What should we think of genetically modified plants? What does "patenting the living" mean? Is there a risk of my child having a hereditary disease? Do eugenistic threats exist? To all these questions and many more, this book bursting with information and examples provides elements of reflection. After a reminder about basic genetics, necessary to be able to understand what is at stake, it puts into historical perspective all the knowledge we have of this discipline whose recent progress totally transforms our vision of how living organisms function.