What is genetic engineering? How is it carried out and what can it do? What is cancer and can genetic engineering provide a cure? Why is AIDS so difficult to cure? Which diseases are determined genetically, and how are they passed on from parents to their children? Is intelligence genetically determined? Can gene therapy cure all our genetic diseases? Can genetic engineering solve the problem of world famine? Are genetically-engineered organisms a threat to the Earth's ecology? Should people be discriminated against by insurance companies and employers because of their genes? Who should make decisions about ethical problems created by genetic engineering? These and related questions are addressed in this clear account of genetic engineering, a new technology which will soon touch all our lives. The text should be accessible to readers with no previous scientific knowledge, explaining the underlying science in simple and lucid terms, and going on to deal with controversial issues which are already confronting society. This guide is designed for everyone who wishes to understand the potential benefits and pitfalls of the new revolution and so help to ensure that its powerful techniques are harnessed wisely.