The female sex is defined as the one which produces the larger [[gamete]] (the egg) and which typically bears the offspring. In contrast, the male sex has a smaller gamete (sperm) and rarely bears offspring.
Sex can also refer to sexual intercourse, the physical act of reproduction, also known as "sexual relations" or "having sex."
In some animals, sex may be assigned to specific structures rather than the entire organism. Earthworms, for example, are normally [[hermaphrodites]].