Question

why do fish and frog lay more number of eggs whereas cow and human being used Li give but to only one at a time ​

Answer 1

Answer:

Frogs and Fish lay more no.of eggs as their eggs do not have a shell for protection. ... To protect their number in the ecosystem they lay more number of eggs at a time. Whereas as humans and cows are viviparous so only one male gamet and female gamet fuse at a time so they give birth to only one at a time.

Answer 2

Explanation:

✓In fishes and frogs, fertilization is external

✓External fertilization has lesser chances of success

✓To increase chances of fertilization fishes and frogs have to lay more no. of eggs

✓In cows and humans, fertilization is internal

✓Internal fertilization has high success rate

So, internal fertilization doesn't require that many no. of eggs

Hence, in cows and humans, only one egg is produced at a time.