| A | B |
|---|
| pituitary | a gland at the base of the brain |
| hypothalamus | part of the brain |
| gonadotrophin releasing factor | released at the start of puberty |
| Brain | The fastest growing organ |
| Ovaries | Female sex organs |
| testes | Male sex organs |
| testosterone | the main hormone involved in male puberty |
| oestrogen | the main hormone involved in female puberty |
| growth of pubic hair | a secondary sexual characteristic common to males and females |
| growth of facial hair | a secondary sexual characteristic in males |
| growth of breast tissue | a secondary sexual characteristic in females |
| menarche | time of the first menstrual cycle |
| cancer | uncontrolled cell division |
| proto-oncogenes | can mutate into oncogenes which can cause cancer |
| tumour suppressor genes | slow down cell division |
| carcinogen | environmental factor which increases the mutation rate |
