Sex determination

SEX DETERMINATION
 * For a more complete discussion, see Genetics/General overview

The nucleus contains thread like structures called chromosomes that carry instructions and help inheritance/ transfer of characters from the parents to the off springs. Similarly in fertilized egg or zygote chromosomes are containing instructions for determining the sex of the baby.

All humans have 23 pairs of chromosomes in nuclei of their cell, giving a total of 46 per cell.Two chromosomes out of these are the sex chromosome, named X and Y and the rest 44 chromosomes are known as body chromosomes. Thus human chromosomes can be divided into two types:

1)AUTOSOMES:Body chromosomes-44 in number

2)ALLOSOMES:Sex chromosomes-2 in number

The sex chromosomes in female are of the same type i.e., X and X, while in male sex chromosomes are one X and one Y. Female egg cell contains X chromosomes and sperms in male contains two kinds of chromosomes, one kind has X chromosome and the other kind has a Y chromosome.

Your sex is determined by whether the egg (containing X chromosomes) is fertilized by a sperm containing X chromosomes or by a sperm containing a Y chromosome. 1) When a sperm containing X chromosome    fertilizes the egg, the zygote would have two X chromosomes and it  develop into a female.   2) If the sperm contributes a  Y chromosome to the egg at fertilization, the zygote would have a X and Y chromosome and develop into a male.

The sex chromosomes of the father determines the sex of an unborn baby. The belief that the mother is responsible for the sex of her baby is completely wrong and to blame her for this is totally unjustified.