.
(c) Name their organs of locomotion.
Answer:
(a) The starfish and the sea urchin shown in the figure belong to phylum Echinodermata.
(b) The body of echinoderm animal is covered with calcareous spines or ossicles/plates.
This is the substance covering the body is mostly calcium salts and compounds.
(c) Their locomotory organs are tube feet.

Question 5.
Observe the figures given below and answer the given questions: (Board’s Model Activity Sheet)

(a) In which phylum are these animals included?
(b) Which substance forms the outer layer of their exoskeleton?
(c) What are their locomotory organs?
Answer:
(a) These animals are included in phylum Arthropoda.
(b) The outer layer of their exoskeleton is covered by chitinous substance.
(c) Their locomotory organs are jointed paired appendages.

Question 6.
Identify the phylum of the given animal and write any two characteristics of this phylum. (Board’s Model Activity Sheet)
Answer:

This animal is Sycon sponge and its phylum in Porifera.
Characteristics of phylum Porifera
(a) Asymmetrical body.
(b) Many pores on body. Large osculum and smaller ostia.

Question 7.
(a) Identify the animal given here.
(b) Write the phylum to which it belongs.
(c) Identify the pointed parts; p, q, r and s.

Answer:
(a) The given animal is Octopus.
(b) It belongs to the phylum Mollusca.
(c) p = eye, q = sucker, s = siphon and r = tentacle.

Complete the following charts:

Question 1.
Complete the chart by taking into consideration the criteria for classification: (Text Book Page No. 61)

Answer:

Question 2.
Complete the following flow-chart.

Answer:
(A) Eukaryotes
(B) Monera.

Activity based questions:

Question 1.
Observe: (Text Book Page No. 65)
(1) Body organization of human has been shown in the following figure. Use appropriate labels for different organs present in human body.

Answer:
There are different organs in the human body. The liver, pancreas, stomach, intestine, etc. related to the digestive system and a pair of kidney concerned with excretion is present in the abdominal cavity. The cranial cavity shows brain and sense organs. In the thoracic cavity there are lungs and heart. In addition to these organs, there are network of blood capillaries, nerve network, etc. which is spread from head to toes.

Question 2.
Why is earthworm called as friend of farmers? (Get Information: Text Book Page No. 69)
Answer:
Earthworms move through the soil in the farms and fields. They feed on the detritus in the soil. They also help in decomposition of the organic matter. When the soil is loosened due to their activities, the roots of the crops grow well. They enrich the soil by their excreta which act as fertilizers. All these facts make earthworm, a farmer’s friend.

Question 3.
In what way the leech is used in ayurvedic system of treatment? (Get Information: Text Book Page No. 69)
Answer:
Leeches are blood sucking ectoparasite. In Ayurveda leech is used to remove impure blood and blood clots. Such blood is sucked up by leeches and then the patient gets some relief. In the leech body there is. a substance called hirudine which prevent blood clotting as it sucks up the blood. This hirudine is also used for medicinal purpose.

Question 4.
What is chitin? (Find out: Text Book Page No. 70)
Answer:
Chitin is a type of polysaccharide. Its chemical formula is (C8H13O5N)n. It is a long-chain polymer of N-acetylglucosamine, which is actually a derivative of glucose. It is a primary component of cell walls in fungi, the exoskeletons of arthropods, such as crustaceans and insects. In many medicines chitin is used. The industrial processes and the biotechnological experiments also use chitin.

Question 5.
Let’s Think: (Text Book Page No. 70)
(i) What types of benefit and harm occur to human from animals of phylum-Arthropoda?
Answer:
Some insects are very useful for us. We get many products from them. e.g. Honey bee, Lac insect, Silk worm, are the insects that provide us with honey and wax, lac and silk respectively. The culture experiments are done on these insects for large scale production of these substances. Butterflies help in the pollination of crops and are thus helpful for the farmers and gardeners. Lady bug beetle is an insect which acts as a natural pest control as it attacks the other harmful insect pests.

In biological pest control methods it is widely used. Some insects, on the contrary are very harmful. Mosquito, bed bugs, lice are blood sucking parasites which can spread the diseases. Mosquito is a vector for dengue, filariasis and malaria. Some are biting insects that can cause wounds, some cause allergies of various kinds. The grains and crops are destroyed to great extent by the insects. In this way the insects belonging to the phylum Arthropods are harmful to health, wealth and peace of mind too.

(ii) Which are the animals from phylum Arthropoda those have shortest and longest life span?
Answer:
The shortest life span: May fly – About 24 hours. The longest life span : Lobster (Homarus americanus) – About 100 years.

(iii) Why has it been said that only insects directly compete with humans for food?
Answer:
The standing crop in the fields can be totally ruined by insects. The locust can damage the crops when they attack in thousands at a time. The grains are also infested by variety of insects like ants, weevils, beetles, etc. Therefore, we can say that only insects compete with humans for food.

Project: (Do it your self)

Project 1.
How does the infection of tapeworm in man, liver fluke in grazing animals like goat and sheep occur and what are their preventive measures? (Collect the Information, Internet is my friend: Textbook page no. 69)

Project 2.
How does the infection of round worms like Ascaris, filarial worm and plant nematodes occur and what are their preventive measures and treatment? (Collect the Information, Internet is my friend: Textbook page no. 69)

Project 3.
Books are my friend: Collect the information about pearl production from bivalves by reading appropriate books. (Textbook page no. 70)

Project 4.
Book are my friends: The Animal Kingdom: Libbie Hyman and some other similar books.
(Textbook page no. 75)

Project 5.
Use of Information Technology: (Textbook page no. 75)
Prepare the presentation of animal classification using video clips downloaded from internet.

Balbharti Maharashtra State Board Class 10 Hindi Solutions Lokbharti Chapter 7 खुला आकाश Notes, Textbook Exercise Important Questions and Answers.

Maharashtra State Board Class 10 Hindi Lokbharti Chapter 7 खुला आकाश

Hindi Lokbharti 10th Std Digest Chapter 7 गिरिधर नागर Textbook Questions and Answers

सूचना के अनुसार कृवियाँ कीविए:
(1) प्रहवलका पूण् कीविए:

उतर:

(2) कृवि पूण् कीविए:

उतर:

(3) आकृवि मे वलखिए:

उतर:

(4)

उतर:

(5) लखिए:
a.

उतर:

b.

उतर:

भाषा हबंदु
(1) हनम्हलखखत संहध हिचछेद की संहध कीहजए और भेद हलखखए:

उतर:

संधि शब्द	संधि विच्छेद	संधि भेद
(i) सज्जन	सत् + जन	व्यंजन संधि
(ii) नमस्ते	नमः+ ते	विसर्ग संधि
(iii) स्वागत	सु + आगत	स्वर संधि
(iv) दिग्दर्शक	दिक् + दर्शक	व्यंजन संधि
(v) यद्यपि	यदि + यपि	स्वर संधि
(vi) दुस्साहस	दुः + साहस	विसर्ग संधि

(2) हनम्हलखखत शब् का संहध हिचछेद कीहजए और भेद हलखखए:

उतर:

संधि विच्छेद	संधि शब्द	संधि भेद
(i) दुः +  लभ	दुर्लभ	विसर्ग संधि
(ii) महा +  आत्मा	महात्मा	स्वर संधि
(iii) अन् +  आसक्त	अनासक्त	स्वर संधि
(iv) अंतः +  चेतना	अंतश्चेतना	विसर्ग संधि
(v) सम् +  तोष	संतोष	व्यंजन संधि
(vi) सदा + एव	सदैव	स्वर संधि

(3) हनम्हलखखत आकृहत मे हदए गए शब् का हिचछेद कीहजए और संहध का भेद हलखखए:

उतर:

संधि शब्द	संधि विच्छेद	संधि भेद
(i) दिग्गज’	दिक् + गज	व्यंजन संधि
(ii) सप्ताह	सप्त + अह	स्वर संधि
(iii) निश्चल	निः + चल	विसर्ग संधि
(iv) भानूदय	भानु + उदय	स्वर संधि
(v) निस्संदेह	निः + संदेह	विसर्ग संधि
(vi) सूर्यास्त	सूर्य + अस्त	स्वर संधि

(4) पाठो मे आए संहध शब् छाँटकर उनका हिचछेद कीहजए और संहध का भेद हलखखए।

संधि शब्द	संधि विच्छेद	संधि भेद
(i) निर्जीव	निः + जीव	विसर्ग संधि
(ii) संभव	सम् + भव	व्यंजन संधि
(iii) उज्ज्व	लउत् + ज्वल	व्यंजन संधि

