This text gives an integrated account of the structure and function of genes in both prokaryotic and eukaryotic organisms. It begins with an introductory overview of material that the student should have encountered in previous courses. There follows a detailed examination of the role and function of DNA. The third part of the book discusses translation and has been thoroughly up-dated to reflect new knowledge. The sections on gene expression have also been modernized and updated. The book concludes with chapters examining in detail the role of genes in some of the key areas of molecular cell biology research, development and oncogenesis. This text intended for undergraduates and research students following courses in: genetics; cell biology; molecular biology; biochemistry; microbiology; virology; and preclinical medicine.