Health and Reproduction
Reproduction basics
You must distinguish sexual from asexual reproduction. Sexual reproduction involves gametes and fertilisation, producing variation; asexual reproduction produces genetically identical offspring. Know the human reproductive organs and their functions, the menstrual cycle, and the stages of pregnancy and birth.
Health and disease
Disease may be caused by pathogens (bacteria, viruses, fungi, protozoa), by diet, or by lifestyle. Learn how pathogens spread and how the body defends itself: skin, mucus, stomach acid, white blood cells and antibodies. Vaccination gives immunity by stimulating antibody production. A common trap is assuming antibiotics kill viruses; they do not.
Health choices
Understand the effects of smoking, alcohol, poor diet and lack of exercise, and the importance of a balanced diet with the right proportions of carbohydrates, proteins, fats, vitamins, minerals, fibre and water.
Reproduction and control
Know the role of hormones in the menstrual cycle and how contraception prevents pregnancy. Questions often ask you to interpret data on disease incidence, so read graphs carefully and distinguish correlation from cause.
Worked example
A question gives a table of disease cases before and after a vaccination campaign. Calculate the percentage reduction: subtract the later figure from the earlier one, divide by the earlier figure, multiply by 100. Then interpret: a fall in cases after vaccination supports the vaccine's protective effect, though other factors may contribute.