Changes to the Seventh Edition

The seventh edition of Biology is the result of extensive analysis of the text and evaluation of input from biology instructors who conscientiously reviewed chapters during various stages of this revision. We have utilized the constructive comments provided by these professionals in our continuing efforts to enhance the strengths of the text. Listed first are general changes that have been made to the entire text, which is then followed by specific changes for each part.

End-of-chapter Pedagogy
The end-of-chapter student review has been greatly expanded, offering students a full-page chapter review and three assessment tools: Self Test, multiple choice questions; Test Your Visual Understanding, questions based on a figure from the chapter; and Apply Your Knowledge, critical thinking questions. The assessment doesn't end there, however. These tools are carried over to the web where the student can take an interactive version of the test and receive instructional feedback.

Inquiry Questions
In this edition we have developed Inquiry Questions, which follow the legend in figures presenting graphed data. These questions require the student to think about the information contained in the graph in even greater depth, increasing their understanding of, and facility with, the material.

Answers to both end of chapter questions and Inquiry Questions are found on the Online Learning Center at www.mhhe.com/raven7.

Volumes
We recognize that instructors don't always use the entire text, so we now offer Biology in the following volumes:

Volume 1 Chapters 1–20 Chemistry, Cell and Genetics
Volume 2 Chapters 35–51 Plant Biology and Animal Biology
Volume 3 Chapters 21–34, 52–57 Evolution, Diversity and Ecology

Content Changes by Part

Part I The Origin of Living Things
Part I was revised with the intention of creating a more solid foundation of key concepts in biology, which students can then build on in later chapters. Discussions are now clearer and better supported with illustrations.

New Topics and Revised Treatments
Chapter 1 Properties of life, hierarchical organization Revised; Additional topics in evolution New
Chapter 2 The Nature of Molecules Entire chapter revised
Chapter 3 Figures on chaperons and protein denaturing New; Protein folding, lipids Revised
Chapter 4 Figures on endosymbiosis, Domains/ Kingdoms, phylogenetic tree of life New Bacteria and archaebacteria, microfossils Revised

Part II Biology of the Cell
Randall Phillis assisted in the revision of Part II by directing the authors to concepts that needed additional detail, and by providing suggestions for improving the accuracy and parsimony of the narrative. Concepts that were covered too briefly in previous editions are now supported with more extensive discussion and new illustrations.

New Topics and Revised Treatments
Chapter 6 Membrane microdomains New Osmosis; coupled transport Revised
Chapter 7 Signal amplification, expression of cellular identification Revised
Chapter 8 Redox reactions, ATP functioning Revised
Chapter 9 ATP synthetase New; Electron transport; reducing power; chemiosmosis Revised
Chapter 10 The Calvin cycle Revised
Chapter 11 Cell cycle control New; Chromosome structure Revised

Part III Genetic and Molecular Biology

With the help of Kenneth Mason, Part III was carefully updated to incorporate the most current research. Chapter 13, Patterns of Inheritance, was rewritten for better organization and clearer presentation. Two new chapters provide expanded discussion in fields where our knowledge has grown exponentially.

Chapter 17, "Genomes" integrates plant and animal genomics, functional genomics and proteomics in a chapter that is inquiry driven rather than a discussion of techniques.

Chapter 20, "Cancer Biology and Cell Technology" explores two areas where recent advances in cell and molecular biology have the potential of revolutionizing medicine. The first is cancer, where research into the molecular events leading to cancer is beginning to suggest effective therapies. The second is cell technology, including cloning, embryonic stem cells, and the exciting and controversial proposal of therapeutic cloning.

New Topics and Revised Treatments
Chapter 12 Meiotic prophase Revised
Chapter 13 Patterns of inheritance Entire chapter revised
Chapter 14 Eukaryotic DNA replication Revised
Chapter 15 Eukaryotic transcription New
Chapter 16 The tools of genetic engineering New
Chapter 18 Small RNAs, iRNA, RNA editing New Transcriptional control in prokaryotes Revised
Chapter 19 Vertebrate embryonic axis formation, evolution of homeotic genes New Cell movement; cell induction; embryonic determination; pattern formation Revised

Part IV Evolution

The Evolution section has been revised to bring more experimental data and analysis into the discussions. Because presentation of the experimental data used to derive conclusions and concepts is key to understanding how the concepts arose from the research, you will see that graphs and charts have become more plentiful in these chapters. The evolution of many groups is reassessed in light of new molecular data.

Chapter 24, "Evolution of Genomes and Developmental Mechanisms" is a new comparative genomics chapter that addresses our emerging understanding of the evolution of development, and helps to provide a conceptual framework for the diversity chapters that follow. The chapter was developed in conjunction with Chapter 17, Genomes, to first provide students with an understanding of what we can learn about genomes, and then having learned about evolution, delve into a deeper discussion of how development has evolved to yield novel phenotypes.

New Topics and Revised Treatments
Chapter 21 Measuring fitness, components of fitness, role of selection in maintaining variation New Hardy-Weinberg Revised
Chapter 22 Darwin's finches, industrial melanism New Evidence from developmental biology for evolution Revised
Chapter 23 Plant speciation by chromosomal change, the future of evolution New

Part V Diversity of Life on Earth

The fungi chapter has been moved to the phylogenetically appropriate place in the diversity section following plant diversity. Where appropriate, chapters in the diversity unit have been updated to reflect phylogenetic changes. The thoroughly revised and rewritten Chapter 25, "Systematics and the Phylogenetic Revolution" addresses the current tension between taxonomy and systematics. The chapter can be used alone, to teach the basic concepts of diversity, or can be used as a starting place for a more in-depth study of this area of biology.

