BIOLOGY: A Global Approach, Twelfth Edition
By Neil A. Campbell, Lisa A. Urry, Michael L. Cain, Steven A. Wasserman, Peter V. Minorsky and Rebecca B. Orr
Detailed Contents:
1 Biology and Its Themes 50
CONCEPT 1.1 The study of life reveals unifying themes 51
Theme: New Properties Emerge at Successive Levels of Biological
Organization 52
Theme: Life’s Processes Involve the Expression and Transmission of
Genetic Information 54
Theme: Life Requires the Transfer and Transformation of Energy
and Matter 57
Theme: From Molecules to Ecosystems, Interactions Are Important
in Biological Systems 57
CONCEPT 1.2 The Core Theme: Evolution accounts for the
unity and diversity of life 59
Classifying the Diversity of Life 60
Charles Darwin and the Theory of Natural Selection 62
The Tree of Life 63
CONCEPT 1.3 In studying nature, scientists form and test
hypotheses 64
Exploration and Observation 65
Gathering and Analyzing Data 65
Forming and Testing Hypotheses 65
The Flexibility of the Scientific Process 66
A Case Study in Scientific Inquiry: Investigating Coat Coloration in
Mouse Populations 68
Variables and Controls in Experiments 68
Theories in Science 69
CONCEPT 1.4 Science benefits from a cooperative approach
and diverse viewpoints 70
Building on the Work of Others 70
Science, Technology, and Society 71
The Value of Diverse Viewpoints in Science 72
Unit 1 The Role of Chemistry in Biology 75
Interview: Kenneth Olden 75
2 Atoms and Molecules 76
CONCEPT 2.1 Matter consists of chemical elements in pure
form and in combinations called compounds 77
Elements and Compounds 77
The Elements of Life 77
Case Study: Evolution of Tolerance to Toxic Elements 78
CONCEPT 2.2 An element’s properties depend on the
structure of its atoms 78
Subatomic Particles 78
Atomic Number and Atomic Mass 79
Isotopes 79
The Energy Levels of Electrons 80
Electron Distribution and Chemical Properties 82
Electron Orbitals 83
CONCEPT 2.3 The formation and function of molecules
and ionic compounds depend on chemical bonding between atoms 84
Covalent Bonds 84
Ionic Bonds 85
Weak Chemical Interactions 86
Molecular Shape and Function 87
CONCEPT 2.4 Chemical reactions make and break chemical bonds 88
3 The Chemistry of Water 92
CONCEPT 3.1 Polar covalent bonds in water molecules result in hydrogen bonding 93
CONCEPT 3.2 Four emergent properties of water contribute to Earth’s suitability for life 93
Cohesion of Water Molecules 93
Moderation of Temperature by Water 94
Floating of Ice on Liquid Water 96
Water: The Solvent of Life 97
Possible Evolution of Life on Other Planets 98
CONCEPT 3.3 Acidic and basic conditions affect living
organisms 99
Acids and Bases 99
The pH Scale 99
Buffers 100
Acidification: A Threat to Our Oceans 101
4 Carbon: The Basis of Molecular Diversity 104
CONCEPT 4.1 Organic chemistry is key to the origin of life 105
CONCEPT 4.2 Carbon atoms can form diverse molecules by
bonding to four other atoms 106
The Formation of Bonds with Carbon 106
Molecular Diversity Arising from Variation in Carbon
Skeletons 108
CONCEPT 4.3 A few chemical groups are key to molecular
function 110
The Chemical Groups Most Important in the Processes of Life 110
ATP: An Important Source of Energy for Cellular Processes 112
The Chemical Elements of Life: A Review 112
5 Biological Macromolecules
and Lipids 114
CONCEPT 5.1 Macromolecules are polymers, built from
monomers 115
The Synthesis and Breakdown of Polymers 115
The Diversity of Polymers 115
CONCEPT 5.2 Carbohydrates serve as fuel and building
material 116
Sugars 116
Polysaccharides 118
CONCEPT 5.3 Lipids are a diverse group of hydrophobic
molecules 120
Fats 120
Phospholipids 122
Steroids 123
CONCEPT 5.4 Proteins include a diversity of structures,
resulting in a wide range of functions 123
Amino Acids (Monomers) 123
Polypeptides (Amino Acid Polymers) 126
Protein Structure and Function 126
CONCEPT 5.5 Nucleic acids store, transmit, and help express
hereditary information 132
The Roles of Nucleic Acids 132
The Components of Nucleic Acids 132
Nucleotide Polymers 133
The Structures of DNA and RNA Molecules 134
CONCEPT 5.6 Genomics and proteomics have transformed
biological inquiry and applications 134
DNA and Proteins as Tape Measures of Evolution 135
7 Cell Structure and Function 163
CONCEPT 7.1 Biologists use microscopes and biochemistry to
study cells 164
Microscopy 164
Cell Fractionation 166
CONCEPT 7.2 Eukaryotic cells have internal membranes that
compartmentalize their functions 167
Comparing Prokaryotic and Eukaryotic Cells 167
A Panoramic View of the Eukaryotic Cell 169
