SEX DETERMINATION IN HUMAN BEINGS
-
Information of each body function is coded by genes which are located on chromosomes.
-
All human beings have 23 pairs of chromosomes in the nuclei of their cells. Out of these 22 pairs code for somatic body parts and one pair is known as sex chromosomes.
-
Sex chromosome in male is not a perfect pair, i.e., the two members are different from each other. It is a mismatched pair in which one is a normal-sized X while the other is a short one called Y.
-
Females have a perfect pair of sex chromosomes, both called X. So women are XX, while men are XY.
-
When gametes are produced they receive one set of chromosome. Thus female produces gametes with X chromosome while males produce sperms having either X or Y chromosome.
-
During reproduction male and female gamete fuses to produce zygote.
-
The sex of a zygote depends on the type of male gamete (sperms having X or Y chromosome) that fuses with the female gamete to produce zygote.
-
If the sperm with X chromosome fuses with the female gamete (also X) the zygote will be a female.
-
If the Y chromosome is fused with the female gamete, the zygote will be a male.
-
This type of sex determination is called XX-XY type.
-
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.