Hindi Lokbharti 10th Textbook Solutions Chapter 7 खुला आकाश Additional Important Questions and Answers

गद्यांश क्र.1
कृति 1: (आकलन)
(1) आकृति पूर्ण कीजिए:

उत्तर:

(2) उत्तर लिखिए: (बोर्ड की नमूना कृतिपत्रिका)

उत्तर:

कृति 2: (स्वमत अभिव्यक्ति)

‘बढ़ती हुई जनसंख्या का मनुष्य जीवन पर प्रभाव’ के बारे में आपके विचार 25 से 30 शब्दों में लिखिए। (बोर्ड की नमूना कृतिपत्रिका)
उत्तर:
आज लगभग सभी देशों की जनसंख्या में बढ़ोत्तरी हो रही है। यह जनसंख्या वृद्धि आज संसार के समक्ष एक समस्या बन गई है। सभी देशों के संसाधन सीमित हैं और बढ़ी हुई जनसंख्या की माँग विशाल है, जिसकी पूर्ति करना संभव नहीं है। इसी का परिणाम है कि आज लोगों के सामने बेकारी की समस्या उत्पन्न हो गई है। जनसंख्या वृद्धि के कारण कृषि पर आधारित लोग परेशान हैं। खेती योग्य जमीन बँटती जा रही है।

अब वह इतने लोगों को रोटी देने में असमर्थ हो गई है। गाँवों की आबादी का बोझ शहरों पर आ पड़ा है। यहाँ शहरों में बेकारी की समस्या है। यहाँ भी लोग रोटी, कपड़ा, मकान की समस्याओं से जूझ रहे हैं। लोग गंदी बस्तियों में रहने के लिए मजबूर हैं। न इतने लोगों के लिए ढंग की शिक्षा व्यवस्था उपलब्ध हो पा रही है और न ही चिकित्सा व्यवस्था।

बढ़ती जनसंख्या ने देश की अर्थव्यवस्था बिगाड़ दी है। इस पर अंकुश लगाकर ही इस समस्या से छुटकारा पाया जा सकता है। तभी मनुष्य के जीवन स्तर में भी सुधार हो पाएगा।

गद्यांश क्र.2
प्रश्न.
निम्नलिखित पठित गद्यांश पढ़कर दी गई सूचनाओं के अनुसार कृतियाँ कीजिए:

कृति 1: (आकलन)
(2) सही विकल्प चुनकर वाक्य फिर से लिखिए:
(i) बिलकुल चुपचाप बैठकर सिर्फ ………………………… बारे में सोचें। (मेरे/अपने/सबके)
(ii) दूसरों की सोच-समझ पर ………………………… रखें। (भरोसा/प्रेम/संदेह)
(iii) ………………………… अन्य नहीं, अंतमय है, हमारे ही प्रतिरूप, हमसे अलग या भिन्न नहीं। (दूसरा /सब/वह)
(iv) ………………………… तरह सारे मनुष्य केवल मनुष्य होते और कुछ नहीं। (इसी/उसी/किसी)
उत्तर:
(2) (i) बिलकुल चुपचाप बैठकर सिर्फ अपने बारे में सोचें।
(ii) दूसरों की सोच-समझ पर भरोसा रखें।
(iii) दूसरा अन्य नहीं, अंतमय है, हमारे ही प्रतिरूप, हमसे अलग या भिन्न नहीं।
(iv) उसी तरह सारे मनुष्य केवल मनुष्य होते और कुछ नहीं।

कृति 2: (स्वमत अभिव्यक्ति)

‘आत्मचिंतन के लाभ’ विषय में अपने विचार 25 से 30 शब्दों में लिखिए।
उत्तर:
आत्मचिंतन यानी स्वयं के विषय में चिंतन करना। आत्मचिंतन का अर्थ है किसी कार्य को करने या होने के बाद उसे करने के लिए अपनाई. गई क्रिया और विचार पद्धति का विश्लेषण। आत्मचिंतन के द्वारा हमें अपनी गलतियों से सीखने, साथ ही अपने किए गए कार्य को और बेहतर ढंग से करने का मौका मिलता है। किसी भी व्यक्ति को कोई दूसरा जितना सिखा सकता है, उससे कहीं अधिक वह अपने स्वाध्याय एवं आत्मचिंतन के द्वारा सीख सकता है। इस प्रक्रिया में हम शांत भाव से बैठकर किसी समस्या या मुद्दे के बारे में चिंतन कर सकते हैं।

छात्र जीवन में तो इसकी और भी अधिक आवश्यकता है। अपनी क्षमताओं के विषय में अच्छी तरह जाने-समझे बिना हम लक्ष्य निर्धारित कर लेते हैं। शीघ्रातिशीघ्र उसे प्राप्त कर लेना चाहते हैं और बाद में भटक जाते हैं। इसलिए पहले आत्मचिंतन करें, स्वयं को जानें, फिर लक्ष्य प्राप्ति का प्रयास करें।

गद्यांश क्र. 3
प्रश्न.
निम्नलिखित पठित गद्यांश पढकर दी गई ‘सूचनाओं के अनुसार कृतियाँ कीजिए:

कृति 1: (आकलन)
(1) उत्तर लिखिए:

उत्तर:

कृति 2: (स्वमत अभिव्यक्ति)

‘जीवन की सार्थकता के विषय में अपने विचार 25 से 30 शब्दों में लिखिए।
उत्तर:
ईश्वर ने हमें सर्वश्रेष्ठ योनि अर्थात मानव योनि में जन्म दिया है। हमारा कर्तव्य है कि हम मानव जाति के लिए कुछ अच्छा कार्य करें। हमें जितनी आयु मिली है, वह समय हम अच्छे कार्यों को करने में लगाएँ। कुछ ऐसा काम करें जिससे समाज और देश का हित हो।

कुछ लोग समय की कमी की बात करते हैं। लेकिन यदि कुछ करने की लगन हो तो समय आड़े नहीं आता। स्वामी विवेकानंद 40 वर्ष की आयु से भी पहले इस संसार से चले गए। ईसा मसीह का 30 वर्ष की आयु में ही प्राणांत हो गया। रामानुजम, रानी लक्ष्मीबाई, नेपोलियन, सिकंदर और अन्य अनेक अल्पायु में ही इस असार संसार को छोड़ गए, फिर भी मानव इतिहास में, ये महापुरुष अपनी छाप छोड़ गए।

सीमित समय में भी जितना अधिक-से-अधिक अच्छा हो सके, हमें देश व समाज के कल्याण के लिए कुछ सकारात्मक अवश्य करना चाहिए।

गद्यांश क्र. 4
प्रश्न.
निम्नलिखित पठित गद्यांश पढ़कर दी गई सूचनाओं के अनुसार कृतियाँ कीजिए:

कृति 1: (आकलन)
(1) आकृति पूर्ण कीजिए:

उत्तर:

(2) जोड़ियाँ मिलाइए:

अ	आ
(i) शौक	भविष्य
(ii) एकनिष्ठ	गुलाम
(ii) उज्ज्वल	रास्ते
(iv) दरजनों	सेवा

उत्तर:

अ	आ
(i) शौक	रास्ते
(ii) एकनिष्ठ	सेवा
(iii) उज्ज्वल	भविष्य
(iv) दरजनों	गुलाम

कृति 2: (स्वमत अभिव्यक्ति)

→ ‘जो हम शौक से करना चाहते हैं, उसके लिए रास्ते निकाल लेते हैं, इसका सोदाहरण अर्थ 25 से 30 शब्दों में लिखिए।
उत्तर:
जिन कामों या चीजों का हमें शौक होता है, जिसमें हमारी रुचि होती है, उसके लिए हम समय, विधा सब निकाल लेते हैं। रुचि सफलता की वाहक है। हम सभी अपनी रुचि के कामों को करते समय उसमें डूब जाते हैं। उसी का परिणाम होता है सफलता। शिक्षा काल में जिस विषय में हमारी रुचि होती है, उसे पढ़ने में हम सारी रात भी जग लेते हैं, जबकि किसी ऐसे विषय की पुस्तक खोलते ही आँखें नींद से भर आती हैं, जो हमें पसंद न हो।

व्यायाम, तैराकी, बागवानी, चित्रकला, गायन, वादन आदि ऐसे अनेक कार्य हैं, जिनका यदि शौक हो तो मनुष्य घंटों बिताने पर भी उनसे ऊब अनुभव नहीं करता। किसी भी काम में सफलता प्राप्त करने के लिए उसमें रुचि होना परम आवश्यक है। बिना रुचि के आगे बढ़ने की संभावना बहुत कम होती है। जिस काम में हमारी रुचि होती है, उसे करने के लिए हम अपनी सारी ऊर्जा लगा देते हैं। न दिन देखते हैं, न ही रात। थकान शब्द तो मानो हमारे शब्दकोश में कभी था ही नहीं।