CONCEPT 7.3 The eukaryotic cell’s genetic instructions are
housed in the nucleus and carried out by the ribosomes 172
The Nucleus: Information Central 172
Ribosomes: Protein Factories 172
CONCEPT 7.4 The endomembrane system regulates protein
traffic and performs metabolic functions 174
The Endoplasmic Reticulum: Biosynthetic Factory 174
The Golgi Apparatus: Shipping and Receiving Center 175
Lysosomes: Digestive Compartments 177
Vacuoles: Diverse Maintenance Compartments 178
The Endomembrane System: A Review 178
CONCEPT 7.5 Mitochondria and chloroplasts change energy
from one form to another 179
The Evolutionary Origins of Mitochondria and Chloroplasts 179
Mitochondria: Chemical Energy Conversion 180
Chloroplasts: Capture of Light Energy 180
Peroxisomes: Oxidation 182
CONCEPT 7.6 The cytoskeleton is a network of fibers that
organizes structures and activities in the cell 182
Roles of the Cytoskeleton: Support and Motility 182
Components of the Cytoskeleton 183
CONCEPT 7.7 Extracellular components and connections
between cells help coordinate cellular activities 188
Cell Walls of Plants 188
The Extracellular Matrix (ECM) of Animal Cells 188
Cell Junctions 189
CONCEPT 7.8 A cell is greater than the sum of its parts 191
8 Cell Membranes 196
CONCEPT 8.1 Cellular membranes are fluid mosaics
of lipids and proteins 197
The Fluidity of Membranes 198
Evolution of Differences in Membrane Lipid Composition 199
6 Energy and Life 141
CONCEPT 6.1 An organism’s metabolism transforms matter
and energy 142
Metabolic Pathways 142
Forms of Energy 142
The Laws of Energy Transformation 143
CONCEPT 6.2 The free-energy change of a reaction tells us
whether or not the reaction occurs spontaneously 145
Free-Energy Change, ΔG 145
Free Energy, Stability, and Equilibrium 145
Free Energy and Metabolism 146
CONCEPT 6.3 ATP powers cellular work by coupling exergonic
reactions to endergonic reactions 148
The Structure and Hydrolysis of ATP 148
How ATP Provides Energy That Performs Work 149
The Regeneration of ATP 151
CONCEPT 6.4 Enzymes speed up metabolic reactions by
lowering energy barriers 151
The Activation Energy Barrier 151
How Enzymes Speed Up Reactions 152
Substrate Specificity of Enzymes 153
Catalysis in the Enzyme’s Active Site 154
Effects of Local Conditions on Enzyme Activity 155
The Evolution of Enzymes 157
CONCEPT 6.5 Regulation of enzyme activity helps control
metabolism 157
Allosteric Regulation of Enzymes 158
Localization of Enzymes Within the Cell 159
Membrane Proteins and Their Functions 199
The Role of Membrane Carbohydrates in Cell-Cell
Recognition 200
Synthesis and Sidedness of Membranes 201
CONCEPT 8.2 Membrane structure results in selective
permeability 201
The Permeability of the Lipid Bilayer 202
Transport Proteins 202
CONCEPT 8.3 Passive transport is diffusion of a substance
across a membrane with no energy investment 202
Effects of Osmosis on Water Balance 203
Facilitated Diffusion: Passive Transport Aided by Proteins 205
CONCEPT 8.4 Active transport uses energy to move solutes
against their gradients 206
The Need for Energy in Active Transport 206
How Ion Pumps Maintain Membrane Potential 207
Cotransport: Coupled Transport by a Membrane Protein 208
CONCEPT 8.5 Bulk transport across the plasma membrane
occurs by exocytosis and endocytosis 209
Exocytosis 209
Endocytosis 209
9 Cellular Signaling 214
CONCEPT 9.1 External signals are converted to responses
within the cell 215
Evolution of Cell Signaling 215
Local and Long-Distance Signaling 217
The Three Stages of Cell Signaling: A Preview 218
CONCEPT 9.2 Signal reception: A signaling molecule binds to
a receptor, causing it to change shape 219
Receptors in the Plasma Membrane 219
Intracellular Receptors 222
CONCEPT 9.3 Signal transduction: Cascades of molecular
interactions transmit signals from receptors to relay molecules
in the cell 223
Signal Transduction Pathways 223
Protein Phosphorylation and Dephosphorylation 224
Small Molecules and Ions as Second Messengers 225
CONCEPT 9.4 Cellular response: Cell signaling leads to
regulation of transcription or cytoplasmic activities 228
Nuclear and Cytoplasmic Responses 228
Regulation of the Response 228
CONCEPT 9.5 Apoptosis requires integration of multiple
cell-signaling pathways 231
Apoptosis in the Soil Worm Caenorhabditis elegans 232
Apoptotic Pathways and the Signals That Trigger Them 232
10 Cell Respiration 236
CONCEPT 10.1 Catabolic pathways yield energy by oxidizing
organic fuels 237
Catabolic Pathways and Production of ATP 237
Redox Reactions: Oxidation and Reduction 237