New Topics and Revised Treatments
Chapter 25 Phylogenetics and classification Entire chapter revised
Chapter 26 Virus genomes New; Viral diseases and HIV Revised
Chapter 27 Term "eubacteria" replaced with "bacteria," figures of cell structure and clades New
Chapter 28 Phylogenetic approach New; Protist disease in South, Central and North America, relationships between algae and land plants Revised
Chapter 29 Fossil evidence of ancient angiosperm Archaefructacea, evolution of triploid endosperm New Monophyletic relationships between ferns and horsetails Revised
Chapter 30 Fungi Entire chapter revised
Chapter 31 Protostomes and deuterostomes New and expanded Classification Revised
Chapter 32 Protostome phylogeny, rotifers and cycliophora Revised
Chapter 33 Mollusks, annelids, arthropods, and echinoderms combined into one chapter New
Chapter 34 Characteristics and phylogeny illustration, primate evolution New

Part VI Plant Form and Function

The plant biology chapters have been revised so that the traditional discussion of evolutionary influences on plant form and function are brought into a developmental context. Evolution is still presented as the underlying explanation for the character of vascular tissues, seeds, flowers, and fruits, however the developmental processes that produce these organs are now given more emphasis. Two previously combined topics, transport and nutrition, have been split into separate chapters allowing for more in-depth discussion of both topics.

Chapter 39, "Plant Defense Responses" is a new chapter that provides a thorough discussion of secondary compounds and their roles in both plant defense and human applications. Wound responses and R gene mediated responses are explored in depth with an emphasis on signaling pathways.

New Topics and Revised Treatments
Chapter 35 Updated photographs, discussion of genetic regulation of trichomes Revised
Chapter 36 Discussion of signal transduction in germination, comparison of roles of Hox genes in plant and animal development Revised
Chapter 37 Water relations problems, mRNA transport in phloem New
Chapter 38 Newly expanded chapter on plant nutrition. Effects of global change on photosynthesis and balance of plant nutrients, phytoremediation New Nutritional symbioses Revised and expanded
Chapter 40 Signal transduction mediated by light including phot1 New Light responses Revised
Chapter 41 Plant reproduction Entire chapter revised and reorganized

Part VII Animal Form and Function

With the assistance of Randy DiDomenico, many discussions were rewritten for better organization and clarity. Previous chapters on circulation and respiration were combined into one chapter, as were chapters on body organization and locomotion.

New Topics and Revised Treatments
Chapter 42 Combined organization of the animal body and locomotion into one chapter, coordination of organ systems New
Chapter 43 Neural, hormonal and accessory organ regulation New Small intestine discussion reorganized to group all functions together Revised
Chapter 44 Maximizing rate of gas diffusion New Integration of circulation and respiration chapter Revised
Chapter 45 Graded potentials New; Membrane and action potentials, synapses and drug addiction Revised
Chapter 46 Sensory transduction Revised
Chapter 47 The Endocrine System Entire chapter revised
Chapter 48 Immunoglobulins, illustrated table New AIDS Revised
Chapter 49 Discussion of ammonia, urea and uric acid reorganized, nephron Revised
Chapter 50 Sex determination, reptiles and birds Revised Human intercourse Omitted
Chapter 51 Combined discussion of chick and mammalian extraembryonic membranes, neurulation Revised

Part VIII Ecology and Behavior

The ecology and behavior chapters were moved to follow diversity and physiology, where these chapters are more often taught. There is now an even greater emphasis on experimental data and analysis.

New Topics and Revised Treatments
Chapter 52 Animal cognition New; Integration of animal behavior and behavioral ecology chapters Revised
Chapter 53 Introduction to ecology, integration of autoecology and population ecology New Population regulation and limitation, human population growth Revised
Chapter 54 Introduction, definition of community New Parasitism, succession, disturbance Revised
Chapter 55 Geochemical cycles, energy flow, species richness Revised
Chapter 56 Differences between aquatic and terrestrial ecosystems New Integration of biosphere and future of the biosphere chapters, global climate change, El Niño Revised
Chapter 57 Chapter organization, biodiversity hotspots, amphibian extinctions, invasive species New Economic benefits of biodiversity Revised Overview of Changes to BIOLOGY, Seventh Edition
All Cell & Genetics Chapters Extensively Revised

In addition to discussing important advances, many sections have been reworked for improved clarity.

Chapter 17, "Genomes"
This new chapter describes how researchers sequence entire genomes, and how the information is being used.

Chapter 20, "Cancer Biology and Cell Technology"
This new chapter updates progress in understanding cancer, and introduces many new advances in cloning and stem cell technology.

Evolution & Diversity Sections Extensively Revised

New RNA and genomic information is leading to a reassessment of traditional evolutionary phylogenies.

Chapter 24, "Evolution of Genomes and Developmental Mechanisms"
This new chapter explores the wealth of new information on genome sequences, and introduces the new and exciting field of "evo/devo", the evolution of development.

Treatment of Plant Biology Expanded

A total of seven plant chapters provide extensive plant biology coverage with a molecular development point of view. Chapters have been organized to lead the student through the life cycle of a plant.

Chapter 39, "Plant Defense Responses"
This new chapter captures the excitement of this area of biology, which has seen rapid advances and recent breakthroughs in understanding plant defense responses.

Ecology Chapters Updated and Expanded

Up-to-date examples have been integrated into all chapters; note the use of case histories in Chapter 57.

Physiology Chapters Reworked

Discussions of processes like nervous conduction reworked for increased clarity, and related subjects like circulation and respiration treated together.

End-of-Chapter Assessment

Two pages are now devoted to student review and assessment. A full-page chapter summary is followed by multiple choice, illustration-based and application questions.

Illustrations

Many new illustrations clarify difficult concepts; others illustrate tables to aid understanding. Wherever data are presented in graphs, the figure is accompanied by an Inquiry Question to test the student's understanding.