posted March 13, 2007 08:32 AM         

The sex of a baby is determined by the two sex chromosomes inherited from the parents. A baby will normally inherit one sex chromosome from the mother, and one from the father. A woman has two X chromosomes, so she can give either of her X chromosomes. The father can give either his X or Y chromosome.

Since the egg already contains an X chromosome (from the mother), the gender of a baby is determined by the X or Y sex chromosome of the sperm cell from the father (thus adding one more thing to the "blame it on the husband" list of things don't go as planned ).

A girl baby will result if the final arrangement is XX, and a boy will result if it is XY. As you would expect, about half of the sperm cells contain an X chromosome, and half contain a Y chromosome. It is possible to have an abnormal number of sex chromosomes, however, this is extremely rare.

Hope u understood