In males, gamete production takes place in the testes. The male gamete is called sperm. Female gametes, called ova, are produced in the ovaries.

In men, sperm cells are produced all the time. In females, a single ovum or egg cell matures about once a month.

Gametes carry half of an individual's genetic information (23 chromosomes). Gametes are created in meiosis.

In germ cell fusion or fertilization, which occurs as a result of sexual intercourse, the male and female gametes are fused together. By doing so, they form a fertilized egg cell. This new cell is diploid, which means that it has 46 chromosomes. Half of these chromosomes come from the mother, whereas the other half come from the father.

The fertilized egg cell marks the beginning of a human's individual development. A new human individual begins to develop inside the mother's womb.