→ ‘कंप्यूटर ज्ञान का महासागर’ विषय पर तर्कपूर्ण चर्चा कीजिए।
उत्तर:
कंप्यूटर इस पृथ्वी पर कल्पवृक्ष के समान है। जीवन का कोई भी ऐसा क्षेत्र नहीं है, जहाँ इसका महत्व न हो। सूचना के क्षेत्र में कंप्यूटर के कारण अद्भुत क्रांति आ गई है। इंटरनेट इसकी अनुपम देन है। दुनियाभर की जानकारी हम मिनटों में प्राप्त कर सकते हैं। यह एक सेकंड में दस हजार करोड़ गणितीय गणना कर सकता है।

चाहे मौसम का पूर्वानुमान हो या प्राकृतिक गैस और खनिज भंडारों का पता लगाना हो, रेलगाड़ियों और हवाईजहाजों का आरक्षण कराना हो या संसारभर की जानकारी प्राप्त करनी हो, कंप्यूटर के द्वारा घर बैठे हम मिनटों में कर सकते हैं। यह समय-समय पर भौगोलिक सूचनाओं से संबंधित जानकारी भी देता है। मुद्रण व प्रसारण के क्षेत्र में इसका योगदान असीमित है।

कंप्यूटर एक चालक की भाँति वायुयान का संचालन करता है। चालक के बटन दबाते ही कंप्यूटर स्वयं गति और दिशा का निर्धारण कर लेता है। शिक्षा के क्षेत्र में तो आज कंप्यूटर एक अनिवार्यता बन गया है।

→ महानगरीय/ग्रामीण दिनचर्या के लाभ तथा हानि के बारे में अपने अनुभव के आधार पर लिखिए।
उत्तर:
गाँवों में आज भी खुला आसमान है। वहाँ का वातावरण शुद्ध, प्रकृति की गोद में है, जबकि महानगरों में आसमान दिखाई नहीं पड़ता। बड़े पैमाने पर वाहनों से होने वाला प्रदूषण, लगातार होने वाला शोर, भीड़ और धुआँ असहज महसूस कराता है। भीड़भाड़, ट्रैफिक जाम, और अपराध महानगरों में रोज की बात है। गाँवों में एक प्रकार का ठहराव है। शाम ढलते ही चारों ओर एक प्रकार का सन्नाटा पसर जाता है।

जबकि, महानगरों में जीवन हर समय गतिमान रहता है। देर रात तक ऑफिस, दुकानें खुली रहती हैं। बस, ट्रेन, टैक्सियाँ, स्कूटर्स सड़कों पर दौड़ते रहते हैं। गाँवों में धूप, हरियाली और शांति का आनंद प्राप्त कर सकते हैं। लोग आज भी गर्मजोशी से मिलते हैं। एक-दूसरे के दुख-तकलीफ में काम आते हैं। महानगरों में बहुत-से लोग पड़ोसी तक को नहीं पहचानते। दोस्तों, रिश्तेदारों के लिए समय नहीं निकाल पाते।

यहाँ लोगों के पास पैसा है, सुविधाएँ हैं, पर शांति कोसों दूर है। ग्रामीण लोगों का जीवन महानगरों की भागदौड़ से दूर एवं प्रकृति के करीब होता है। दूसरी ओर महानगरों में लोग हमेशा समय को पकड़ने के लिए दौड़ते रहते हैं। अति व्यस्तता के कारण तनाव, फिर स्वास्थ्य। संबंधी विभिन्न परेशानियाँ उन्हें घेर लेती हैं।

अपवठि ग‍दयांश

नम्वलखिि पररचछे‍ पढ़कर सूचना के अनुसार कृवियाँ कीविए:

हर फकसी को आतमरक् करनी होगी, हर फकसी को अपना कत्यय करना होगा। मै फकसी की सहायता की प्राशा नही करता। मै फकसी का भी प्राह नही करता। इस दुफनया से मदद की प्र्या करने का मुझे कोई अफधकार नही है। अतीत मे फिन लोगो ने मेरी मदद की है या भफ‍व् मे भी लोग मेरी मदद करें, मेरे प्र उन सबकी करुण मौिूद है, इसका दा‍व कभी नही फकया सकता। इसीफलए मै सभी लोगो के प्र फचर कक तज ञँ।

तुमहारी पररफस्फत इतनी बुरी देखकर मै बेहद फचंफतत हँ। लेफकन यह लो फक-‘तुमसे भी जयादा दुखी लोग इस संसार मे है। मै तुमसे भी जयादा बुरी पररफस्फत मे हँ। इंग् मे सब कुछ के फलए मुझे अपनी ही िेब से खच् करना पड़ता है। आमदनी कुछ भी नही है। लंदन मे एक कमरे का फकराया हर सप्ह के फलए तीन पाउंड होता है। ऊपर से अनय कई खच् है। अपनी तकलीिो के फलए मै फकससे फशकायत करू? यह मेरा अपना कम्यल है, मुझे ही भुगतना होगा।’

(फ‍ववकानंद की आतमकथा से)

(1) कृवि पूण् कीविए:
1.

2.

(2) उतिर वलखिए:
1. पररचछेद मे उखलिखत देश – [ ]
2. हर फकसी को करना होगा – [ ]
3. लेखक की तकलीिे – [ ]
4. हर फकसी को करनी होगी – [ ]

(3) वन‍देानुसार हल कीविए:
(अ) वनम्वलखिि अर् से मेलनेला शब् उपयु्थ् पररचछे‍ से ढूँढ़कर वलखिए ः
1. स्वं की रक् करना – …………………………….
2. दूसरो के उपकारो को मानने ‍वला – …………………………….

(4) लंग पहचानकर वलखिए:
1. जेब [ ]
2. साहित्य [ ]
3. दावा [ ]
4. सेवा [ ]

खुला आकाश Summary in Hindi

विषय-प्रवेश : प्रस्तुत पाठ डायरी विधा का एक उदाहरण है। कुँवर नारायण जी ने इस पाठ के माध्यम से नगरों की भीड़, वहाँ की जीवन-शैली, जीवन के संघर्ष, आत्मचिंतन आदि पर प्रकाश डाला है। लेखक मानते हैं कि व्यक्ति के विकास में आत्मचिंतन का बड़ा महत्त्व है। इसके द्वारा हम अपनी क्षमताओं के बारे में और अधिक जान सकेंगे। साथ ही अपनी गलतियों से सीख ले सकेंगे।

Balbharti Maharashtra State Board Class 10 History Solutions Chapter 4 History of Indian Arts Notes, Textbook Exercise Important Questions and Answers.

Maharashtra State Board Class 10 History Solutions Chapter 4 History of Indian Arts

Question 1.
(A) Choose the correct option from the given options and complete the statement.
(1) The arts of painting and sculpting are …………….……. .
(a) visual arts
(b) performing arts
(c) folk arts
(d) classical arts
Answer:
(a) visual arts

(2) The …………….……. saw the rise of Mathura school.
(a) Kushana period
(b) Gupta period
(c) Rashtrakuta period
(d) Maurya period
Answer:
(a) Kushana period

(B) Identify and write the wrong pair in the following set.
(1) Qutub Minar – Mehrauli
(2) Gol Gumbaz – Vijapur
(3) Chhatrapati Shivaji Maharaj Railway Terminus – Delhi
(4) Taj Mahal – Agra
Answer:
(3) Wrong Pair: Chhatrapati Shivaji Maharaj Railway Terminus – Delhi

Question 2.
Write short notes.
(1) Art
Answer:

• It is a natural instinct in humans to share their emotions, experience, wisdom acquired with others.
• This act of sharing, results in beautiful creation, called an ‘Art’.
• Art gives us an experience of different elements.
• These elements are expressed through sculpture, singing, painting and dance.
• The crucial factors which are at the root of artistic creation are the imagination power of the artist.
• The sensibility state of his emotions and skills.

(2) Hemadpanti style
Answer:

1. Hemadpanti temples were primarily built in 12th- 13th century.
2. The main feature of this style is its masonry. The walls are built without mortar, by locking stones, using the tenon and mortise joints technique.
3. Hemadpanti temples are built in square¬shaped and star-shaped designs. In the star¬shaped plan, the outer walls of a temple has a zigzag design which gives interesting effect of alternating light and shadow.
4. Tourists are attracted to see these beautiful designs. Hemadpanti temples are found at several places in Maharashtra.