The Stages of Cellular Respiration: A Preview 240
CONCEPT 10.2 Glycolysis harvests chemical energy by
oxidizing glucose to pyruvate 242
CONCEPT 10.3 After pyruvate is oxidized, the citric acid
cycle completes the energy-yielding oxidation of organic
molecules 243
Oxidation of Pyruvate to Acetyl CoA 243
The Citric Acid Cycle 244
CONCEPT 10.4 During oxidative phosphorylation,
chemiosmosis couples electron transport to ATP synthesis 246
The Pathway of Electron Transport 246
Chemiosmosis: The Energy-Coupling Mechanism 247
An Accounting of ATP Production by Cellular Respiration 249
CONCEPT 10.5 Fermentation and anaerobic respiration
enable cells to produce ATP without the use of oxygen 251
Types of Fermentation 252
Comparing Fermentation with Anaerobic and Aerobic
Respiration 253
The Evolutionary Significance of Glycolysis 254
CONCEPT 10.6 Glycolysis and the citric acid cycle connect to
many other metabolic pathways 254
The Versatility of Catabolism 254
Biosynthesis (Anabolic Pathways) 255
Regulation of Cellular Respiration via Feedback Mechanisms 255
11 Photosynthetic Processes 259
CONCEPT 11.1 Photosynthesis feeds the biosphere 260
CONCEPT 11.2 Photosynthesis converts light energy to the
chemical energy of food 261
Chloroplasts: The Sites of Photosynthesis in Plants 261
Tracking Atoms Through Photosynthesis 261
The Two Stages of Photosynthesis: A Preview 263
CONCEPT 11.3 The light reactions convert solar energy to the
chemical energy of ATP and NADPH 264
The Nature of Sunlight 264
Photosynthetic Pigments: The Light Receptors 264
Excitation of Chlorophyll by Light 267
A Photosystem: A Reaction-Center Complex Associated with
Light-Harvesting Complexes 267
Linear Electron Flow 269
Cyclic Electron Flow 270
A Comparison of Chemiosmosis in Chloroplasts and
Mitochondria 271
CONCEPT 11.4 The Calvin cycle uses the chemical energy of
ATP and NADPH to reduce CO2 to sugar 273
CONCEPT 11.5 Alternative mechanisms of carbon fixation
have evolved in hot, arid climates 275
Photorespiration: An Evolutionary Relic? 275
C4 Plants 275
CAM Plants 277
CONCEPT 11.6 Photosynthesis is essential for life on Earth: a
review 278
12 Mitosis 284
CONCEPT 12.1 Most cell division results in genetically
identical daughter cells 285
Key Roles of Cell Division 285
Cellular Organization of the Genetic Material 285
Distribution of Chromosomes During Eukaryotic Cell Division 286
CONCEPT 12.2 The mitotic phase alternates with interphase in
the cell cycle 287
Phases of the Cell Cycle 287
The Mitotic Spindle: A Closer Look 290
Cytokinesis: A Closer Look 291
Binary Fission in Bacteria 292
The Evolution of Mitosis 293
CONCEPT 12.3 The eukaryotic cell cycle is regulated by a
molecular control system 294
The Cell Cycle Control System 294
Loss of Cell Cycle Controls in Cancer Cells 298
13 Sexual Life Cycles and Meiosis 304
CONCEPT 13.1 Offspring acquire genes from parents by
inheriting chromosomes 305
Inheritance of Genes 305
Comparison of Asexual and Sexual Reproduction 305
CONCEPT 13.2 Fertilization and meiosis alternate in sexual life
cycles 306
Sets of Chromosomes in Human Cells 306
Behavior of Chromosome Sets in the Human Life Cycle 307
The Variety of Sexual Life Cycles 308
CONCEPT 13.3 Meiosis reduces the number of chromosome
sets from diploid to haploid 309
The Stages of Meiosis 309
Crossing Over and Synapsis During Prophase I 312
A Comparison of Mitosis and Meiosis 312
CONCEPT 13.4 Genetic variation produced in sexual life cycles
contributes to evolution 315
Origins of Genetic Variation Among Offspring 315
The Evolutionary Significance of Genetic Variation Within
Populations 316
14 Mendelian Genetics 319
CONCEPT 14.1 Mendel used the scientific approach to
identify two laws of inheritance 320
Mendel’s Experimental, Quantitative Approach 320
The Law of Segregation 321
The Law of Independent
Assortment 324
CONCEPT 14.2 Probability
laws govern Mendelian
inheritance 326
The Multiplication and Addition
Rules Applied to Monohybrid
Crosses 327
Solving Complex Genetics
Problems with the Rules
of Probability 327
CONCEPT 14.3 Inheritance patterns are often more complex
than predicted by simple Mendelian genetics 328
Extending Mendelian Genetics for a Single Gene 328
Extending Mendelian Genetics for Two or More Genes 331
Nature and Nurture: The Environmental Impact on
Phenotype 332
A Mendelian View of Heredity and Variation 332
CONCEPT 14.4 Many human traits follow Mendelian
patterns of inheritance 334
Pedigree Analysis 334
Recessively Inherited Disorders 335
Dominantly Inherited Disorders 337
Multifactorial Disorders 337
Genetic Testing and Counseling 337
