Science Class- 10
Class 10 - Chapter 7: How do Organisms Reproduce?
Q1. Asexual reproduction takes place through budding in
Answer: (b) Yeast.
Yeast reproduces asexually by budding, in which a small outgrowth develops on the parent body and eventually separates to form a new individual.
Q2. Which of the following is not a part of the female reproductive system in human beings?
Answer: (c) Vas deferens.
Vas deferens is a part of the male reproductive system and carries sperms from the testes.
Q3. The anther contains
Answer: (d) Pollen grains.
Anthers are the male reproductive parts of a flower and produce pollen grains containing male gametes.
Q4. What are the advantages of sexual reproduction over asexual reproduction?
Advantages of Sexual Reproduction:
- Produces genetic variations among offspring.
- Variations help organisms adapt to changing environments.
- Increases chances of survival of species.
- Promotes evolution and formation of new species.
Q5. What are the functions performed by the testis in human beings?
The testes perform two main functions:
- Production of male gametes (sperms).
- Secretion of the male hormone testosterone.
Testosterone controls the development of male reproductive organs and secondary sexual characteristics.
Q6. Why does menstruation occur?
Every month, the uterus prepares itself for pregnancy by developing a thick lining.
If fertilization does not occur, the uterine lining breaks down and is expelled from the body along with blood and mucus.
This process is called menstruation.
Q7. Draw a labelled diagram of the longitudinal section of a flower.
Q8. What are the different methods of contraception?
Methods of Contraception:
- Barrier Methods: Condoms, diaphragms.
- Chemical Methods: Oral contraceptive pills.
- Intrauterine Devices (IUDs): Copper-T.
- Surgical Methods: Vasectomy and tubectomy.
- Natural Methods: Periodic abstinence.
Q9. How are the modes of reproduction different in unicellular and multicellular organisms?
| Unicellular Organisms | Multicellular Organisms |
|---|---|
| A single cell performs all life processes. | Different organs perform different functions. |
| Mostly reproduce by asexual methods such as binary fission and budding. | Commonly reproduce sexually, though some may reproduce asexually. |
| Reproduction is comparatively simple. | Reproduction involves specialized reproductive organs. |
Q10. How does reproduction help in providing stability to populations of species?
Reproduction produces new individuals of the same species.
It helps replace organisms that die and maintains the population size.
Variations produced during reproduction increase the ability of a species to survive environmental changes.
Thus, reproduction ensures continuity and stability of species.
Q11. What could be the reasons for adopting contraceptive methods?
Reasons for adopting contraception:
- To avoid unwanted pregnancies.
- To plan the number and spacing of children.
- To maintain the health of the mother and child.
- To control population growth.
- To prevent sexually transmitted diseases (STDs), especially by using condoms.