African Civilized Life Based On Chromosomes Woman One x And Man x +y = Sex

We do know nowadays, thanks to modern science, that sexuality and the ability to procrate lie in human chromosomes; each person's cell contains twenty-three pairs--in the case of a woman a pair of x chromosomes and in the case of men one x and one Y chromosomes. However, the reproductive cells...(female egg, male sperm)  each contain only one set of chromosomes, not pairs. The pairing takes place when the egg is fertilized by the sperm; the embryo thus has the twenty-three pairsof chromosomes, but only half of them come from the mother and only half from the father. The mother,having two X chromosomes, always contributes an X.The father, having both an X and a Y, may end up contributing either one; if it is an X, the baby will be female, if a Y, it will be a male.