NIOS Class 10 Science and Technology Chapter 24 Reproduction

NIOS Class 10 Science and Technology Chapter 24 Reproduction Solutions to each chapter is provided in the list so that you can easily browse through different chapters NIOS Class 10 Science and Technology Chapter 24 Reproduction and select need one. NIOS Class 10 Science and Technology Chapter 24 Reproduction Question Answers Download PDF. NIOS Study Material of Class 10 Science and Technology Notes Paper 212.

NIOS Class 10 Science and Technology Chapter 24 Reproduction

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Also, you can read the NIOS book online in these sections Solutions by Expert Teachers as per National Institute of Open Schooling (NIOS) Book guidelines. These solutions are part of NIOS All Subject Solutions. Here we have given NIOS Class 10 Science and Technology Chapter 24 Reproduction, NIOS Secondary Course Science and Technology Solutions for All Chapters, You can practice these here.

Reproduction

Chapter: 24

INTEXT QUESTIONS 24.1

1. Define reproduction.

Ans: Biological process by which organisms give rise to offspring of their own kind.

2. State one point of difference between asexual and sexual reproduction.

Ans: The difference between asexual and sexual reproduction are mentioned below: 

Asexual: offspring produced by single individual.

Sexua: Two individuals are involved in producing offspring.

3. Why is binary fission considered to be an asexual form of reproduction?

Ans: Cell divides to give rise to two offspring while losing its own identity.

4. Define vegetative propagation with the help of an example.

Ans: New plants may arise and grow from roots, stems or leaves. e.g. Bryophyllum.

5. Define the following:

(i) Callus.

Ans: Undifferentiated mass of cells in culture medium (callus).

(ii) Clone.

Ans: Genetic copy of the parent, e.g. Dolly – the cloned sheep.

INTEXT QUESTIONS 24.2

1. What purpose does the flower serve in a plant?

Ans: It serves as the reproductive organ of the plants.

2. Give one point of difference between self pollination and cross pollination.

Ans: The difference between self pollination and cross pollination are mentioned below: 

Self pollination:

When pollen of the same flower on the stigma and then fertilises the ovule of the same flower.

Cross pollination:

Pollen from one flower falls on falls stigma of another flower of the same species to fertilise the ovule of The latter.

3. What will happen if the pistil of the flower is removed?

Ans: Fertilisation leading to seed formation for new generation of plants will not be possible.

4. Trace the path of the pollen after it lands on the stigma.

Ans: Pollen grain forms a pollen tube and pollen grain nucleus reaches the ovule as pollen tube pushes through the pistil. The pollen nucleus fuses with the nucleus of the ovule.

5. What is germination of seed?

Ans: Fertilised ovules develop into seeds which are capable of germinating into seedlings and subsequently growing into new plants.

INTEXT QUESTIONS 24.3

1. Define the terms:

(i) Adolescence.

Ans: (i) Stage of life at the age between 11 to 19 years when physical and physiological changes take place in the body is called adolescence.

(ii) Puberty. 

Ans: The time period when changes occur that make human capable of reproduction.

(iii) Hermaphrodite.

Ans: Both male and female sex organs are in the same individual.

(iv) Oviparous. 

Ans: Development of an embryo may occur up to an extent or up to completion inside the egg.

(v) Viviparous. 

Ans: Baby develops inside the mother’s womb/ giving birth to young ones.

(vi) Foetus.

Ans: Developing embryo implanted in the uterus wall of the mother. 

2. Name the hormones secreted by the testes and ovary.

Ans: Testosterone and oestrogen.

3. Name the part of the female reproductive system where the egg gets fertilised by the sperm.

Ans: Developing embryo.

4. State the function of

(i) Uterus.

Ans: Embryo develops inside uterus.

(ii) Vas deferens.

Ans: Sperms pass through these into ejaculatory duct.

5. Consider the three case studies given below. Please provide your suggestions for managing these situations in 2-4 sentences each.