(3) Maratha style of painting
Answer:

• The Maratha style of paintings began to develop in the later half of the 17th century.
• This style consists of coloured paintings which are in form of murals and miniatures used in manuscripts.
• Murals of Maratha style can be seen at the entrance of old wadas, in drawing rooms and on the ceilings of the temples.
• The Maratha style was influenced by the Rajput and European style of paintings.
• The Maratha style of paintings helps us to understand various things about the times in which it was developed such as lifestyle, attires, customs, etc.

Question 3.
Explain the following statements with reasons.
(1) An expert with deep understanding of art history is required in the art market.
Answer:

• There is an independent market for purchase and sale of art objects.
• The authenticity of the object, its standards can only be assessed by an expert.
• Only an artist can know the exact value of an art object or ensure if it is genuine or not.
• So, when art objects are assessed all the above points are considered.
• This requires special expertise. Hence an expert with deep understanding of art history is required for this task.

(2) It is necessary to preserve the tradition like Chitrakathi, which is on the verge of extinction.
Answer:

1. The stories from Ramayana or Mahabharata narrated with the help of wooden puppets and paintings is known as Chitrakathi or Pinguli tradition.
2. It is preserved by the Thakur community.
3. As the Chitrakathi pictures are drawn on papers and painted using col9urs made from natural substances, they deteriorate rapidly if not maintained.
4. Therefore it is necessarý to preserve the tradition like Chitrakathi as it is part of our glorious cultural heritage and is on the verge of extinction.

Question 4.
Complete the following table.

Temple Architecture Naagara	Naagara	Draavida	Hemadpanti
Characteristics
Examples

Answer:

Styles of Temple Architecture	Nagara	Dravid	Hemadpanti
Characteristics	(1) Series of miniature towers are arranged (2) Towers taper towards the top (3) Tower appears to be continuously rising from the base of the temple to the top.	(1) Temple towers resembled pyramid shape. (2) Gopura (main entrance) was large and magnificent than the tower. (3) Mythological stories were carved on walls and ceilings.	(1) The temple structure was star-shaped with outer walls having zigzag design. (2) The walls were built without using any mortar. (3) The stones were locked by using the technique of tenon and mortise joints.
Examples	(1) Konark Sun Temple (2) Lingraj Temple of Bhubaneshwar (3) Kandariya Mahadev temple at Khajuraho	(1) Meenakshi Temple at Madurai (2) Chariot Temple at Mahabalipuram (3) Brihadeeshvara temple at Thanjavur (4) Tirupati Temple	(1) Gondeshwar temple at Sinnar (2) Ambreshwar temple at Ambarnath (3) Aundha Nagnath temple at Hingoli (4) Kopeshwar temple at Khidrapur

Question 5.
Answer the following questions in detail.
(1) Write in detail about folk styles of painting.
Answer:

• The art of rock painting dates back to Stone Age. These rock paintings have preserved the style of folk painting.
• Rock paintings usually depict humans, animals and geometric figures.
• The style of rock paintings seems to be changing according to the cultural changes from Stone age to the beginning of agriculture.
• Man started depicting flora and fauna in a different style and also figures.
• There was difference in colours too. Black and Red were used in rock paintings.
• Colours extracted from natural substances were used.
• The man started using the knowledge he got from the surroundings and nature and depicted it in the pictures.
• In the later stage of development, man started customs such as decorating the walls and courtyards (Rangawali).
• By drawing various figures and symbols or using panels of painting to narrate stories. It helped in the development of folk paintings.

(2) Explain the characteristics of the Islamic architecture in India by giving examples.
Answer:
A blend of Persian, Central Asian, Arabic and pre Islamic native Indian styles created the Islamic architecture of India.
Following are the characteristics of Islamic architecture developed in the medieval period under the patronage of Muslim sultanates:

• Built in Islamic style, the Kutub Minor is the highest minaret in the world. It is 73 metres (240 ft) in height.
• The Taj Mahal built by the Mughal emperor Shah Jah’an is looked’ upon as the paramount* example of Islamic’architecture.
• The Gol Gumbaz at Bijapur in Karnataka built in 17th century is known for its echo which can be heard many times.
• The forts at Agra and Delhi are known for their massive walls of redstone.
• The walls are interrupted by graceful curves and lofty bastions. Red sandstone, domes, arches, minarets, magnificance all combined form characteristics of Islamic architecture.

(3) What kind of professional opportunities are available in the field of arts?
Answer:
Various opportunities are available in different fields of art:

1. Art historian can work in field of journalism. Art students can work in museums, archives, libraries. Information Technology, archaeological research and Indology contribute to recently developed fields like Heritage Management and Cultural Tourism.
2. An expert in art is required to assess the exact value of an art object and also in its sale and purchase. Experts are required in the field of manufacturing of objects for home decoration.
3. Ornaments, artistic creations of metals, earthen pots with colourful designs, objects made from cane and bamboo, beautiful glass objects, attractive textiles and clothing all come are under applied arts.
4. These fields require experts in manufacturing and sales. Hence many opportunities of employment are available in the field of arts.

(4) Observe the illustration of Warli painting on p. 23 and write about:
(a) Depiction of nature
(b) Drawings of human figures
(c) Depiction of occupations
(d) Houses
Answer:

The traditions of Warli painting and Pingul or Chitra Katha in Maharashtra are among the finest examples of folk style of paintings. Divya Somya Mashe, the artist in Thane district has played a great role in making the Warli style of paintings very popular. He has been honored with a number of national and international awards for his paintings. In the year 2011, he was awarded ‘Padmashree’.

Name of the painting tradition:
This picture is from Warli tradition.

Nature’s description:
Artist has sketched trees, leaves and shrubs in the picture. A fish is also drawn.

Sketch of human activities:
Women dancing in a circular pattern is also sketched in the picture.

Designing features:
Pictures of men, women and children are sketched. Warli paintings do not portray the exact objects but only a sketch. Human figures are drawn with the help of a triangle, circle and square which are placed at the tip.

Project
(1) Collect additional information of the World Heritage sites in India.
(2) Observe the sculptors or image-makers at work in your locality and interview them.
Answer:

Memory Map

Question 6.
Complete the sentences by choosing a correct option:
(a) Lalit Kala is also known as …………………… .
(a) Folk art
(b) Aangik Kala
(c) Drik Kala
(d) Nagara art
Answer:
(b) Aangik Kala

(b) Jivya Somya Mashe, an artist in the Thane district played a great role in making the …………………… style of painting very popular.
(a) Chitrakathi
(b) Maratha
(c) Warli
(d) Classical
Answer:
(c) Warli

(c) The Chalukya King, Someshvara, mentioned in …………………… book the tradition of Chitrakathi.
(a) Natyashastra
(b) Kitab-e-Navras
(c) Paintings of Ajanta
(d) Manasollas
Answer:
(d) Manasollas.

(d) The ancient Indian texts mentioned …………………………. styles of Classical Art.
(a) Nine
(b) Thirty-six
(c) Sixty-four
(d) Eighty-four
Answer:
(c) Sixty-four

(e) During the reign, of Mughal Emperor …………………………., the Mughal miniature style showing a blend of Indian and Persian was developed.
(a) Akbar
(b) Aurangzeb
(c) Jahangir
(d) Babur
Answer:
(a) Akbar

(f) Some of the drawings of Gangaram Tambat are preserved in …………………………. university.
(a) Stanford
(b) Cambridge
(c) Oxford
(d) Yale
Answer:
(d) Yale

(g) …………………………. is the characteristic of European style of painting.
(a) Sketching
(b) Exact portrayal of object
(c) Natural colours
(d) Landscape
Answer:
(b) Exact portrayal of object

(h) Replicas of Ajanta paintings was made by
(a) Pestonji Bomanji
(b) Gangaram Tambat
(c) Raja Ravi Verma
(d) James Wales
Answer:
(a) Pestonji Bomanji.

(i) The lion capital of the Ashoka pillar found at …………………………. is the national emblem of India.
(a) Bodhgaya
(b) Patliputra
(c) Sanchi
(d) Sarnath
Answer:
(d) Sarnath

(j) The stupa at …………………………. in Indonesia is the largest stupa in the world.
(a) Ubud
(b) Sigiran
(c) Borobudur
(d) Palembang
Answer:
(c) Borobudur

(k) The …………………………. school of art laid the foundation of Indian iconography.
(a) Gandhar
(b) Nagara
(c) Dravid
(d) Mathura
Answer:
(d) Mathura

(l) The temple architecture developed in India around 4th century C.E. during the …………………………. period.
(a) Kushana
(b) Rashtrakuta
(c) Gupta
(d) Chola
Answer:
(c) Gupta

(m) …………………………. is a blend of Nagara style of architecture of North India and Dravid style of South India.
(a) Gandhar
(b) Mathura
(c) Bhoomija
(d) Vesara
Answer:
(d) Vesara.

