Boy





A boy is a young male human. The term is usually used for a child or an adolescent. When a male human reaches adulthood, he is described as a man. The term "boy" can be joined with a variety of other words to form compound words.

Definition, etymology, and use
According to the Merriam-Webster Dictionary, a boy is "a male child from birth to adulthood".

The word "boy" comes from Middle English boi, boye ("boy, servant"), related to other Germanic words for boy, namely East Frisian boi ("boy, young man") and West Frisian boai ("boy"). Although the exact etymology is obscure, the English and Frisian forms probably derive from an earlier Anglo-Frisian *bō-ja ("little brother"), a diminutive of the Germanic root *bō- ("brother, male relation"), from Proto-Indo-European *bhā-, *bhāt- ("father, brother"). The root is also found in Norwegian dialectal boa ("brother"), and, through a reduplicated variant *bō-bō-, in Old Norse bófi, Dutch boef "(criminal) knave, rogue", German Bube ("knave, rogue, boy"). Furthermore, the word may be related to Bōia, an Anglo-Saxon personal name.

Race
Historically, in the United States and South Africa, "boy" was not only a "neutral" term for domestics but also a disparaging term towards men of color; the term implied a subservient status. The use of the term "boy" to describe men of color has not always been used as an insult, however; for example, Thomas Branch, an early African-American Seventh-day Adventist missionary to Nyassaland (Malawi) referred to the native students as boys:Multiple politicians – including New Jersey Governor Chris Christie and former Kentucky Congressman Geoff Davis – have been criticized publicly for referring to a black man as "boy."

During an event promoting the 2017 boxing bout between Floyd Mayweather Jr. and Conor McGregor, the latter told the former to "dance for me, boy." The remarks led several boxers – including Mayweather and Andre Ward – as well as multiple commentators to accuse McGregor of racism.

Intersex and transgender issues
Some boys defy traditional gender expectations. Gender-expansive and transgender boys can face bullying and pressure to conform to traditional expectations. Some intersex children and some transgender children who were assigned female at birth may self-identify as boys.

Sex determination
Human sex is determined at fertilization when the genetic sex of the zygote has been initialized by a sperm cell containing either an X or Y chromosome. If this sperm cell contains an X chromosome, it will coincide with the X chromosome of the ovum and a girl will develop. A sperm cell carrying a Y chromosome results in an XY combination, and a boy will develop.

Genitalia
In male embryos at six to seven weeks' gestation, "the expression of a gene on the Y chromosome induces changes that result in the development of the testes". At approximately nine weeks' gestation, the production of testosterone by a male embryo results in the development of the male reproductive system. The male reproductive system includes both external and internal organs. The external organs include the penis, the scrotum, and the testicles (or testes). The penis is a cylindrical organ filled with spongy tissue. It is the organ used by boys to expel urine. When a boy reaches puberty, the penis becomes capable of ejaculating semen and impregnating a female. The foreskin of some boys' penises is removed in a process known as circumcision. The scrotum is a loose sac of skin behind the penis which contains the testicles. Testicles are oval-shaped gonads that produce sperm. A boy generally possesses two testicles. Internal male reproductive organs include the vas deferens, the ejaculatory ducts, the urethra, the seminal vesicles, and the prostate gland.

Physical maturation
When a boy reaches puberty, testosterone directly increases the size and mass of his muscles, vocal cords, and bones, deepening his voice and changing the shape of his face and skeleton. The increased secretion of testosterone from the testes during puberty causes the male secondary sexual characteristics to be manifested. Male secondary sex characteristics include:
 * Growth of body hair, including underarm, abdominal, chest hair and pubic hair.
 * Growth of facial hair.
 * Enlargement of larynx (Adam's apple) and deepening of voice.
 * Increased stature; adult males are taller than adult females, on average.
 * Heavier skull and bone structure.
 * Increased muscle mass and strength.
 * Broadening of shoulders and chest; shoulders wider than hips.
 * Increased secretions of oil and sweat glands.