Question

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?

Answer 1

Each ovary produces a number of immature eggs, which are connected with groups of other cells known as follicles. In humans, only one egg is usually removed at a time; however, two or more may emerge during the menstrual cycle. The egg emerges from the ovary between the 14th and 16th day of the typically 28-day menstrual cycle. Identical twins are formed when a single egg is fertilized, resulting in one zygote (monozygotic) that divides into two embryos. If the twins were born fraternal, two eggs would be released. Fraternal twins (also known as "non-identical twins") are typically formed when two fertilized eggs are implanted in the uterine wall at the same time. The two eggs produce two zygotes hence these twins are also known as dizygotic or "binovular" twins.