NCERT Solutions – Chapter 7: How do Organisms Reproduce?

Subject: Science | Class: 10 | Chapter 7

Reproduction is a vital biological process that ensures the continuity of life on Earth. Every living organism reproduces to give rise to new individuals of its own kind, helping maintain population stability and genetic diversity. This chapter explains various modes of reproduction — both sexual and asexual — in plants, animals, and humans. Below are the solved exercises from this topic, designed to help students understand key concepts and prepare effectively for exams.

1. Asexual reproduction takes place through budding in

Answer: (b) Yeast

2. Which of the following is not a part of the female reproductive system in human beings?

Answer: (c) Vas deferens
Explanation: The vas deferens is a part of the male reproductive system, not the female.

3. The anther contains

Answer: (d) Pollen grains

4. Advantages of sexual reproduction over asexual reproduction:

Promotes genetic variation among offspring.
Helps in adaptation and evolution.
Reduces the risk of inheriting harmful traits.
Provides better chances of survival in changing environments.

5. Functions of testis in human beings:

Produces male gametes (sperms).
Secretes the male hormone testosterone.

6. Why does menstruation occur?

When fertilization does not take place, the thickened lining of the uterus (endometrium), along with the unfertilized egg and blood, is shed through the vagina. This process is called menstruation.

7. Draw a labelled diagram of the longitudinal section (L.S.) of a flower:

Labels:

Petal
Sepal
Stigma
Style
Ovary
Ovule
Filament
Anther

(You can include a clear labeled image or diagram here for better visual understanding.)

8. Different methods of contraception:

Barrier methods: Condoms, diaphragms.
Chemical methods: Spermicidal creams or foams.
Hormonal methods: Oral pills, injections, implants.
Intrauterine devices (IUDs): Copper-T.
Surgical methods: Vasectomy (male) and Tubectomy (female).

9. Difference in modes of reproduction between unicellular and multicellular organisms:

Unicellular Organisms	Multicellular Organisms
Reproduce by simple cell division (e.g., binary fission, budding).	Have specialized reproductive organs.
Usually asexual reproduction.	Can reproduce sexually or asexually.

10. How does reproduction help in providing stability to populations of species?

Reproduction maintains the number of individuals in a species and replaces older generations. This ensures population stability and ecological balance.

11. Reasons for adopting contraceptive methods:

To prevent unwanted pregnancies.
To control population growth.
To maintain proper spacing between children.
To prevent sexually transmitted diseases (STDs).
To ensure the health and well-being of families.

Conclusion

Reproduction plays a fundamental role in the survival of all species. Understanding its processes, from asexual reproduction in simple organisms to sexual reproduction in humans, helps students grasp the mechanisms that sustain life. Effective use of contraceptive methods and awareness about reproductive health further contribute to a healthy and balanced society.