Animals and plants manage to make copies of themselves from one generation to the next. Scientists knew that genes carried the hereditary characteristics by means of substances inside the nucleus of the cell, but how was this done? The mystery was gradually revealed from the early 1940s to the early 1960s. Genes are made up of DNA, which carries the blueprint for inheritance.

As Isaac Asimov says, “Nothing more exciting and attractive than the interplay of cell nucleus and protein, has yet been suggested to account for the continuity of life.”

In his clear style, Asimov guides the reader to an understanding of the substance DNA—“without which living organisms could not reproduce and life as we know it could not have started.”

This book has a bit more interest than the typical “How Did We Find Out” volume because of a couple of peculiarities. One, of course, is that it’s The Double Helix for children—although not nearly as charming as Watson’s book by any means. (Asimov lampooned The Double Helix in "The Holmes-Ginsbook Device,” one of his funniest stories.)

The other is that it’s a parade of Nobel laureates. In part, this is because the story of DNA doesn’t even start until the 1860’s, so an substantial chunk of the time Asimov covers in the book is one in which Nobel prizes can be handed out—something definitely not true when one is forced to start with the ancient Greeks. This tendency is exacerbated by the last chapter, which is illustrated by David Wool pretty much as a series of portraits of the various Prize-winners with a medallion every page showing the Prize itself.

And, of course, it’s a good book about DNA for a younger audience—perhaps one just younger than the audience for The Chemicals of Life and its progeny.