Alvin and Virginia Silverstein. 1998. 64 pages each. There are a number of key concepts that make up the core of science, and often one concept is an important part of others. For example, photosynthesis directly affects food chains, and food chains help determine the path of evolution. Each book in this series examines a fundamental concept of science, explores its development, and shows how it relates to the whole of scientific knowledge. Each book contains numerous diagrams, a thorough glossary, and many Internet resources. Hard covers.