(n) The two main branches of the Indian classical music are ………………………… .
(a) Folk music and Vocal
(b) Dadraa and Thumri
(c) Bhajans and Qawwalis
(d) Hindustani music and Carnatic music
Answer:
(d) Hindustani music and Carnatic music

(o) The text of …………………………. written by Bharatmuni is supposed to be the earliest one discussing music and theatre.
(a) Manasollas
(b) Abhilasha Chintamani
(c) Natyashastra
(d) Rasratnakar
Answer:
(c) Natyashastra

(p) Every year the …………………………. festival is held in Pune.
(a) Kala Ghoda
(b) Gunidas
(c) Savai Gandharva
(d) Gharapuri
Answer:
(c) Savai Gandharva

(q) The ruler of Bijapur, Ibrahim Adilshah wrote …………………………. text in Persian language.
(a) Tuzuk-i-Babari
(b) Padmavat
(c) Akbarnama
(d) Kitab-e-Navras
Answer:
(d) Kitab- e-Navras

(r) …………………………. is a prominent name among artists who created a new style of fusion of Indian and Western dance.
(a) Pandit Shivkumar Sharma
(b) Pandit Hariprasad Chaurasia
(c) Pandit Uday Shankar
(d) Ustad Zakir Hussain
Answer:
(a) Pandit Uday Shankar.

Question 7.
Identify the wrong pair in the following and write it:
(1)

Architectural structure	Place
(1) Kutub Minar	(a) Mehrauli
(2) Gol Gumbaz	(b) Bijapur
(3) Chhatrapati Shivaji Maharaj Railway Terminus	(c) Delhi
(4) Taj Mahal	(d) Agra

Answer:
Wrong pair: Chhatrapati Shivaji Maharaj Railway Terminus – Delhi

(2)

Picture	Style
(1) Murals seen in the old wadas at Wai, Menavali	(a) Miniature style
(2) Bhimbetka	(b) Folk painting
(3) Pictures narrating Ramayana and Mahabharata story	(c) Chitrakathi
(4) Painting style in Thane district	(d) Warli painting

Answer:
Wrong pair: Murals seen in the old wadas at Wai, Menavali – Miniature style

(3)

Architectural structure	Style
(1) Chhatrapati Shivaji Maharaj Railway Terminus	(a) Gothic architecture
(2) Gol Gumbaz	(b) Muslim architecture
(3) Temples in South India	(c) Nagara architecture
(4) Gondeshwar Temple	(d) Hemadpanti architecture

Answer:
Wrong pair: Temples in South India – Nagara architecture

(4)

Monument	Emperors
(1) Completed Kutub Minar	(a) Altmash
(2) Construction of Taj Mahal	(b) Emperor Akbar
(3) Gol Gumbaz	(c) Mohammed Adilshah
(4) Built Sanchi Stupa	(d) Emperor Ashoka

Answer:
Wrong pair: Construction of Taj Mahal – Emperor Akbar

Question 3.
Do as directed:
(A) Complete the following concept chart:
(1)

Answer:

(2)

Answer:

(3)

Answer:

(4)

Answer:

(5)

Answer:

(6)

Answer:

(B) Prepare a flow chart on the Development of Indian Iconography.
Answer:

Question 8.
Explain the following concepts:
(a) Style in Art:
Answer:

• Every artist has its own method of working which becomes his style.
• When this style is repeated by several artists over a prolonged period of time it becomes a tradition.
• This tradition is known as an art ‘style’.
• Such traditions are established in every art style. Various art styles are developed over the years in every culture.
• The specific art styles indicate the characteristic of a certain region and period.
• They help us to learn the history of arts of these civilizations.

(b) Classical Style of Paintings:
Answer:

• Art which is expressed within an established frame of consistent rules is known as classical art. The ancient Indian texts mentioned altogether 64 arts.
• The aft of painting is mentioned as alekhyam or alekhya vidya in these texts.
• This alekhya vidya has six main aspects of paintings (Shadange).
• They are shapes and forms (Roopbheda), expressions (Bhava).
• Proportionate depiction of various features of an image (Pramana).
• Aesthetics (Lavanyayojana), resemblance to reality (Sadrushyata) and colour composition (Varnikabhang).
• Agama text of Jainism and in Puranas various arts like painting, sculpting are explained in context of temple architecture.

Question 9.
Write short notes:
(a) Chitrakathi:
Answer:

1. The tradition of narrating stones from Ramayana and Mahabharata with the help of wooden puppets and paintings is known as Chitrakathi. It is also known as Pinguli.
2. This tradition is mentioned in Manasollas, a book written by the Chalukya King Someshvara in the 12th century. People belonging to Thakur community stifi practise this art They are frm village, Pinguli near Kudal in Maharashtra.
3. The Chitrakathi pictures are drawn on paper and painted with natural substances. To complete the narration of a single story it takes around 30 to 50 pictures.
4. These pictures are preserved and are passed on from one generation to another. The artists and government are trying to preserve this tradition which is on the verge of extinction.

(b) Miniature Painting:
Answer:

• Painting in a small size square is called Miniature painting.
• The miniature reached people through manuscripts. The earlier period of miniature painting shows the influence of Persian style.
• The Deccan miniature style was developed under the patronage of the Deccan Sultanate.
• Mughal miniature painting style of painting’ was developed during the reign of Mughal Emperor Akbar. ¡t shows a blend of Indian and Persian style.

(c) Western style of painting:
Answer:

• Indian artists came under the influence of European style of painting during the British period.
• An art school at Shaniwar Wada at Pune was established under the leadership of Scottish artist James Wales.
• J. J. School of art and industry was established in 1857 to offer the courses in European style of painting.
• Pestonji Bomanji made replicas of Ajanta paintings.
• lames Wales had done a portrait of Savai Madhavrao and Nana Phadnavis.
• Exact portrayal of the object of the painting is a characteristic of European style.

(d) Gangaram Tambat:
Answer:

• An art school was established under the leadership of Scottish artist James Wales at Shanivar Wada in Pune.
• Marathi artist Gangaram Tambat worked with James Wales.
• He made drawings of rock-cut caves at Verul and Karle.
• Some of his drawings are preserved in the Yale Centre of British Art of Yale University.

(e) Temple architecture:
Answer:

1. Temple architecture began to develop in India around 4th century C.E. during the Gupta period. In the initial stage of the Gupta period, the temples had only the Sanctum Sanctorum (Garbhagriha) and a Veranda with four columns.
2. Temple architecture reached its peak by the 8th century C. E. and its example is the Kailas temple of Verul. By medieval period various types of temple architecture had developed in India.
3. The styles of tower (Shikar) determined various styles of temple architecture in India. The Nagara style of North India and Dravid style of South India are two prominent styles of Indian temple architecture. A blend of Nagara and Dravid is known as Vesara style.
4. Bhoomija style seen in temples of Maharashtra and Madhya Pradesh has very close resemblance to ‘Nagara’ style.

(f) Indo-Gothic Architecture:
Answer:

1. During the British period, a new architectural style arose in India which was a blend of Indian and Gothic known as Indo-Gothic style of architecture.
2. During the British period, buildings like churches, government offices, residences of top officials, railway stations were built in Indo-Gothic style of architecture.
3. Chhatrapati Shivaji Maharaj Railway Terminus in Mumbai is the finest example of Indo- Gothic style of architecture.

(g) Ttitab-e-Navras:
Answer:

1. Ibrahim Adilshah II, the ruler of Bijapur, wrote a book in Persian language entitled ‘Kitab- e-Navras’. This text is about Indian classical music.
2. It includes the verses suitable for singing. It is a composition of excellent poetry expressed through Dhrupad style giving the experience of ecstasy to the interested audience.
3. The Ncrvras mentioned in Sanskrit literature are explained in this text.

Question 10.
Explain the following sentences with reasons:
(a) Indian performing arts were enriched over time.
Answer:

• A constant stream of rulers like the Greeks, Arabs, Mughals and the British came to India.
• During their rule, Indian people came into contact with their styles of folk art.
• The culture which they brought along lasted and blended with existing streams of Indian performing arts.
• As a result, many styles of classical vocal music, instrumental music and dance came into existence.
• Therefore Indian performing arts enriched over time.

