BIOLOGY: THE UNITY AND DIVERSITY OF LIFE, 15th Edition, reveals the biological world in wondrous detail. Packed with eye-catching photos and images, this best-selling text engages students with applications and activities that encourage critical thinking. Chapter-opening Core Concepts help students focus on the topics that matter most in every chapter. Each section within a chapter begins with clear Learning Objectives and section-ending Take Home Messages reinforce these key concepts. Links to Earlier Concepts help students make important connections and appreciate how living systems are interconnected and interacting.