How many eggs are released by a human ovary in a month? How many eggs do you think would have been released if the mother gave birth to identical twins? Would your answer change if the twins born were fraternal?

Only one egg is released by human ovary, in a month.

In case of identical twins, one egg was released which after fertilisation with one sperm, makes a diploid zygote cell. This first cell splits in two and each starts to develop as a seperate individual.

Since, the origin was a single zygote, both have same genetic constitution and look the same.

In case of fraternal (non-identical) twins, two eggs were released, got fertilised by two sperms to make two zygotes that will develop independently.

They develop from two different zygotes with different genetic constitution so, they do not look identical.