(b) The field of Applied Arts needs professionals.
Answer:

• An artistic creation is combined with utilitarian purpose to make it economically viable in applied arts.
• Many stages of production are reached before the concept of creation becomes a reality.
• Each field in applied arts requires detailed planning and meticulous management at each stage of production.
• Ornaments, earthen pots with colourful designs, objects made from Cane and Bamboo, beautiful glass objects.
• Attractive textiles and clothing all listed under applied arts essentially require trained and skilled individuals at every stage.
• Some of the production processes of artistic objects have a history of certain traditions. It is important to have knowledge of those traditions.

Hence, it is essential to have trained and skilled professionals at every stage.

Question 11.
Answer the following question in 25-30 words:
(a) Write about follk traditions of sculptural art.
Answer:

• The tradition of folk art dates back to the Stone Ages.
• The custom of making clay images for rituals has been prevalent in India since Harappcin times.
• It has continued even today in many regions of Bengal, Bihar, Gujarat and Rajasthan.
• During the festivals, Ganesh idols are made along with the masks of Goddess Gauri.
• Bull figurines are made for the festival of Bailpola.
• Wooden memorials, Veergals (memorial stones), the decorated clay storage bins, etc.
• Are examples of folk tradition of sculptural art.
• The sculptures made for religious and festival reasons became masterpieces of artists’ creation.

(b) Write about Gandhara School of Art.
Answer:

• The regions around Afghanistan showed great influence of Greeks and Persians from 2nd century B.C.E.
• Gandhara style of art was a fusion of Greek- Roman and Indian style.
• Gandhara school was heavily influenced by Greek methodologies.
• The materials used to make sculptures were Grey sandstone. Mud, Lime and Stucco.
• Grey sandstone is more prominently used in Gandhara School of Art.
• The Gandhara school images are known for their anatomical accuracy, spatial depth and foreshortening.
• The sculptures in Gandhara style are found in Taxila, Peshawar and on the North West Frontier.

(c) Write about development of Indian Iconography.
Answer:

• The Kushana period from the 1st – 3rd century C.E. saw the rise of Mathura School of Art.
• The Mathura School of Art laid the foundation of Indian iconography style.
• The Kushana Kings made use of images of various deities on their coins.
• During the Gupta period, the ieonographic rules were formulated and standards for sculptural- art were set.
• The art of making bronze images was developed under the patronage of Chola Kings during 9th-13tji century.
• Bronze idols of gods and goddesses like Siva-Parvati, Natraj, Lakshmi, Vishnu, etc. were made.

(d) Give information about the rock-cut caves in India.
Answer:

• The tradition of rock-cut caves originated in India in the 3rd century B.C.E.
• The entire composition of a rock-cut cave represents a union of architecture and sculptural art.
• The entrances of such rock-cut caves, interiors with its carved columns and images are excellent specimens of sculptural art.
• The paintings on the walls and ceilings have survived till today.
• The rock-cut caves at Ajanta and Verul in Maharashtra were declared as World Heritage Sites in 1983.

(e) Elaborate on the development of temple architecture.
Answer:

• The temple architecture began to develop in India during the Gupta period in 4th century C.E.
• The temples built at the beginning of the Gupta period had only the sanctum sanctorum (Garbhagriha) and a veranda with four columns.
• The magnificent structure of the Kailas temple of Verul gives testimony that temple architecture had reached its peak by the 8th century C.E.
• Different styles of temple architecture were developed by the medieval period. Some of them are Nagara, Dravid, Vesara and Bhoomija.

(f) What efforts were taken in India to make dance and classical music easily accessible to common people?
Answer:
The following efforts were taken to make dance and music easily accessible to people:

• Dance programmes and musical festivals were organised at various places.
• Many people attend these festivals including Indians and foreigners.
• The Savai Gandharva festival of Pune is very famous.

(g) Write about the work of Pandit Uday Shankar.
Answer:

• Pandit Uday .Shankar created a fusion of Indian classical dance and European operti.
• New styles of dancing were developed.
• He also included various folk dances in his style of fusion.

Thus, the scope of Indian performing arts seems to be constantly expanding.

(h) Which fields are related to applied arts ?
Answer:

1. An artistic creation with a utilitarian purpose is called applied arts. Industry and advertisement. Interior Design and production of ornamental objects, Art Design of stage backdrops, Art Direction for films and television are the fields of applied arts.
2. Layout of books, magazines, production of greeting cards, invitation cards, gift objects, calligraphy are also related to applied arts.
3. Still and animated graphics, created with the help of computers are used for various purposes. This field needs experts with technical knowledge.
4. In short, whichever art is known and is applied to create something new becomes applied art.

Question 12.
Read the following passage and answer the questions:
(a) In which states of India are the sites of rock paintings found?
Answer:
The sites of rock paintings are found in the states of Madhya Pradesh, Uttar Pradesh, Bihar, Uttarakhand, Karnataka, Andhra Pradesh and Telangana.

(b) How old is the tradition of rock paintings?
Answer:
The tradition of rock painting dates back to the Stone Age.

(c) What are the features of rock paintings?
Answer:

• Rock paintings depict humans, animals, geometric figures, flora and fauna in various figures and also in colour.
• Natural colours in black and fed are used in them which are extracted from natural substances.
• The style of rock paintings seems to be changing according to the cultural changes from Stone Age to the beginning of agriculture.
• We get to know about ancient people, their natural surroundings and also the way they exploited available natural resources.

Question 13.
Answer the following questions in detail:

(a) Give information on Indian classical sculptural art.
Answer:
The development of folk styles of sculptural art led to the formation of rules for classical sculptural art and it evolved.

1. The folk style of sculpture-making began during the Harappan period. Seals, stones and bronze statues that were made, gives a testimony that the art of sculpture was known to the Indians.
2. It is about 5000 years old or even older tradition.
3. The tradition of the erected stupa started in the times of Ashoka. The stupa at Borobudur in Indonesia is the largest stupa in the world.
4. Gandhara style of sculptural art came to being in the 2nd century B.C.E. and has Greek and Persian influences.
5. During the Kushana reign, Mathura School of art evolved which was a blend of Gandhara School of Art and indigenous art.
6. The rules of Indian iconography was laid during the rule of the Gupta empire. Thus, Indian sculptural tradition has developed into a rich classical sculptural art.

(b) Differentiate between Classical and Folk: art.:
Answer:
Some differences are noted between Classical and Folk art. They are as follows: Classical Art Folk Art

Classical Art	Folk Art
1. Classical art does not have such a long tradition.	1. The tradition of folk art has continued from the prehistoric times.
2. Classical art is not connected to everyday life.	2. Folk art is an integral part of everyday life.
3. It takes a very long time period to master classical art.	3. The creation of folk art has taken place naturally because of people’s involvement.
4. Classical art developed within the established frame of rules.	4. Folk art developed as an integral part of the religious festivals and social life.
5. As classical art follows set rules, different types of styles, methods and schools are developed.	5. Folk art is not bound by any rules.

Brain Teaser

Across:

• Temples built in Maharashtra in 12-13th centuries in this style
• The text written by the ruler of Bijapur, Ibrahim Adilshah II
• Artist who created a fusion of Indian classical dance and European opera
• His drawings are preserved in the Yale Centre of British Art of Yale University

Down:

• The temple of Kailas at Verul
• An art school was established under his leadership in the times of Savai Madhavrao Peshwe
• The art of painting is mentioned as … in ancient Indian text
• Murals of Maratha style of painting can be seen at this place

Balbharti Maharashtra State Board Class 10 Maths Solutions covers the Problem Set 5 Geometry 10th Class Maths Part 2 Answers Solutions Chapter 5 Co-ordinate Geometry.

