Question

Why do fish and frog lay more number of eggs where as cow and human beings usually give birth to only one at a time?

Answer 1

This is because in water,eggs and sperms get exposed to water very easily by wind ,flow of water etc.And also other animas in water feed on these eggs hence production large number of eggs is very necessary so that atleast some of the eggs get fertilized.Unlike hens' eggs ,frogs' eggs are held together by a jelly like substance.

Answer 2

Answer:

Fishes and frogs lay more number of eggs because:

1. they are oviparous animals.
2. fertilization occurs outside their body(external fertilization).
3. eggs are exposed to water movements,wind and rainfall.(few of them may be washed away).
4. other animals in water(predators)may feed on eggs.
5. chances for fertilization may decrease if few number of eggs are produced.
6. to ensure the process of fertilization,they may produce eggs in large number.
7. in case of cows and human beings,only one ovum is produced at a time and give birth to only one at a time.

HOPE IT HELPS :)