15 Linkage and Chromosomes 344
CONCEPT 15.1 Mendelian inheritance has its physical basis in
the behavior of chromosomes 345
Morgan’s Choice of Experimental Organism 345
Correlating Behavior of a Gene’s Alleles with Behavior of a
Chromosome Pair: Scientific Inquiry 345
CONCEPT 15.2 Sex-linked genes exhibit unique patterns of
inheritance 348
The Chromosomal Basis of Sex 348
Inheritance of X-Linked Genes 349
X Inactivation in Female Mammals 350
CONCEPT 15.3 Linked genes tend to be inherited together
because they are located near each other on the same
chromosome 351
How Linkage Affects Inheritance 351
Genetic Recombination and Linkage 352
Mapping the Distance Between Genes Using Recombination Data:
Scientific Inquiry 355
CONCEPT 15.4 Alterations of chromosome number or
structure cause some genetic disorders 356
Abnormal Chromosome Number 357
Alterations of Chromosome Structure 357
Human Conditions Due to Chromosomal Alterations 358
CONCEPT 15.5 Some inheritance patterns are exceptions to
standard Mendelian inheritance 360
Genomic Imprinting 360
Inheritance of Organelle Genes 361
16 Nucleic Acids and Inheritance 364
CONCEPT 16.1 DNA is the genetic material 365
The Search for the Genetic Material: Scientific Inquiry 365
Building a Structural Model of DNA 367
CONCEPT 16.2 Many proteins work together in DNA
replication and repair 370
The Basic Principle: Base Pairing to a Template Strand 371
DNA Replication: A Closer Look 372
Proofreading and Repairing DNA 377
Evolutionary Significance of Altered DNA Nucleotides 378
Replicating the Ends of DNA Molecules 378
CONCEPT 16.3 A chromosome consists of a DNA molecule
packed together with proteins 380
17 Expression of Genes 385
CONCEPT 17.1 Genes specify proteins via transcription and
translation 386
Evidence from Studying Metabolic Defects 386
Basic Principles of Transcription and Translation 387
The Genetic Code 390
CONCEPT 17.2 Transcription is the DNA-directed synthesis of
RNA: A Closer Look 392
Molecular Components of Transcription 392
Synthesis of an RNA Transcript 392
CONCEPT 17.3 Eukaryotic cells modify RNA after
transcription 395
Alteration of mRNA Ends 395
Split Genes and RNA Splicing 395
CONCEPT 17.4 Translation is the RNA-directed synthesis of a
polypeptide: A Closer Look 397
Molecular Components of Translation 398
Building a Polypeptide 400
Completing and Targeting the Functional Protein 402
Making Multiple Polypeptides in Bacteria and Eukaryotes 405
CONCEPT 17.5 Mutations of one or a few nucleotides can
affect protein structure and function 407
Types of Small-Scale Mutations 407
New Mutations and Mutagens 410
Using CRISPR to Edit Genes and Correct Disease-Causing
Mutations 410
What Is a Gene? Revisiting the Question 411
18 Control of Gene Expression 415
CONCEPT 18.1 Bacteria often respond to environmental
change by regulating transcription 416
Operons: The Basic Concept 416
Repressible and Inducible Operons: Two Types of Negative Gene
Regulation 418
Positive Gene Regulation 419
CONCEPT 18.2 Eukaryotic gene expression is regulated at
many stages 420
Differential Gene Expression 420
Regulation of Chromatin Structure 421
Regulation of Transcription Initiation 423
Mechanisms of Post-transcriptional Regulation 427
CONCEPT 18.3 Noncoding RNAs play multiple roles in
controlling gene expression 429
Effects on mRNAs by MicroRNAs and Small Interfering RNAs 429
Chromatin Remodeling and Effects on Transcription by
ncRNAs 430
CONCEPT 18.4 A program of differential gene expression
leads to the different cell types in a multicellular organism 431
A Genetic Program for Embryonic Development 431
Cytoplasmic Determinants and Inductive Signals 432
Sequential Regulation of Gene Expression During Cellular
Differentiation 433
Pattern Formation: Setting Up the Body Plan 434
CONCEPT 18.5 Cancer results from genetic changes that affect
cell cycle control 438
Types of Genes Associated with Cancer 438
Interference with Normal Cell-Signaling
Pathways 439
The Multistep Model of Cancer Development 441
Inherited Predisposition and Environmental Factors Contributing
to Cancer 444
The Role of Viruses in Cancer 444
19 DNA Technology 449
CONCEPT 19.1 DNA sequencing and DNA cloning are
valuable tools for genetic engineering and biological
inquiry 450
DNA Sequencing 450
Making Multiple Copies of a Gene or Other DNA
Segment 452
Using Restriction Enzymes to Make a Recombinant DNA
Plasmid 453
Amplifying DNA: The Polymerase Chain Reaction (PCR) and Its
Use in DNA Cloning 454
Expressing Cloned Eukaryotic Genes 456
CONCEPT 19.2 Biologists use DNA technology to study gene
