Woman has nothing to do with womb: the word began as wife-person
Old English speakers used mann to mean simply a person, of either sex. A female adult was a wifmann, a wife-person, while a male one was a wer. After the Norman Conquest mann narrowed to men, wer faded out, and the two consonants in the middle of wifmann blurred into today's woman.
Over roughly a thousand years the spelling slid from wifmann to wimmann to wumman and finally woman. Its partner term for a male, waepnedmann, was built on waepn, meaning weapon and also penis. By the late 13th century man had largely pushed wer aside, and wif shrank to mean a married woman, the modern wife. The link people often assume with womb is false; womb comes from Old English wamb, belly or uterus, related to the German colloquial Wamme.
Girl has shifted too. In early English it meant a young person of either sex and only settled on female children around the start of the 16th century. In the early 1970s feminists objected to calling grown women girls, and phrases such as office girl have largely dropped out of use. Spellings like womyn and wimmin appeared in feminist writing from the same decade.
Biologically, most females carry two X chromosomes, one from each parent. Every embryo looks anatomically female until about week six or seven, when a gene on the Y chromosome called SRY turns a male's gonads into testes; female development proceeds without needing gonadal hormones. Because mitochondrial DNA passes down only through the egg, genealogists can follow maternal lines far into the past. Women typically have a lower proportion of red blood cells than men, 36 to 48 percent against 41 to 50, because they have less testosterone driving the kidney hormone erythropoietin, and their heart muscle has a finer texture and ages more slowly.
Menarche arrives on average at 12 to 13 and menopause usually between 49 and 52. Slightly fewer girls than boys are born, about 1 to 1.05, and in 2015 the world counted 1018 men for every 1000 women. Coming-of-age customs range from the Jewish bat mitzvah to the Latin American quinceanera.
Source: Woman
