The male human has a sperm cell and the female has an egg cell. The cells from the male and female that combine to form a zygote are called gametes. The human sperm and egg cells each contain 23 chromosomes. . A combination of gametes forms a zygote with 46 chromosomes. The type of cell division that produces gametes with half the normal chromosome number is the meiosis. Meiosis is the type of cell division used in sexual reproduction. It will occur in the testes and ovaries.