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From the start, Biology: How Life Works was envisioned not as a reference book for all of biology, but as a resource focused on foundational concepts, terms, and experiments, all placed in a framework that motivates student interest through a coherent and authentic presentation of current science. In preparing this edition, we carefully considered the latest breakthroughs and incremental, but nevertheless significant, changes across the fields of biology. We also reached out to adopters, instructors not using our book, and primary literature to determine what concepts and details are relevant, important, and necessary additions. Our integrated approach to text, media, and assessment means that all changes are carefully reflected in each of these areas.

MAJOR CHANGES AND UPDATES

We’ve greatly expanded the coverage of ecology in the second edition of Biology: How Life Works.

A new ecology chapter, Chapter 48: Biomes and Global Ecology, takes a broad look at ecology on the largest scale. It begins with how and why climates are distributed as they are around the world and introduces Earth’s major biomes. Biomes crystallize the relationships among ecology, evolution, and physical environment—landscapes look different in different parts of the world because of the morphological and physiological adaptations that plants and animals have made to different climates. The chapter is distinguished by extensive discussion of biomes in the aquatic realm, especially in the oceans.

Chapter 47: Species Interactions, Communities, and Ecosystems includes expanded coverage of the ways species interact with one another in communities. This chapter now has more detail on facilitation, herbivory, and biodiversity.

Chapter 49: The Anthropocene: Humans as a Planetary Force includes new discussions exploring how human

activities affect ecology. The chapter now examines fracking and its effects on the carbon cycle, habitat loss and its effects on biodiversity, and the overexploitation of resources and its effects on community ecology. The chapter ends with a new section on conservation biology that explores how conservationists are working to preserve natural habitats.

A new Visual Synthesis figure on the flow of matter and energy through ecosystems illustrates, explores, and physically situates the relationships among concepts from Chapters 25, 26, 47, 48, and 49. In LaunchPad, students and instructors can interact with an accompanying dynamic, zoomable, and interactive Visual Synthesis Map based on this figure.

Our new collection of over 40 in-class activities provides tools for instructors to engage their students in active learning. In-class activities are designed to address difficult concepts, and can be used with a variety of classroom sizes and teaching styles. Each activity includes a detailed activity guide for instructors.

We’ve expanded our collection of high-quality assessment questions by adding over 1000 new questions. New questions are particularly focused on higher-order thinking, including questions based on figures or data, and questions that ask students to consider how perturbing a system would affect outcomes. As in the first edition, questions are carefully aligned with core concepts from the text. New and revised assessment questions also accompany Visual Synthesis Maps, simulations, animations, and other visual media, to more effectively probe student understanding of the media tools they’ve explored.

The second edition also includes several new question types. Sequenced questions ask students several, individually scored questions about a single scenario or system. These questions often build on one another to guide students from lower-order thinking to higher-order thinking about the same concept. Multiple true–false questions ask students several, individually scored true–false questions about a single scenario or system.

Improved functionality in LaunchPad allows instructors to search the question database and filter questions by a number of variables, including core concept, difficulty level, Bloom’s level, and class setting. Metadata tags for each question show additional information at a glance, including instructional guidance for select questions.

NEW MEDIA

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Cell Communities Visual Synthesis Map to accompany the printed Visual Synthesis figure

Virus Visual Synthesis Map to accompany the printed Visual Synthesis figure

New Visual Synthesis figure and map on the Flow of Matter and Energy in Ecosystems

Virus Video featuring author Rob Lue

Cell Membrane simulation

New Animations

Chapter 9: Basic Principles of Cell Signaling

Chapter 9: G protein-coupled Receptor Signaling

Chapter 9: Signal Amplification

Chapter 10: Dynamic Nature of Microtubules

Chapter 10: Motor Proteins

Chapter 10: Dynamic Nature of Actin Filaments

Chapter 19: Lac Operon

Chapter 20: ABC Model of Floral Development

Chapter 40: Glucose Absorption in the Small Intestine

Chapter 42: Gastrulation

NEW TOPICS AND OTHER REVISIONS

The following is a detailed list of content changes in this edition. These range from the very small (nucleotides shown at physiological pH) to quite substantial (an entire new chapter in the ecology section). Especially important changes are indicated with an asterisk ( ).

New coverage of functional groups (Chapter 2)

Nucleotides now shown at physiological pH (Chapter 3)

Amino acids now shown at physiological pH (Chapter 4)

The story of the evolution of photosynthesis now brought together in a single major section at the end of Chapter 8 (section 8.5)

Chapters 9 and 10 streamlined to better match our mission statement

A new discussion of cellular response and what determines it (Chapter 9)

New inclusion of the trombone model of DNA replication (Chapter 12)

Addition of CRISPR technology (Chapter 12)

Expanded coverage of retrotransposons and reverse transcriptase (Chapter 13)

A new How Do We Know? figure explaining Mendel’s experimental results (Chapter 16)

New coverage of the mechanism of X-inactivation (Chapter 19)

An expanded discussion of non-random mating and inbreeding depression (Chapter 21)

Addition of the effect of mass extinctions on species diversity (Chapter 23)

Updated discussion of the relationship between Neanderthals and Homo sapiens, as well as Denisovans (Chapter 24)

Significantly revised link between the carbon cycle, biodiversity, and ecology (Chapter 25)

New branching order of the eukaryote tree to reflect new research in the past three years (Chapter 27 and onward)

A new paragraph on ciliates (Chapter 27)

A new explanation of protist diversity (Chapter 27)

A new discussion of plant nutrients with a table (Chapter 29)

An enhanced discussion of seeds, including the development of the embryo and dispersal structures (Chapter 30)

Addition of apomixis (Chapter 30)

The section on the role of plant sensory systems in the timing of plant reproduction moved from Chapter 30 to Chapter 31

Completely revised explanation of the basis forangiosperm diversity (Chapter 33)

Brief descriptions of unfamiliar organisms and the major groups of organisms layered in the animal physiology chapters to make it easier to teach physiology before diversity (Chapters 35-42)

Brief review of organismal form and function in the plant and animal diversity chapters (Chapters 33 and 44), allowing these chapters to be used on their own or before the physiology chapters and giving instructors maximum flexibility

A new section on the composition of blood (Chapter 39)

New diagrams of hormone feedback loops in the menstrual cycle (Chapter 42)

A new introduction to the immune system (Chapter 43)

A new discussion of nematodes (Chapter 44)

Introduction of a newly discovered species, Dendrogramma enigmatica (Chapter 44)

A simplified population growth equation (Chapter 46)

A new discussion of facilitation (Chapter 47)

An expanded discussion of herbivory (Chapter 47)

A new example of microbial symbionts (Chapter 47)

A new discussion of biodiversity and its importance (Chapter 47)

An entirely new chapter on physical processes that underlie different biomes (Chapter 48)

A new exploration of the effect of fracking on the carbon cycle (Chapter 49)

New coverage of habitat loss and biodiversity (Chapter 49)

New coverage of overexploitation of resources and its effects on community ecology (Chapter 49)

A new Core Concept and discussion of conservation biology (Chapter 49)