Basic human biology, for all abilities, that's not offered as 'science' or leads to an exam. Most people seem to have a very sketchy idea, (or no idea at all) of how their body works and how all the body's systems are linked. Healthy living would be taught alongside that so people have the opportunity to make informed decisions about eating, drinking, exercise, safe sex, drug taking etc. For example, the (simple) structure and function of the lungs, their direct connection to the blood circulatory system that visits every cell in the body, the effects of smoking and vaping reaching every cell in the body, why smokers cough etc. Then there's the function of the gut, food groups and the connection with a healthy diet. Etc. etc....