An excellent outline of the major areas of molecular biology, beginning with the makeup of a cell and smoothly surveying the Watson-Crick DNA model, more recent research on how DNA works, what happens when ""the code goes wrong,"" and significant experiences with fruit flies, bacteria, and viruses. The material becomes slightly more complex when describing the most recent research on producing chromosomes and genes in the laboratory, and -- in the final chapter on genetic engineering -- careful distinctions are not made among the possible, probable, and unlikely. The material throughout is exciting and clear but necessarily limited; unfortunately there are no suggestions for further reading to extend the interest that will no doubt be aroused.