This edition features: new chapters on recombinant DNA technology and genetic analysis, reflecting the major role of recombinant DNA and genetic techiques in modern cell biology; a new Chapter One that defines the book's organization and philosophy and its central dogma (that to understand cells you must understand proteins, and to understand proteins you must understand genes); a new chapter devoted solely to proteins; material on cell evolution now integrated throughout, instead of confined to a late chapter; discussions of new techniques, including electrophoretic mobility shift assays, DNA footprinting, gene replacement and transgenic animals, and role of sex lethal gene in sex determination of fruitflies; expanded coverage of developmental genetics, particularly regulation of genes in developmental processes (such as the biocoid gene); and a new part-opener, chapter-opener design.