How is sex determined in human beings?

(N/A) Human beings exhibit male heterogamy. In humans,males $(XY)$ produce two different types of gametes,$X$ and $Y$. The human female $(XX)$ produces only one type of gametes containing $X$ chromosomes. The sex of the baby is determined by the type of male gamete that fuses with the female gamete. If the fertilizing sperm contains $X$ chromosome,then the baby produced will be a girl and if the fertilizing sperm contains $Y$ chromosome,then the baby produced will be a boy. Hence,it is a matter of chance that determines the sex of a baby. There is an equal probability of the fertilizing sperm being an $X$ or $Y$ chromosome. Thus,it is the genetic makeup of the sperm that determines the sex of the baby.