Glencoe Biology is divided into units and chapters that are organized around Themes, Big Ideas, and Main Ideas of biology to guide you in your learning. *THEME FOCUS can be found at the start of each chapter and on the Study Guide. * Big IDEA can be found at the start of each chapter. * MAIN Idea can be found at the start of each section. *Reading Preview at the start of each section lists the Essential Questions, Review Vocabulary, and New Vocabulary. *connectED logos direct you to online resources such as Animations, Interactive Tables, The Interactive Timeline, Personal Tutors, and more. Foldables help you to organize your notes.