Both the male and female gametes are formed during a process of cellular reproduction, meiosis. During meiosis, the DNA is only replicated one time. However, the cells are divided into four separate cells. This means that the new gamete cells have only half of the number of chromosomes as the other cells. So, during meiosis, DNA or chromosomes are copied, then split into two cells (with one full set of chromosomes each), then again split into two more cells, leaving only half of the pairs of chromosomes in each new cell.These new cells with only half of the chromosomes will mature into the gametes.