Campbell Essential Biology Plus Mastering Biology (7th Edition)

Book Preface

Biology education has been transformed in the last decade. The non-majors introductory biology course was (in most cases) originally conceived as a slightly less deep and broad version of the general biology course. But a growing recognition of the importance of this course—one that is often the most widely enrolled within the department, and one that serves as the sole source of science education for many students—has prompted a reevaluation of priorities and a reformulation of pedagogy. Many instructors have narrowed the focus of the course from a detailed compendium of facts to an exploration of broader themes within the discipline—themes such as the central role of evolution and an understanding of the process of science. For many educators, the goals have shifted from communicating a great number of bits of information toward providing a deep understanding of fewer, but broader, principles. Luckily for anyone teaching or learning biology, opportunities to marvel at the natural world and the life within it abound. Furthermore, nearly everyone realizes that the subject of biology has a significant impact on his or her own life through its connections to medicine, biotechnology, agriculture, environmental issues, forensics, and many other areas. Our primary goal in writing Campbell Essential Biology is to help teachers motivate and educate the next generation of citizens by communicating the broad themes that course through our innate curiosity about life.

Goals of the Book
Although our world is rich with “teachable moments” and learning opportunities, an explosion of knowledge threatens to bury a curious person under an avalanche of information. “So much biology, so little time” is the universal lament of biology educators. Neil Campbell conceived of Campbell Essential Biology as a tool to help teachers and students focus on the most important areas of biology. To that end, the book is organized into four core areas: cells, genes, evolution, and ecology. Dr. Campbell’s vision, which we carry on and extend in this edition, has enabled us to keep Campbell Essential Biology manageable in size and thoughtful in the development of the concepts that are most fundamental to understanding life. We’ve aligned this new edition with today’s “less is more” approach in biology education for nonscience majors—where the emphasis is on fewer topics but broader themes—while never allowing the important content to be diluted.

We formulated our approach after countless conversations with teachers and students in which we noticed some important trends in how biology is taught. In particular, many instructors identify three goals: (1) to engage students by relating biology content to their lives and the greater society;(2) to help students understand the process of science by teaching critical thinking skills that can be used in everyday life; and (3) to demonstrate how biology’s broader themes—such as evolution and the relationship of structure to function—serve to unify the entire subject. To help achieve these goals, every chapter of this book includes several important features. First, a chapter-opening essay called Biology and Society highlights a connection between the chapter’s core content and students’ lives. Second, an essay called The Process of Science (in the body of the chapter) describe how the scientific process has illuminated the topic at hand, using a classic or modern experiment as an example. Third, a chapter-closing Evolution Connection essay relates the chapter to biology’s unifying theme of evolution. Fourth, the broad themes that unify all subjects within biology are explicitly called out (in blue) multiple times within each chapter. Finally, to maintain a cohesive narrative through out each chapter, the content is tied together with a unifying chapter thread, a relevant high-interest topic that is touched on several times in the chapter and woven throughout the three feature essays. Thus, this unifying chapter thread ties together the pedagogical goals of the course, using a topic that is compelling and relevant to students.

New to This Edition

This latest edition of Campbell Essential Biology goes even further than previous editions to help students relate the material to their lives, understand the process of science, and appreciate how broad themes unify all aspects of biology. To this end, we’ve added significant new features and content to this edition:

■ A new approach to teaching the process of science. Conveying the process of science to nonscience-major undergraduate students is one of the most important goals of this course. Traditionally, we taught the scientific method as a predefined series of steps to be followed
in an exact order (observation, hypothesis, experiment, and so forth). Many instructors have shifted away from such a specific flow chart to a more nuanced approach that involves multiple pathways, frequent restarts, and other features that more accurately reflect how science is actually undertaken. Accordingly, we have revised the way that the process of science is discussed within our text, both in Chapter 1 (where the process is discussed in detail) and in The Process of Science essay in every chapter of the textbook. Rather than using specific terms in a specific order to describe the process, we now divide it into three broad interrelated areas: background, method, and results. We believe that this new approach better conveys how science actually proceeds and demystifies the topic fornon- scientists. Chapter 1 also contains important information that promotes critical thinking, such as discussion of control groups, pseudoscience, and recognizing reliable sources of information. We believe that providing students with such critical-thinking tools is one of the most important outcomes of the nonscience-major introductory course.
■ Major themes in biology incorporated throughout the book. In 2009, the American Association for the Advancement of Science published a document that served as a call to action in undergraduate biology education. The principles of this document, which is titled “Vision and Change,” are becoming widely accepted throughout the biology education community. “Vision and Change” presents five core concepts that serve as the foundation of undergraduate biology. In this edition of Campbell Essential Biology, we repeatedly and explicitly link book content to themes multiple times in each chapter, calling out such instances with boldfaced blue text. For example, in Chapter 4 (A Tour of the Cell), the interrelationships of cellular structures are used to illustrate the theme of interactions within biological systems. The plasma membrane is presented as an example of the relationship between structure and function. The cellular structures in the pathway from DNA to protein are used to illustrate the importance of information flow. The chloroplasts and mitochondria serve as an example of the transformations of energy and matter. The DNA within these structures is also used to illustrate biology’s overarching theme of evolution. Students will find three to five examples of themes called out in each chapter, which will help them see the connections between these major themes and the course content. To reinforce these connections, this edition of Campbell Essential Biology includes new end-of-chapter questions and Mastering Biology activities that promote critical thinking relating to these themes. Additionally, PowerPoint© lecture slides have been updated to incorporate chapter examples and offer guidance to faculty on how to include in these themes within classroom lectures.
■ Updated connections to students’ lives. In every edition of Campbell Essential Biology, we seek to improve and extend the ways that we connect the course content to students’ lives. Accordingly, every chapter begins with an improved feature called Why It Matters showing the relevance of the chapter content from the very start. Additionally, with every edition, we introduce some new
unifying chapter threads intended to improve student relevance. For example, this edition includes new threads that discuss evolution in a human-dominated world (Chapter 14) and the importance of biodiversity to human affairs (Chapter 20). As always, we include some updated Biology and Society chapter-opening essays (such as “A Solar Revolution” in Chapter 7), The Process of Science sections (such as a recent experiment investigating the efficacy of radiation therapy to treat prostate cancer, in Chapter 2), and Evolution Connection chapter-closing essays (such as an updated discussion of biodiversity hot spots in Chapter 20). As we always do, this edition includes many content updates that connect to students’ lives, such as information on cutting-edge cancer therapies (Chapter 8) and recent examples of DNA profiling (Chapter 12).
■ Developing data literacy through infographics. Many nonscience-major students express anxiety when faced with numerical data, yet the ability to interpret data can help with many important decisions we all face. Increasingly, the general public encounters information in the form of infographics, visual images used to represent data. Consistent with our goal of preparing students to approach important issues critically, this edition includes a series of new infographics, or Visualizing the Data figures. Examples include the elemental composition of the human body (Chapter 2), a comparison of calories burned through exercise versus calories consumed in common foods (Chapter 5), and ecological footprints (Chapter 19). In addition to the printed form, these infographics are available as an interactive feature in the eText and as assignable tutorial questions within Mastering Biology.
■ Helping students to understand key figures. For this new edition, a key figure in each chapter is supplemented by a short video explaining the concept to the student. These Figure Walkthrough videos will be embedded in the eText and will be assignable in Mastering Biology. The animations are written and narrated by authors Eric Simon and Jean Dickey, as well as teacher and contributor Rebecca Burton. Attitudes about science and scientists are often shaped by a single, required science class—this class. We hope to nurture an appreciation of nature into a genuine love of biology. In this spirit, we hope that this textbook and its supplements will encourage all readers to make biological perspectives a part of their personal worldviews. Please let us know how we are doing and how we can improve the next edition of Campbell Essential Biology

Brief Contents

1.Learning About Life 2
Unit 1 Cells 21
2 Essential Chemistry for Biology 22
3 The Molecules of Life 36
4 A Tour of the Cell 54
5 The Working Cell 74
6 Cellular Respiration: Obtaining Energy from Food 90
7 Photosynthesis: Using Light to Make Food 106
Unit 2 Genetics 119
8 Cellular Reproduction: Cells from Cells 120
9 Patterns of Inheritance 144
10 The Structure and Function of DNA 170
11 How Genes Are Controlled 196
12 DNA Technology 216
Unit 3 Evolution and Diversity 241
13 How Populations Evolve 242
14 How Biological Diversity Evolves 268
15 The Evolution of Microbial Life 292
16 The Evolution of Plants and Fungi 314
17 The Evolution of Animals 336
Unit 4 Ecology 371
18 An Introduction to Ecology and the Biosphere 372
19 Population Ecology 402
20 Communities and Ecosystems 424
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