Question

When do noticeable changes begin in human in adolescence?

Answer 1

Noticeable changes begin in humans after the age of 11 years. An individual enters in to the phase of puberty which means growth and functionality of primary sex organs (testes in males and ovaries in females). The formation of sperms and ova start and the release of sex-hormones, testosterone (in males) and oestrogen (in females) starts. These hormones make secondary sexual characters to appear and noticeable changes can be seen as development of breasts, broadening of pelvic region and menstrual cycle in females and appearance of beard, hoarse voice, musculature in males.