The total number of chromosomes present in both human male and female is 46 . Out of these, two chromosomes are the sex chromosomes. In human males, the two sex chromosomes present are X and Y, while in human female, both sex chromosomes are X. During sexual reproduction, the new individual is formed by the fusion of gametes from both the parents. These gametes are haploid in nature i.e., they contain only one set of the chromosomes. They are formed by the meiosis half. When these haploid gametes fuse during fertilization the nuclei of these two gametes fuse and the chromosome number is then restored to normal. Hence the progeny formed has the same number of chromosomes as that of the parents.