expression and function 457
Analyzing Gene Expression 457
Determining Gene Function 460
CONCEPT 19.3 Cloned organisms and stem cells are useful for
basic research and other applications 462
Cloning Plants: Single-Cell Cultures 462
Cloning Animals: Nuclear Transplantation 462
Stem Cells of Animals 464
CONCEPT 19.4 The practical applications of DNA-based
biotechnology affect our lives in many ways 467
Medical Applications 467
Forensic Evidence and Genetic Profiles 470
Environmental Cleanup 471
Agricultural Applications 471
Safety and Ethical Questions Raised by DNA Technology 472
20 The Evolution of Genomes 476
CONCEPT 20.1 The Human Genome Project fostered
development of faster, less expensive sequencing
techniques 477
CONCEPT 20.2 Scientists use bioinformatics to analyze
genomes and their functions 478
Centralized Resources for Analyzing Genome Sequences 478
Identifying Protein-Coding Genes and Understanding Their
Functions 479
Understanding Genes and Gene Expression at the Systems Level 480
CONCEPT 20.3 Genomes vary in size, number of genes,
and gene density 482
Genome Size 482
Number of Genes 483
Gene Density and Noncoding DNA 483
CONCEPT 20.4 Multicellular eukaryotes have a lot of
noncoding DNA and many multigene families 484
Transposable Elements and Related Sequences 485
Other Repetitive DNA, Including Simple Sequence DNA 486
Genes and Multigene Families 486
CONCEPT 20.5 Duplication, rearrangement, and mutation of
DNA contribute to genome evolution 488
Duplication of Entire Chromosome Sets 488
Alterations of Chromosome
Structure 488
Duplication and Divergence of Gene-
Sized Regions of DNA 489
Rearrangements of Parts of Genes:
Exon Duplication and Exon
Shuffling 490
How Transposable Elements
Contribute to Genome
Evolution 493
CONCEPT 20.6 Comparing genome
sequences provides clues to
evolution and development 493
Comparing Genomes 493
Widespread Conservation of
Developmental Genes Among
Animals 497
Unit 4 Evolution 501
Interview: Cassandra Extavour 501
21 How Evolution Works 502
CONCEPT 21.1 The Darwinian revolution challenged
traditional views of a young Earth inhabited by unchanging
species 503
Endless Forms Most Beautiful 503
Scala Naturae and Classification of Species 504
Ideas About Change over Time 504
Lamarck’s Hypothesis of Evolution 505
CONCEPT 21.2 Descent with modification by natural selection
explains the adaptations of organisms and the unity and
diversity of life 505
Darwin’s Research 505
Ideas from The Origin of Species 507
Key Features of Natural Selection 510
CONCEPT 21.3 Evolution is supported by an overwhelming
amount of scientific evidence 510
Direct Observations of Evolutionary Change 511
Homology 513
The Fossil Record 515
Biogeography 516
What Is Theoretical About Darwin’s View of Life? 517
22 Phylogenetic Reconstruction 521
CONCEPT 22.1 Phylogenies show evolutionary
relationships 522
Binomial Nomenclature 522
Hierarchical Classification 522
Linking Classification and Phylogeny 523
What We Can and Cannot Learn from Phylogenetic Trees 523
Applying Phylogenies 525
CONCEPT 22.2 Phylogenies are inferred from morphological
and molecular data 526
Morphological and Molecular Homologies 526
Sorting Homology from Analogy 526
Evaluating Molecular Homologies 527
CONCEPT 22.3 Shared characters are used to construct
phylogenetic trees 527
Cladistics 527
Phylogenetic Trees with Proportional Branch Lengths 529
Maximum Parsimony and Maximum Likelihood 530
Phylogenetic Trees as Hypotheses 532
CONCEPT 22.4 An organism’s evolutionary history is
documented in its genome 533
Gene Duplications and Gene Families 533
Genome Evolution 534
CONCEPT 22.5 Molecular clocks help track evolutionary
time 534
Molecular Clocks 534
Applying a Molecular Clock: Dating the Origin of HIV 535
CONCEPT 22.6 Our understanding of the tree of life
continues to change based on new data 536
From Two Kingdoms to Three Domains 536
The Important Role of Horizontal Gene Transfer 536
23 Microevolution 542
CONCEPT 23.1 Genetic variation makes evolution
possible 543
Genetic Variation 543
Sources of Genetic Variation 544
CONCEPT 23.2 The Hardy-Weinberg equation can be used to
test whether a population is evolving 545
Gene Pools and Allele Frequencies 546
The Hardy-Weinberg Equation 546
CONCEPT 23.3 Natural selection, genetic drift, and gene flow
can alter allele frequencies in a population 549
Natural Selection 550
Genetic Drift 550
Gene Flow 552
CONCEPT 23.4 Natural selection is the only mechanism that
consistently causes adaptive evolution 553
Natural Selection: A Closer Look 553
The Key Role of Natural Selection in Adaptive