Ans:  Analysis case studies attempted by student incorporating knowledge gained on adolescence and puberty.

INTEXT QUESTIONS 24.4

1. List, in a sequence the events that lead to the birth of a new individual.

Ans: Human sperm and Human ovum “formation of zygote “ developing embryo” foetus in the uterus “born after development is complete”.

2. Name the hormones responsible, for attaining reproductive maturity, and for formation and maturing of sperms and eggs in humans.

Ans: FSH and LH.

3. Given below is a list of hormones related to reproduction. List influence on functions in the space given below:

FSH, LH, Oestrogen, Testosterone, Oxytocin.

Ans: 

INTEXT QUESTIONS 24.5

1. Name any four sexually transmitted diseases.

Ans: Syphilis, Gonorrhea, herpes, Chlamydia.

2. Name four devices which prevent fertilisation in humans.

Ans: IUCD – Copper T, Oral contraceptive pills, vasectomy in male/tubectomy in female, MTP.

3. Expand the abbreviations:

(i) HIV.

Ans: HIV – Human Immunodeficiency virus.

(ii) AIDS.

Ans: AIDS – Acquired Immuno Deficiency Syndrome.

1. Name the biological process by virtue of which a species continues from generation to generation?

Ans: Reproduction enables the continuity of the species generation after generation. Reason: Reproduction is a biological process in which an organism gives rise to young ones similar to itself.

2. Mention two differences between asexual and sexual modes of reproduction?

Ans: Two differences between asexual and sexual modes of reproduction are mentioned below: 

3. Mention an example for each of the following methods of reproduction.

(i) Budding. 

Ans: Hydra follow the budding methods for reproduction.

(ii) Spore formation. 

Ans: The cytoplasm and nucleus of algae such as Chlamydomonas divide successively to form 4 to 8 spores.

(iii) Binary fission. 

Ans: Binary fission: amoeba.

(iv) Vegetative reproduction.

Ans: bryophyllum follows the method of vegetative reproduction.

4. Why is vegetative reproduction considered as a type of asexual reproduction?

Ans: Vegetative reproduction is considered asexual reproduction because, in this biological process, the vegetative part of the parent plants (root, stem, leaf etc.) are preserved and propagated to produce a new individual. It does not involve the fusion of gametes. The offspring are produced by a single parent.

5. Mention the specialised parts that are responsible for vegetative mode of reproduction in the following plants. 

(i) Ginger.

(ii) Grass. 

(iii) Onion.

(iv) Potato. 

Ans: (i) Ginger,by rhizomes, grass by stolon, Onion by bulb, potato by steam.

6. How is artificial vegetative propagation different from natural vegetative propagation? How is the former beneficial to humans?

Ans: Vegetative Propagation: In nature, new plants may arise from root, stem or leaves that are from the vegetative parts of the plant as. This form of asexual reproduction in plants is termed vegetative propagation.

since it improves the quality, yield, and disease resistance of plants and, consequently, plant products. As a result, this technique is economically viable.

7. How is a callus developed in tissue culture? Give the steps.

Ans: In order to grow a callus in plant tissue culture, a piece of the explant’s plant tissue should be placed on a nutritive medium. In order to revive a plant, these callus need to be transferred to a fresh medium. A callus culture consists of three steps: induction, proliferation, and differentiation.

The steps are: 

(i) A little piece of plant tissue is extracted from the plant’s growth point or tip and placed on a sterile jelly containing nutrients and plant hormones.

(ii) Hormones cause plant tissue cells to multiply rapidly, resulting in an enormous number of cells forming a ‘callus,’ a shapeless mass of material.

(iii) The callus is subsequently submerged in a jelly containing plant hormones that encourage rooting.

(iv)The callus with roots is then placed on a jelly containing several hormones that aid in the development of new shoots.

