Adolescence

Adolescence: The change from childhood to sexual maturity
Puberty occurs at different times for everything
Puberty is controlled by the sex hormones in the ovaries and testes
The changes that boys see are: Voice deepening, growth of body hair, muscle development, enlargement of genitals, beginning of semen production
The changes that girls see are: period begins, hips broaden, breasts grow, body hair grows, ova is produced
Menstruation: A monthly cycle which stops during pregnancy and the stages of it are controlled by hormones