The sperm and the ovum are called haploid (as they have only 23 chromosomes) which is half the number of chromosomes seen in all the other human body cells. What is the significance behind the maintenance of this special chromosomal number in the male and female gametes?

During the process of meiosis(The process of cell division through which the germ cells such as the reproductive cells are formed), the sex cells produced are haploids (have only 23 chromosomes). This is significant as during the process of fertilization, the nucleus of the sperm (containing 23 chromosomes) and the nucleus of an egg (containing 23 chromosomes too) fuse, hence, retaining the original number of chromosomes in the zygote formed. i.e 46 chromosomes.