Evolution 554
Sexual Selection 555
Balancing Selection 556
Why Natural Selection Cannot Fashion Perfect
Organisms 557
24 Species and Speciation 562
CONCEPT 24.1 The biological species concept emphasizes
reproductive isolation 563
The Biological Species Concept 563
Other Definitions of Species 566
CONCEPT 24.2 Speciation can take place with or without
geographic separation 567
Allopatric (“Other Country”) Speciation 567
Sympatric (“Same Country”) Speciation 569
Allopatric and Sympatric Speciation: A Review 572
CONCEPT 24.3 Hybrid zones reveal factors that cause
reproductive isolation 572
Patterns Within Hybrid Zones 572
Hybrid Zones and Environmental Change 573
Hybrid Zones over Time 574
CONCEPT 24.4 Speciation can occur rapidly or slowly and can
result from changes in few or many genes 576
The Time Course of Speciation 576
Studying the Genetics of Speciation 578
From Speciation to Macroevolution 579
25 Macroevolution 581
CONCEPT 25.1 Conditions
on early Earth made the
origin of life possible 582
Synthesis of Organic
Compounds on Early
Earth 582
Abiotic Synthesis of
Macromolecules 583
Protocells 583
Self-Replicating RNA 584
CONCEPT 25.2 The fossil
record documents the
history of life 584
The Fossil Record 585
How Rocks and Fossils Are Dated 585
The Origin of New Groups of Organisms 586
CONCEPT 25.3 Key events in life’s history include the
origins of unicellular and multicellular organisms and the
colonization of land 588
The First Single-Celled Organisms 589
The Origin of Multicellularity 591
The Colonization of Land 592
CONCEPT 25.4 The rise and fall of groups of organisms reflect
differences in speciation and extinction rates 593
Plate Tectonics 594
Mass Extinctions 596
Adaptive Radiations 598
CONCEPT 25.5 Major changes in body form can result from
changes in the sequences and regulation of developmental
genes 600
Effects of Developmental Genes 600
The Evolution of Development 601
CONCEPT 25.6 Evolution is not goal oriented 603
Evolutionary Novelties 603
Evolutionary Trends 604
Unit 5 The Diversity of Life 609
Interview: Penny Chisholm 609
26 Introduction to Viruses 610
CONCEPT 26.1 A virus consists of a nucleic acid surrounded
by a protein coat 611
The Discovery of Viruses: Scientific Inquiry 611
Structure of Viruses 611
CONCEPT 26.2 Viruses replicate only in host cells 613
General Features of Viral Replicative Cycles 613
Replicative Cycles of Phages 614
Replicative Cycles of Animal Viruses 616
Evolution of Viruses 618
CONCEPT 26.3 Viruses and prions are formidable pathogens
in animals and plants 620
Viral Diseases in Animals 620
Emerging Viral Diseases 621
Viral Diseases in Plants 624
Prions: Proteins as Infectious Agents 624
27 Prokaryotes 627
CONCEPT 27.1 Structural and functional adaptations
contribute to prokaryotic success 628
Cell-Surface Structures 628
Motility 630
Internal Organization and DNA 631
Reproduction 631
CONCEPT 27.2 Rapid reproduction, mutation, and genetic
recombination promote genetic diversity in prokaryotes 632
Rapid Reproduction and Mutation 632
Genetic Recombination 633
CONCEPT 27.3 Diverse nutritional and metabolic adaptations
have evolved in prokaryotes 635
The Role of Oxygen in Metabolism 636
Nitrogen Metabolism 636
Metabolic Cooperation 636
CONCEPT 27.4 Prokaryotes have radiated into a diverse set
of lineages 637
An Overview of Prokaryotic Diversity 637
Bacteria 637
Archaea 639
CONCEPT 27.5 Prokaryotes play crucial roles in the
biosphere 640
Chemical Recycling 640
Ecological Interactions 641
CONCEPT 27.6 Prokaryotes have both beneficial and harmful
impacts on humans 641
Mutualistic Bacteria 641
Pathogenic Bacteria 642
Antibiotic Resistance 642
Prokaryotes in Research and Technology 643
28 The Origin and Evolution
of Eukaryotes 647
CONCEPT 28.1 Most eukaryotes are single-celled
organisms 648
Structural and Functional Diversity in Protists 648
Endosymbiosis in Eukaryotic Evolution 648
Four Supergroups of Eukaryotes 651
CONCEPT 28.2 Excavates include protists with modified
mitochondria and protists with unique flagella 651
Diplomonads and Parabasalids 654
Euglenozoans 654
CONCEPT 28.3 SAR is a highly diverse group of protists
defined by DNA similarities 655
Stramenopiles 656
Alveolates 658
Rhizarians 660
CONCEPT 28.4 Red algae and green algae are the closest
relatives of plants 663
Red Algae 663
Green Algae 664
CONCEPT 28.5 Unikonts include protists that are closely
related to fungi and animals 665
Amoebozoans 666
Opisthokonts 667
CONCEPT 28.6 Protists play key roles in ecological
communities 668
Symbiotic Protists 668