10th Standard Maths 2 Problem Set 5 Chapter 5 Co-ordinate Geometry Textbook Answers Maharashtra Board

Class 10 Maths Part 2 Problem Set 5 Chapter 5 Co-ordinate Geometry Questions With Answers Maharashtra Board

Question 1.
Fill in the blanks using correct alternatives.

i. Seg AB is parallel to Y-axis and co-ordinates of point A are (1, 3), then co-ordinates of point B can be _______.
(A) (3,1)
(B) (5,3)
(C) (3,0)
(D) (1,-3)
Answer: (D)
Since, seg AB || Y-axis.
∴ x co-ordinate of all points on seg AB
will be the same,
x co-ordinate of A (1, 3) = 1
x co-ordinate of B (1, – 3) = 1
∴ Option (D) is correct.

ii. Out of the following, point lies to the right of the origin on X-axis.
(A) (-2,0)
(B) (0,2)
(C) (2,3)
(D) (2,0)
Answer: (D)

iii. Distance of point (-3, 4) from the origin is _________.
(A) 7
(B) 1
(C) 5
(D) -5
Answer: (C)
Distance of (-3, 4) from origin
\(\begin{array}{l}{=\sqrt{(-3)^{2}+(4)^{2}}} \\ {=\sqrt{9+16}} \\ {=\sqrt{25}=5}\end{array}\)

iv. A line makes an angle of 30° with the positive direction of X-axis. So the slope of the line is ________.
(A) \(\frac { 1 }{ 2 } \)
(B) \(\frac{\sqrt{3}}{2}\)
(C) \(\frac{1}{\sqrt{3}}\)
(D) \(\sqrt { 3 }\)
Answer: (C)

Question 2.
Determine whether the given points are collinear.
i. A (0, 2), B (1, -0.5), C (2, -3)
ii. P(1,2), Q(2,\(\frac { 8 }{ 5 } \)),R(3,\(\frac { 6 }{ 5 } \))
iii L (1, 2), M (5, 3), N (8, 6)
Solution:

∴ slope of line AB = slope of line BC
∴ line AB || line BC
Also, point B is common to both the lines.
∴ Both lines are the same.
∴ Points A, B and C are collinear.

∴ slope of line PQ = slope of line QR
∴ line PQ || line QR
Also, point Q is common to both the lines.
∴ Both lines are the same.
∴ Points P, Q and R are collinear.

∴ slope of line LM ≠ slope of line MN
∴ Points L, M and N are not collinear.
[Note: Students can solve the above problems by using distance formula.]

Question 3.
Find the co-ordinates of the midpoint of the line segment joining P (0,6) and Q (12,20).
Solution:
P(x₁,y₁) = P (0, 6), Q(x₂, y₂) = Q (12, 20)
Here, x₁ = 0, y₁ = 6, x₂ = 12, y₂ = 20
∴ Co-ordinates of the midpoint of seg PQ

∴ The co-ordinates of the midpoint of seg PQ are (6,13).

Question 4.
Find the ratio in which the line segment joining the points A (3, 8) and B (-9, 3) is divided by the Y-axis.
Solution:
Let C be a point on Y-axis which divides seg AB in the ratio m : n.
Point C lies on the Y-axis
∴ its x co-ordinate is 0.
Let C = (0, y)
Here A (x₁,y₁) = A(3, 8)
B (x₂, y₂) = B (-9, 3)
∴ By section formula,


∴ Y-axis divides the seg AB in the ratio 1 : 3.

Question 5.
Find the point on X-axis which is equidistant from P (2, -5) and Q (-2,9).
Solution:
Let point R be on the X-axis which is equidistant from points P and Q.
Point R lies on X-axis.
∴ its y co-ordinate is 0.
Let R = (x, 0)
R is equidistant from points P and Q.
∴ PR = QR

∴ (x – 2)² + [0 – (-5)]² = [x – (- 2)]² + (0 – 9)² …[Squaring both sides]
∴ (x – 2)² + (5)² = (x + 2)² + (-9)²
∴ 4 – 4x + x² + 25 = 4 + 4x + x² + 81
∴ – 8x = 56
∴ x = -7
∴ The point on X-axis which is equidistant from points P and Q is (-7,0).

Question 6.
Find the distances between the following points.
i. A (a, 0), B (0, a)
ii. P (-6, -3), Q (-1, 9)
iii. R (-3a, a), S (a, -2a)
Solution:
i. Let A (x₁, y₁) and B (x₂, y₂) be the given points.
∴ x₁ = a, y₁ = 0, x₂ = 0, y₂ = a
By distance formula,

∴ d(A, B) = a\(\sqrt { 2 }\) units

ii. Let P (x₁, y₁) and Q (x₂, y₂) be the given points.
∴ x₁ = -6, y₁ = -3, x₂ = -1, y₂ = 9
By distance formula,

∴ d(P, Q) = 13 units

iii. Let R (x₁, y₁) and S (x₂, y₂) be the given points.
∴ x₁ = -3a, y₁ = a, x₂ = a, y₂ = -2a
By distance formula,

∴ d(R, S) = 5a units

Question 7.
Find the co-ordinates of the circumcentre of a triangle whose vertices are (-3,1), (0, -2) and (1,3).
Solution:
Let A (-3, 1), B (0, -2) and C (1, 3) be the vertices of the triangle.
Suppose O (h, k) is the circumcentre of ∆ABC.

∴ (h + 3)² + (k – 1)² = h² + (k + 2)²
∴ h² + 6h + 9 + k² – 2k + 1 = h² + k² + 4k + 4
∴ 6h – 2k + 10 = 4k + 4
∴ 6h – 2k – 4k = 4 – 10
∴ 6h – 6k = – 6
∴ h – k = -1 ,..(i)[Dividing both sides by 6]
OB = OC …[Radii of the same circle]

∴ h² + (k + 2)² = (h – 1)² + (k – 3)²
∴ h² + k² + 4k + 4 = h² – 2h + 1 + k² – 6k + 9
∴ 4k + 4 = -2h + 1 – 6k + 9
∴ 2h+ 10k = 6
∴ h + 5k = 3 …(ii)
Subtracting equation (ii) from (i), we get

∴ The co-ordinates of the circumcentre of the triangle are (\(\frac { -1 }{ 3 } \),\(\frac { 2 }{ 3 } \))

Question 8.
In the following examples, can the segment joining the given points form a triangle? If triangle is formed, state the type of the triangle considering sides of the triangle.
i. L (6, 4), M (-5, -3), N (-6, 8)
ii. P (-2, -6), Q (-4, -2), R (-5, 0)
iii. A(\(\sqrt { 2 }\),\(\sqrt { 2 }\)),B(-\(\sqrt { 2 }\),-\(\sqrt { 2 }\)),C(\(\sqrt { 6 }\),\(\sqrt { 6 }\))
Solution:
i. By distance formula,

∴ d(M, N) + d (L, N) > d (L, M)
∴ Points L, M, N are non collinear points.
We can construct a triangle through 3 non collinear points.
∴ The segment joining the given points form a triangle.
Since MN ≠ LN ≠ LM
∴ ∆LMN is a scalene triangle.
∴ The segments joining the points L, M and N will form a scalene triangle.

ii. By distance formula,


∴ d(P, Q) + d(Q, R) = d (P, R) …[From (iii)]
∴ Points P, Q, R are collinear points.
We cannot construct a triangle through 3 collinear points.
∴ The segments joining the points P, Q and R will not form a triangle.

iii. By distance formula,

∴ d(A, B) + d(B, C) + d(A, C) … [From (iii)]
∴ Points A, B, C are non collinear points.
We can construct a triangle through 3 non collinear points.
∴ The segment joining the given points form a triangle.
Since, AB = BC = AC
∴ ∆ABC is an equilateral triangle.
∴ The segments joining the points A, B and C will form an equilateral triangle.

Question 9.
Find k, if the line passing through points P (-12, -3) and Q (4, k) has slope \(\frac { 1 }{ 2 } \).
Solution:
P(x₁,y₁) = P(-12,-3),
Q(X₂,T₂) = Q(4, k)
Here, x₁ = -12, x₂ = 4, y₁ = -3, y₂ = k

But, slope of line PQ (m) is \(\frac { 1 }{ 2 } \) ….[Given]
∴ \(\frac { 1 }{ 2 } \) = \(\frac { k+3 }{ 16 } \)
∴ \(\frac { 16 }{ 2 } \) = k + 3
∴ 8 = k + 3
∴ k = 5
The value of k is 5.

Question 10.
Show that the line joining the points A (4,8) and B (5, 5) is parallel to the line joining the points C (2, 4) and D (1 ,7).
Proof:

∴ Slope of line AB = Slope of line CD
Parallel lines have equal slope.
∴ line AB || line CD

Question 11.
Show that points P (1, -2), Q (5, 2), R (3, -1), S (-1, -5) are the vertices of a parallelogram.
Proof:
By distance formula,

In ꠸PQRS,
PQ = RS … [From (i) and (iii)]
QR = PS … [From (ii) and (iv)]
∴ ꠸ PQRS is a parallelogram.
[A quadrilateral is a parallelogram, if both the pairs of its opposite sides are congruent]
∴ Points P, Q, R and S are the vertices of a parallelogram.