(v) The callus develops into small plantlets with roots and branches. Using this method, a few initial plant cells or tissue are used to create a large number of miniature plantlets.

8. Why is it said that all living cells are totipotent? Explain.

Ans: The ability of a living cell to divide and produce all the differentiated cells in an organism is called totipotency. A single cell divides and forms a whole new organism. Plant cells have the ability to divide and form a new organism.

9. Label the following parts in the given diagram. 

(i) part that produces pollen. 

(ii) part of the flower that receives the pollen. 

(iii) part that contains ovules. 

(iv) the part of the flower that holds the anther. 

Ans: 

10. Justify the following statements: 

(i) Birds, reptiles and frogs are called ‘Oviparous’. 

Ans: Birds, reptiles and frogs are called oviparous because their mode of reproduction is by hatching of eggs and thus not going through development of embryo internally.

(ii) Humans are ‘Viviparous’. 

Ans: Viviparous animals are those in which fertilisation and embryo development occur inside the individual. Humans are viviparous. Mammals such as cows, monkeys, chimpanzees are viviparous.

(iii) Earthworm is a ‘hermaphrodite’. 

Ans: Earthworms are hermaphrodites, meaning an individual worm has both male and female reproductive organs. Earthworm mating typically occurs after it has rained and the ground is wet.

(iv) The sheep ‘Dolly’ was a clone of her mother.

Ans: Dolly was cloned from a mammary gland cell taken from an adult Finn Dorset ewe. Wilmut and his team of researchers at Roslin created her by using electrical pulses to fuse the mammary cell with an unfertilized egg cell, the nucleus of which had been removed.

11. Trace the events after pollination that lead to seed formation.

Ans: The pistil of the flower helps to make the seeds in the flowers as when the pollen is strictly in the ovary of the flower then after pollination the seed is formed. The pollen grain travels along the pollen tube and fertilises the nucleus in the ovule. The fertilised ovule develops into a seed. The plant embryo is contained in the seed, which carries genetic material from both parents. The ovary gives rise to the fruit.

12. Identify (a) (b) (c) and (d) in the following table.

Ans: 

13. List the physiological changes that arise at puberty in

(i) Human female.

Ans: Puberty is associated with emotional and hormonal changes, as well as physical changes such as breast development in females (thelarche).

(ii) Human male.

Ans: Pubic hair development (pubarche), genital changes in males, voice changes, an increase in height, and the onset of menstruation (menarche).

14. Mention the psychological changes that are experienced by the adolescents.

Ans: During adolescence young people will negotiate puberty and the completion of growth, take on sexually dimorphic body shape, develop new cognitive skills (including abstract thinking capacities), develop a clearer sense of personal and sexual identity, and develop a degree of emotional, personal, and financial.

15. Mention the fate of the thickened uterine lining in human of in case fertilisation does not occur.

Ans: Thickening of the lining of the uterus is a sign that the “laying” is ready for a fertilised egg to implant during each menstrual cycle. If fertilisation does not occur, this mucosal layer will be peeled off and pushed out of the body, causing menstruation in women.

16. Do you agree with the statement “A strong force of one billion Indians can achieve all the developmental goals and lot more”? Why/Why not?

Ans:  As today ‘s world the manpower is the strength of that country which set an example by the Chinese in different field so India also takes this as an opportunity not as a burden to develop.

17. Why is it that.

(i) Women acquire STIs more easily as compared to men? 

Ans: A woman’s urogenital anatomy is more exposed and vulnerable to STIs compared with the male urogenital anatomy, particularly because the vaginal mucosa is thin, delicate and easily penetrated by infectious agents⁵.

(ii) Young women are more susceptible to acquire STIs as compared to men? 

Ans: Larger mucosal surface area, microlesions caused during sex (particularly forced sex), and the presence of more HIV in semen than in vaginal secretions all contribute to women’s greater vulnerability to STDs and HIV. Their sex partners’ behaviours also put women at risk for STDs and HIV.