Photosynthetic Protists 668
29 Nonvascular and Seedless
Vascular Plants 672
CONCEPT 29.1 Plants evolved from green algae 673
Evidence of Algal Ancestry 673
Adaptations Enabling the Move to Land 673
Derived Traits of Plants 675
The Origin and Diversification of Plants 675
CONCEPT 29.2 Mosses and other nonvascular plants have life
cycles dominated by gametophytes 677
Bryophyte Gametophytes 678
Bryophyte Sporophytes 679
The Ecological and Economic Importance of Mosses 681
CONCEPT 29.3 Ferns and other seedless vascular plants were
the first plants to grow tall 683
Origins and Traits of Vascular Plants 683
Classification of Seedless Vascular Plants 685
The Significance of Seedless Vascular Plants 687
30 Seed Plants 690
CONCEPT 30.1 Seeds and pollen grains are key adaptations
for life on land 691
Advantages of Reduced Gametophytes 691
Heterospory: The Rule Among Seed Plants 692
Ovules and Production of
Eggs 692
Pollen and Production of
Sperm 692
The Evolutionary Advantage of
Seeds 693
CONCEPT 30.2 Gymnosperms
bear “naked” seeds, typically on
cones 694
The Life Cycle of a Pine 694
Early Seed Plants and the Rise of
Gymnosperms 695
Gymnosperm Diversity 695
CONCEPT 30.3 The reproductive adaptations of angiosperms
include flowers and fruits 698
Characteristics of Angiosperms 698
Angiosperm Evolution 701
Angiosperm Diversity 703
CONCEPT 30.4 Human welfare depends on seed plants 705
Products from Seed Plants 705
Threats to Plant Diversity 705
31 Introduction to Fungi 708
CONCEPT 31.1 Fungi are heterotrophs that feed by
absorption 709
Nutrition and Ecology 709
Body Structure 709
Specialized Hyphae in Mycorrhizal Fungi 710
CONCEPT 31.2 Fungi produce spores through sexual or
asexual life cycles 711
Sexual Reproduction 712
Asexual Reproduction 712
CONCEPT 31.3 The ancestor of fungi was an aquatic, singlecelled,
flagellated protist 713
The Origin of Fungi 713
The Move to Land 714
CONCEPT 31.4 Fungi have radiated into a diverse set of
lineages 714
Cryptomycetes and Microsporidians 715
Zoopagomycetes 716
Mucoromycetes 717
Ascomycetes 717
Basidiomycetes 719
CONCEPT 31.5 Fungi play key roles in nutrient cycling,
ecological interactions, and human welfare 721
Fungi as Decomposers 721
Fungi as Mutualists 721
Practical Uses of Fungi 724
32 An Introduction to Animal
Diversity 727
CONCEPT 32.1 Animals are multicellular, heterotrophic
eukaryotes with tissues that develop from embryonic
layers 728
Nutritional Mode 728
Cell Structure and Specialization 728
Reproduction and Development 728
CONCEPT 32.2 The history of animals spans more than half a
billion years 729
Steps in the Origin of Multicellular Animals 729
Neoproterozoic Era (1 Billion–541 Million Years Ago) 730
Paleozoic Era (541–252 Million Years Ago) 731
Mesozoic Era (252–66 Million Years Ago) 733
Cenozoic Era (66 Million Years Ago to the Present) 733
CONCEPT 32.3 Animals can be characterized by body
plans 733
Symmetry 733
Tissues 733
Body Cavities 734
Protostome and Deuterostome Development 735
CONCEPT 32.4 Views of animal phylogeny continue to be
shaped by new molecular and morphological data 736
The Diversification of Animals 736
Future Directions in Animal Systematics 738
33 Invertebrates 740
CONCEPT 33.1 Sponges are basal animals that lack
tissues 744
CONCEPT 33.2 Cnidarians are an ancient phylum of
eumetazoans 745
Medusozoans 746
Anthozoans 747
CONCEPT 33.3 Lophotrochozoans, a clade identified by
molecular data, have the widest range of animal body
forms 748
Flatworms 748
Rotifers and Acanthocephalans 751
Ectoprocts and Brachiopods 752
Molluscs 753
Annelids 757
CONCEPT 33.4 Ecdysozoans
are the most species-rich
animal group 759
Nematodes 759
Arthropods 760
CONCEPT 33.5 Echinoderms
and chordates are
deuterostomes 767
Echinoderms 767
Chordates 769
34 Vertebrates 772
CONCEPT 34.1 Chordates have a notochord and a dorsal,
hollow nerve cord 773
Derived Characters of Chordates 773
Lancelets 774
Tunicates 775
Early Chordate Evolution 776
CONCEPT 34.2 Vertebrates are chordates that have a
backbone 776
Derived Characters of Vertebrates 776
Hagfishes and Lampreys 777
Early Vertebrate Evolution 778
CONCEPT 34.3 Gnathostomes are vertebrates that have
jaws 779
Derived Characters of Gnathostomes 779
Fossil Gnathostomes 780
Chondrichthyans (Sharks, Rays, and Their
Relatives) 780
Ray-Finned Fishes and Lobe-Fins 782
CONCEPT 34.4 Tetrapods are gnathostomes that have
limbs 784
Derived Characters of Tetrapods 784
The Origin of Tetrapods 785
Amphibians 785
CONCEPT 34.5 Amniotes are tetrapods that have a terrestrially
adapted egg 788
Derived Characters of Amniotes 788
