Helping students understand why biology matters Campbell Essential Biology makes biology interesting and understandable for non-majors biology students. This best-selling textbook, known for its scientific accuracy, clear explanations, and intuitive illustrations, has been revised to further emphasize the relevance of biology to everyday life, using memorable analogies, real-world examples, conversational language, engaging new Why Biology Matters photo essays, and more. New MasteringBiology activities engage students outside of the classroom and help students develop scientific literacy skills.