A gamete is a specialized sex cell that fuses with another gamete during fertilization (conception) in organisms that reproduce sexually. Gametes are produced by germ cells.

In species which produce two morphologically distinct types of gametes, and in which each individual produces only one type, a female is any individual which produces the larger type of gamete—called an ovum (or egg)—and a male produces the smaller type—called a spermatozoon (or sperm cell).