Question

Write any four differences between external fertilization and internal fertilization.

Answer 1

External fertilization	Internal fertilization
It occurs outside the body of the female.	It occurs inside the body of the female.
A large number of gametes are released into the surrounding medium (e.g., water) where fertilization takes place.	The male gametes are deposited in the body of the female with the help of copulatory organ.
External fertilization requires the presence of water for the sperm to be able to unite with the egg.	With internal fertilization, the presence of water is not needed.
Organisms that use external fertilization to reproduce must either live in the water or return to the water for reproduction.	Animals that have internal fertilization have completely transitioned to life on land.
A Large number of eggs and sperms are needed.	The number of gametes produced is less.
Examples: Bony fish, Amphibians, most of the Algae etc.	Examples: Reptiles, Birds, Mammals, Bryophytes and Tracheophytes (Pteridophytes, Gymnosperms, Angio­sperms), etc.