At Key Stage 3 (age 11 to 13 +, Years 7 to 9) schools have to teach: that fertilisation in humans and flowering plants is the fusion of a male and a female
cell; about the physical and emotional changes that take place during adolescence; about the human
reproductive system, including the menstrual
cycle and fertilization; how the foetus develops in the uterus, including the role of the placenta.
Environmental pollutants, such as commonly used insecticides and chemicals in plastics, can impair pituitary gland function, resulting in dysfunction of testosterone - producing
cells in the testicles of men and alterations in the
reproductive cycles of women.