How Do Organisms Reproduce

1. Why is reproduction important for organisms?

Reproduction is important because it ensures the continuity of a species. Without reproduction, organisms would die out and the species would become extinct.

2. What is asexual reproduction?

Asexual reproduction is a type of reproduction in which only one parent is involved and the offspring produced are genetically identical to the parent.

3. What are the different methods of asexual reproduction?

Common methods are:

• Binary fission (e.g., Amoeba)

• Multiple fission (e.g., Plasmodium)

• Budding (e.g., Hydra, yeast)

• Fragmentation (e.g., Spirogyra)

• Regeneration (e.g., Planaria, starfish)

• Vegetative propagation (e.g., potato, rose, money plant)

• Spore formation (e.g., fungi)

4. What is sexual reproduction?

Sexual reproduction involves two parents (male and female) and the formation and fusion of gametes (sperm and egg). It produces genetically different offspring.

5. Why is variation important in organisms?

Variations help organisms adapt to changes in the environment. They increase the chances of survival, especially during environmental changes or diseases.

6. What is the role of DNA in reproduction?

DNA carries hereditary information. When organisms reproduce, DNA is copied and passed on to the next generation, ensuring that offspring resemble their parents.

7. What is puberty?

Puberty is the stage when the body becomes sexually mature and is capable of reproduction. It is marked by hormonal changes.

8. What changes occur in boys and girls during puberty?

Boys: voice deepens, facial hair, increased height, development of testes and sperm.
Girls: development of breasts, widening of hips, onset of menstruation, development of ovaries and eggs.

9. What is fertilisation?

Fertilisation is the fusion of a male gamete (sperm) and a female gamete (egg) to form a zygote.

10. Where does fertilisation occur in human beings?

Fertilisation occurs in the fallopian tube (oviduct).

11. What is menstruation?

Menstruation is the monthly shedding of the uterine lining along with blood through the vagina when fertilisation does not occur.

12. What is the menstrual cycle?

The menstrual cycle is a 28-day cycle of changes in the female reproductive system that prepares the body for pregnancy.

13. What is the function of the placenta?

Placenta helps in the exchange of nutrients, oxygen, and waste products between the mother and the developing embryo.

14. What are contraceptive methods?

Contraceptive methods prevent pregnancy. They include:

• Barrier methods (condoms)

• Chemical methods (pills)

• Intrauterine devices (IUDs)

• Surgical methods (vasectomy, tubectomy)

15. What is vegetative propagation?

Vegetative propagation is a form of asexual reproduction in plants where new plants grow from roots, stems, or leaves instead of seeds.

Examples: potato (tuber), ginger (rhizome), onion (bulb), money plant (stem cutting).

16. What are STDs? Give examples.

STDs (Sexually Transmitted Diseases) spread through sexual contact.
Examples: AIDS, syphilis, gonorrhoea, genital herpes.