Study Guide for Life on Earth Author:Teresa Audesirk, Gerald Audesirk, Bruce Byers, Sonja Stampfler, Ruthanne Thompson The Student Study Companion for this edition is more useful than ever, with 50 test questions per chapter to help students prepare for exams. New to this edition are flash cards with each chapter's key terms, as well as word roots sections that help students to make connections between a word's root and its definition.