Gr 7-9-These refreshingly readable yet thorough descriptions of important scientific developments relate procedures and principles in a clear and accurate manner. Many halftone photographs, crisp diagrams, and shaded sidebars offer supplementary information in eye-appealing forms. Clear close-ups of human cells, viruses, and bacteria make discussions of these living tissues more vivid. Both books include bracketed definitions within the texts. Nardo goes beyond the various ethical aspects of cloning to reveal some of the behind-the-scenes experiences of the scientists key to the cloning of Dolly the sheep. Plant and animal cloning and their current and potential applications are given comprehensive coverage before the author turns to implications for using the procedure to clone humans. In Vaccines, Nardo describes the uses several cultures made of the principle of inoculation centuries before Edward Jenner used cowpox against smallpox. He does not belittle Jenner's role, but clarifies his position among other pioneers and then goes on to reveal how various types of vaccines work and why they are not yet the answer to preventing all diseases. The differences among live vaccines, killed vaccines, and other complex types are delineated, and accounts of the battles against smallpox, influenza, and polio impart understanding of the devastation caused by these diseases and why conquering them has been significant in human history. The author concludes with a detailed look at where science is now in terms of developing new types of vaccines and how they may be applied to AIDS and cancer.-Ann G. Brouse, Steele Memorial Library, Elmira, NY Copyright 2002 Cahners Business Information.