Man

A man is an adult male human. Prior to adulthood, a male human is referred to as a boy.

Like most other male mammals, a man's genome usually inherits an X chromosome from the mother and a Y chromosome from the father. Sex differentiation of the male fetus is governed by the SRY gene on the Y chromosome. During puberty, hormones which stimulate androgen production result in the development of secondary sexual characteristics, thus exhibiting greater differences between the sexes. These include greater muscle mass, the growth of facial hair and a lower body fat composition.

Male anatomy is distinguished from female anatomy by the male reproductive system, which includes the penis, testicles, sperm duct, prostate gland and the epididymis, as well as secondary sex characteristics.

The word derives from Old English mann. The Old English form primarily meant "person" or "human being" and referred to men, women, and children alike. The Old English word for "man" as distinct from "woman" or "child" was wer. Mann only came to mean "man" in Middle English, replacing wer, which survives today only in the compound "werewolf" (from Old English werwulf, literally "man-wolf").[4][5]