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.Chromosomes get shuffled when eggs and sperm are made. Though most adult cells contain two sets of chromosomes, sperm and egg cells are different. These special cells have just one chromosome from each pair. Which chromosome they get from each pair is random, making each sperm or egg cell unique. There is also a bit of mixing before the chromosomes are sorted into individual sperm or egg cells. Chromosomes from each pair in a mother or father, respectively, make contact and exchange pieces of DNA, creating hybrid chromosomes.
