1 The final form of an organism - its appearance and behaviour - is called the phenotype. It is a result of the interaction of its genotype and the environment in which it develops. Explain carefully in your words what is meant by the terms genotype and phenotype.
2 Using human examples, explain how the environment can influence specified phenotypic features.
3 Give examples of features or characteristics which are exclusively under genetic control.
4 The passage mentions Huntingdon's Chorea. Find out the symptoms of this disease and explain how it is inherited.
5 Huntingdon's Chorea is a serious condition, which eventually kills those inflicted with it. Why has it not been removed from the population by natural selection?
6 Today it is possible for couples who carry a gene for an inherited disease to be offered genetic counselling before they have children. What is meant by genetic counselling? Suggest one disease, other than those already mentioned, for which carriers may benefit from genetic counselling.
8 Do you think there are situations in which a person's genetic make-up can predispose an individual to crime or antisocial behaviour? Give reasons for your answer.
