Provides a mechanism by which the chromosome number may be kept the same from one generation to another. mitosis meiosis natural selection evolution

mitosis.

During DNA replication a pair of chromosomes of from one cell genders two duplicated chromosomes (so the number of chromosomes is duplicated), then in the mitosis process the cell split into two identical cells each with half of the duplicated chromosomes, so at the end one cell with two chromosomes form two cells each with two chromosomes. So, the new generation of cells has the same number of chromosomes.