Facts101 is your complete guide to What Is Life? Guide to Biology and Prep-U. In this book, you will learn topics such as Cells, Energy, DNA, Gene Expression, and Biotechnology, and Chromosomes and Cell Division plus much more. With key features such as key terms, people and places, Facts101 gives you all the information you need to prepare for your next exam. Our practice tests are specific to the textbook and we have designed tools to make the most of your limited study time.