Question 12.
Show that the ꠸PQRS formed by P (2, 1), Q (-1, 3), R (-5, -3) and S (-2, -5) is a rectangle.
Proof:
By distance formula,


In ꠸PQRS,
PQ = RS …[From (i) and (iii)]
QR = PS …[From (ii) and (iv)]
꠸PQRS is a parallelogram.
[A quadrilateral is a parallelogram, if both the pairs of its opposite sides are congruent]

In parallelogram PQRS,
PR = QS … [From (v) and (vi)]
∴ ꠸PQRS is a rectangle.
[A parallelogram is a rectangle if its diagonals are equal]

Question 13.
Find the lengths of the medians of a triangle whose vertices are A (-1, 1), B (5, -3) and C (3,5).
Solution:

Suppose AD, BE and CF are the medians.
∴ Points D, E and F are the midpoints of sides BC, AC and AB respectively.
∴ By midpoint formula,


∴ The lengths of the medians of the triangle 5 units, 2\(\sqrt { 13 }\) units and \(\sqrt { 37 }\) units.

Question 14.
Find the co-ordinates of centroid of the triangle if points D (-7, 6), E (8, 5) and F (2, -2) are the mid points of the sides of that triangle.
Solution:

Suppose A (x₁, y₁), B (x₂, y₂) and C (x₃, y₃) are the vertices of the triangle.
D (-7, 6), E (8, 5) and F (2, -2) are the midpoints of sides BC, AC and AB respectively.
Let G be the centroid of ∆ABC.
D is the midpoint of seg BC.
By midpoint formula,

E is the midpoint of seg AC.
By midpoint formula,

Adding (i), (iii) and (v),
x₂ + x₃ + x₁ + x₃ + x₁ + x₂ = -14 + 16 + 4
∴ 2x₁ + 2x₂ + 2x₃ = 6
∴ x₁ + x₂ + x₃ = 3 …(vii)
Adding (ii), (iv) and (vi),
y₂ + y₃ + y₁ + y₃ + y₁ +y₂ = 12 + 10 – 4
∴ 2y₁ + 2y₂ + 2y₃ = 18
∴ y₁ + y₂ + y₃ = 9 …(viii)
G is the centroid of ∆ABC.
By centroid formula,

∴ The co-ordinates of the centroid of the triangle are (1,3).

Question 15.
Show that A (4, -1), B (6, 0), C (7, -2) and D (5, -3) are vertices of a square.
Proof:
By distance formula,


∴ □ABCD is a square.
[A rhombus is a square if its diagonals are equal]

Question 16.
Find the co-ordinates of circumcentre and radius of circumcircle of AABC if A (7, 1), B (3,5) and C (2,0) are given.
Solution:
Suppose, O (h, k) is the circumcentre of ∆ABC


∴ h² – 6h + 9 + k² – 10k + 25 = h² – 4h + 4 + k²
∴ 2h + 10k = 30
∴ h + 5k = 15 … (ii)[Dividing both sides by 2]
Multiplying equation (i) by 5, we get
25h + 5k = 115 …(iii)
Subtracting equation (ii) from (iii), we get

Substituting the value of h in equation (i), we get

∴ The co-ordinates of the circumcentre of the triangle are (\(\frac { 25 }{ 6 } \),\(\frac { 13 }{ 6 } \)) and radius of circumcircle is \(\frac{13 \sqrt{2}}{6}\) units.

Question 17.
Given A (4, -3), B (8, 5). Find the co-ordinates of the point that divides segment AB in the ratio 3:1.
Solution:
Suppose point C divides seg AB in the ratio 3:1.
Here; A(x₁, y₁) = A (4, -3)
B (x₂, y₂) = B (8, 5)
By section formula,

∴ The co-ordinates of point dividing seg AB in ratio 3 : 1 are (7, 3).

Question 18.
Find the type of the quadrilateral if points A (-4, -2), B (-3, -7), C (3, -2) and D (2, 3) are joined serially.
Solution:

Slope of AB = slope of CD
∴ line AB || line CD
slope of BC = slope of AD
∴ line BC || line AD
Both the pairs of opposite sides of ∆ABCD are parallel.
∴ ꠸ ABCD is a parallelogram.
∴ The quadrilateral formed by joining the points A, B, C and D is a parallelogram.

Question 19.
The line segment AB is divided into five congruent parts at P, Q, R and S such that A-P-Q-R-S-B. If point Q (12, 14) and S (4, 18) are given, find the co-ordinates of A, P, R, B.
Solution:

Points P, Q, R and S divide seg AB in five congruent parts.
Let A (x₁, y₁), B (x₂, y₂), P (x₃, y₃) and
R (x₄, y₄) be the given points.
Point R is the midpoint of seg QS.
By midpoint formula,
x co-ordinate of R = \(\frac { 12+4 }{ 2 } \) = \(\frac { 16 }{ 2 } \) = 8
y co-ordinate of R = \(\frac { 14+18 }{ 2 } \) = \(\frac { 32 }{ 2 } \) = 16
∴ co-ordinates of R are (8, 16).
Point Q is the midpoint of seg PR.
By midpoint formula,

∴ 28 = y₃ + 16
∴ y₃ = 12
∴ P(x₃,y₃) = (16, 12)
∴ co-ordinates of P are (16, 12).
Point P is the midpoint of seg AQ.
By midpoint formula,

∴ co-ordinates of A are (20, 10).
Point S is the midpoint of seg RB.
By midpoint formula,

∴ 36 = y₂ + 16
∴ y₂ = 20
∴ B(x₂, y₂) = (0, 20)
∴ co-ordinates of B are (0, 20).
∴ The co-ordinates of points A, P, R and B are (20, 10), (16, 12), (8, 16) and (0, 20) respectively.

Question 20.
Find the co-ordinates of the centre of the circle passing through the points P (6, -6), Q (3, -7) and R (3,3).
Solution:
Suppose O (h, k) is the centre of the circle passing through the points P, Q and R.

∴ (h – 6)² + (k + 6)² = (h – 3)² + (k + 7)²
∴ h² – 12h + 36 + k² + 12k + 36
= h² – 6h + 9 + k² + 14k + 49
∴ 6h + 2k = 14
∴ 3h + k = 7 …(i)[Dividing both sides by 2]
OP = OR …[Radii of the same circle]

∴ (h – 6)² + (k + 6)² = (h – 3)² + (k – 3)²
∴ h² – 12h + 36 + k² + 12k + 36
= h² – 6h + 9 + k² – 6k + 9
∴ 6h – 18k = 54
∴ 3h – 9k = 27 …(ii)[Dividing both sides by 2]
Subtracting equation (ii) from (i), we get

Substituting the value of k in equation (i), we get
3h – 2 = 7
∴ 3h = 9
∴ h = \(\frac { 9 }{ 3 } \) = 3
∴ The co-ordinates of the centre of the circle are (3, -2).

Question 21.
Find the possible pairs of co-ordinates of the fourth vertex D of the parallelogram, if three of its vertices are A (5, 6), B (1, -2) and C (3, -2).
Solution:

Let the points A (5, 6), B (1, -2) and C (3, -2) be the three vertices of a parallelogram.
The fourth vertex can be point D or point Di or point D₂ as shown in the figure.
Let D(x₁,y₁), D, (x₂, y₂) and D₂ (x₃,y₃).
Consider the parallelogram ACBD.
The diagonals of a parallelogram bisect each other.
∴ midpoint of DC = midpoint of AB


Co-ordinates of point D(x₁, y₁) are (3, 6).
Consider the parallelogram ABD₁C.
The diagonals of a parallelogram bisect each other.
∴ midpoint of AD₁ = midpoint of BC

∴ Co-ordinates of D₁(x₂,y₂) are (-1,-10).
Consider the parallelogram ABCD₂.
The diagonals of a parallelogram bisect each other.
∴ midpoint of BD₂ = midpoint of AC

∴ co-ordinates of point D₂ (x₃, y₃) are (7, 6).
∴ The possible pairs of co-ordinates of the fourth vertex D of the parallelogram are (3, 6), (-1,-10) and (7,6).

Question 22.
Find the slope of the diagonals of a quadrilateral with vertices A (1, 7), B (6,3), C (0, -3) and D (-3,3).
Solution:
Suppose ABCD is the given quadrilateral.

∴ The slopes of the diagonals of the quadrilateral are 10 and 0.

Class 10 Maths Digest

• Practice Set 4.1 Class 10 Answers
• Practice Set 4.2 Class 10 Answers
• Problem Set 4 Class 10 Answers
• Practice Set 5.1 Class 10 Answers
• Practice Set 5.2 Class 10 Answers
• Practice Set 5.3 Class 10 Answers
• Problem Set 5 Class 10 Answers