Question

Human beings have 46 chromosomes in the nuclei of their cells. Of these 44 are known as autosomes and the last pair is termed as the sex chromosomes. This last pair is different in males and females. In males, it is XY and in females it is XX. The egg will always have (22+ X) chromosomes while a sperm will have either (22+ X) or (22 + Y) chromosomes.

During fertilisation, if an egg fuses with a (22+ Y) sperm, the resultant zygote will develop into a male child; if an egg fuses with a (22+ X) sperm, the resultant zygote will develop into a female child.