The fully revised Biology: Life on Earth, Ninth Edition, has the same friendly writing style appreciated by thousands of students, but with greater emphasis on engaging, real-world applications. New to this edition are "Case Study Continued" sections, which connect a chapter's case study to relevant biological topics covered in the chapter, and "Have you ever wondered?" features that respond to commonly asked questions from students. Thoroughly revised illustrations and expanded critical thinking questions have been added to each chapter and are supplemented by the powerful new MasteringBiology program that helps students make effective use of their study time outside of the classroom.An Engaging Case Study opens each chapter and is followed with new "Case Study Continued" sections that carry the thread of the case study through the chapter, concluding with a "Case Study Revisited" section that ends the chapter by tying up the main themes of the Case Study. Major sections are introduced as questions, to encourage students to find answers within a section, while minor subheadings are presented as summary statements of important biology concepts. Boxed essays in every chapter relate chapter topics to everyday issues and events that students will likely have heard about in the news: o Health Watch essays explore topics relevant to human health. o Earth Watch essays discuss important environmental challenges and possible solutions. o Scientific Inquiry essays delve into important scientific research, giving students a better appreciation of "how we know what we know." Links to Everyday Life features do just that-link topics covered in the book to the student's life, such as by providing practical advice for avoiding E. coli food contamination (Chapter 19), as well as suggestions for actions that individuals can take to minimize impacts on the environment (Chapter 30). Critical thinking questions help students to think beyond the text. (Suggested answers and hints are provided in the Instructor Resource Guide). Figure caption questions ask the student to think critically about the topic covered in the art, and to apply what they've learned from the figure to a new situation. Answers to the figure caption questions appear at the end of the text. Consider This questions in the end-of-chapter "Case Study Revisited" section provide thought-provoking questions for the student to consider in relation to the Case Study. Applying the Concepts questions at the end of each chapter challenge the student to synthesize information beyond the chapter material, and has them apply this knowledge to new situations.