The goal of this text is to provide an engaging and easy to use book with an innovative and interactive media program. It achieves a unique balance in emphasizing concepts without sacrificing scientific accuracy. The new MediaTutor, found at the end of each chapter, integrates the text and media by providing a brief description of the CD or WEB activity and the time requirement for completion. In creating the book and the media package, the authors and Prentice Hall reached out to the biology community—involving educators from around the country to help address the diverse needs of today's students.