Essentials of Biology is an introductory biology text for non-major students that combines Dr. Sylvia Mader's superb and accessible writing style with clear visuals, a comprehensive learning system, and abundant supplements. Essentials of Biology explains the principles of biology clearly and illustrates them in a captivating, easy-to-understand manner. It emphasizes the relevance of biology to students' lives within a framework of biodiversity and is organized around the major concepts of biology—cells theory, gene theory, evolution, the theory of homeostasis, and ecosystems.