/ 26 March 1999

Biology lesson

n Women have two X chromosomes. Each X holds about 5 000 genes. A man has one X chromosome and one Y chromosome which only holds about 30 genes.

n The male equivalent of nymphomania is satyriasis.

n The vagina has a pH of 3,8 to 4,5. That’s more acidic than black coffee (pH 5), but less than a lemon (pH 2). Semen has an alkaline balance of pH 8.

n Foreign sperm – that is, not from a regular partner – can cause a pH imbalance in the vagina.

n Women have 480 periods in a lifetime, losing 90ml of blood each cycle.