Question

What is fertilization? Distinguish between external fertilization and internal fertilization?

Answer 1

Fertilization:

1. Fertilization is the fusion of the male gamete with the female gamete (egg or ovum) to form a single zygote cell.
2. The zygote formed by the process of fertilization carries crucial genetic information from both parents.
3. Fertilization is of two types: External and internal fertilization.

External fertilization:

External fertilization is a type of fertilization that takes place outside the body of a female.

Internal fertilization:

Internal fertilization is a type of fertilization that takes place inside the sexual tract of the female.

Internal fertilization	External fertilization
1. Less quantity of gametes are released and only less quantity is deposited inside the female reproductive tract.	1. More quantity of gametes are released into the external environment.
2. Male gametes are discharged into the female reproductive tract.	2. Both male and female gametes are released into the environment.
3. After the fusion of gametes, the zygote develops inside the female body.	3. The zygote formed, develops outside the female body.
4. It is of three types: oviparity, viviparity, and ovoviviparity.	4. There are no other types of external fertilization.
5. There is a high rate of fertilization and the chances of survival of offspring are high.	5. The rate of fertilization is low and more number of offsprings are produced because the chances of survival are low.
6. It is commonly observed in mammals, birds, and reptiles.	6. It is commonly observed in fishes and amphibians.