CBSE Class 10 Answered

This problem is taken care of by the process of meiosis occuring during formation of gametes. Meiosis is a reduction division, wherein the number of chromosomes and thereby the DNA is reduced tro half during cell division. So the daughter cells i.e. the gametes have half the number of chromosomes than the parent cells. When two such haploid gametes combine, it results in the formation of a diploid cell (zygote). In this zygote, the number of chromosomes become equal to the somatic cells of the body. The zygote gives rise to all body cells by mitosis division, so that all body cells have the same chromosome number specific to the species.