
A man is an adult
male
Male (symbol: ♂) is the sex of an organism that produces the gamete (sex cell) known as sperm, which fuses with the larger female gamete, or ovum, in the process of fertilization.
A male organism cannot reproduce sexually without access to ...
human. Prior to adulthood, a male human is referred to as a
boy (a male
child
A child ( : children) is a human being between the stages of birth and puberty, or between the developmental period of infancy and puberty. The legal definition of ''child'' generally refers to a minor, otherwise known as a person younger ...
or
adolescent). Like most other male
mammal
Mammals () are a group of vertebrate animals constituting the class Mammalia (), characterized by the presence of mammary glands which in females produce milk for feeding (nursing) their young, a neocortex (a region of the brain), fur or ...
s, a man's
genome
In the fields of molecular biology and genetics, a genome is all the genetic information of an organism. It consists of nucleotide sequences of DNA (or RNA in RNA viruses). The nuclear genome includes protein-coding genes and non-coding ge ...
usually inherits an
X chromosome from the mother and a
Y chromosome from the father.
Sex differentiation
Sexual differentiation is the process of development of the sex differences between males and females from an undifferentiated zygote. Sex-determination system, Sex determination is often distinct from sex differentiation; sex determination is the ...
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
A penis (plural ''penises'' or ''penes'' () is the primary sexual organ that male animals use to inseminate females (or hermaphrodites) during copulation. Such organs occur in many animals, both vertebrat