Question

Why is the sex of a baby dependent on the father?

Answer 1

The mother is homogametic, meaning all her ova (eggs) carry only the X chromosome. On the other hand, the father is heterogametic, producing two distinct types of sperms where 50% carry the X chromosome and 50% carry the Y chromosome. Therefore, the sex of the baby depends entirely on which type of sperm fertilizes the egg. If an X-sperm fuses with the egg, it forms a girl (XX), and if a Y-sperm fuses, it forms a boy (XY). Hence, the father determines the biological sex of the baby.