Early Amniotes 789
Reptiles 789
CONCEPT 34.6 Mammals are amniotes that have hair and
produce milk 795
Derived Characters of Mammals 795
Early Evolution of Mammals 795
Monotremes 796
Marsupials 797
Eutherians (Placental Mammals) 798
CONCEPT 34.7 Humans are mammals that have a large brain
and bipedal locomotion 802
Derived Characters of Humans 802
The Earliest Hominins 802
Australopiths 803
Bipedalism 804
Tool Use 804
Early Homo 804
Neanderthals 806
Homo sapiens 807
Unit 6 Plants: Structure and Function 811
Interview: Dennis Gonsalves 811
35 Plant Structure and Growth 812
CONCEPT 35.1 Plants have a hierarchical organization
consisting of organs, tissues, and cells 813
Vascular Plant Organs: Roots, Stems, and Leaves 813
Dermal, Vascular, and Ground Tissues 816
Common Types of Plant Cells 817
CONCEPT 35.2 Different meristems
generate new cells for primary and
secondary growth 820
CONCEPT 35.3 Primary growth
lengthens roots and shoots 822
Primary Growth of Roots 822
Primary Growth of Shoots 823
CONCEPT 35.4 Secondary growth
increases the diameter of stems and
roots in woody plants 826
The Vascular Cambium and Secondary Vascular Tissue 827
The Cork Cambium and the Production of Periderm 828
Evolution of Secondary Growth 828
CONCEPT 35.5 Growth, morphogenesis, and cell
differentiation produce the plant body 829
Model Organisms: Revolutionizing the Study of Plants 830
Growth: Cell Division and Cell Expansion 830
Morphogenesis and Pattern Formation 831
Gene Expression and the Control of Cell Differentiation 832
Shifts in Development: Phase Changes 832
Genetic Control of Flowering 833
36 Transport in Vascular Plants 838
CONCEPT 36.1 Adaptations for acquiring resources were key
steps in the evolution of vascular plants 839
Shoot Architecture and Light Capture 839
Root Architecture and Acquisition of Water and Minerals 841
CONCEPT 36.2 Different mechanisms transport substances
over short or long distances 841
The Apoplast and Symplast: Transport Continuums 841
Short-Distance Transport of Solutes Across Plasma
Membranes 842
Short-Distance Transport of Water Across Plasma Membranes 842
Long-Distance Transport: The Role of Bulk Flow 845
CONCEPT 36.3 Transpiration drives the transport of water and
minerals from roots to shoots via the xylem 846
Absorption of Water and Minerals by Root Cells 846
Transport of Water and Minerals into the Xylem 846
Bulk Flow Transport via the Xylem 846
Xylem Sap Ascent by Bulk Flow: A Review 850
CONCEPT 36.4 The rate of transpiration is regulated by
stomata 850
Stomata: Major Pathways for Water Loss 850
Mechanisms of Stomatal Opening and Closing 851
Stimuli for Stomatal Opening and Closing 852
Effects of Transpiration on Wilting and Leaf Temperature 852
Adaptations That Reduce Evaporative Water Loss 852
CONCEPT 36.5 Sugars are transported from sources to sinks
via the phloem 853
Movement from Sugar Sources to Sugar Sinks 853
Bulk Flow by Positive Pressure: The Mechanism of Translocation in
Angiosperms 854
CONCEPT 36.6 The symplast is highly dynamic 855
Changes in Plasmodesmatal Number and Pore Size 856
Phloem: An Information Superhighway 856
Electrical Signaling in the Phloem 856
37 Plant Nutrition 859
CONCEPT 37.1 Soil contains a living, complex ecosystem 860
Soil Texture 860
Topsoil Composition 860
Soil Conservation and Sustainable Agriculture 861
CONCEPT 37.2 Plant roots absorb many types of essential
elements from the soil 863
Essential Elements 864
Symptoms of Mineral Deficiency 864
Global Climate Change and Food Quality 866
CONCEPT 37.3 Plant nutrition often involves relationships
with other organisms 866
Bacteria and Plant Nutrition 868
Fungi and Plant Nutrition 871
Epiphytes, Parasitic Plants, and Carnivorous Plants 872
38 Reproduction of Flowering
Plants 876
CONCEPT 38.1 Flowers, double
fertilization, and fruits are key features
of the angiosperm life cycle 877
Flower Structure and Function 877
Methods of Pollination 879
The Angiosperm Life Cycle: An
Overview 880
Development of Female Gametophytes
(Embryo Sacs) 880
Development of Male Gametophytes in
Pollen Grains 880
Seed Development and Structure 882
Sporophyte Development from Seed to Mature Plant 883
Fruit Structure and Function 884
CONCEPT 38.2 Flowering plants reproduce sexually, asexually,
or both 887
Mechanisms of Asexual Reproduction 887
Advantages and Disadvantages of Asexual and Sexual
Reproduction 887
Mechanisms That Prevent Self-Fertilization 888
Totipotency, Vegetative Reproduction, and Tissue Culture 889
CONCEPT 38.3 People modify crops by breeding and genetic
engineering 890
Plant Breeding 891
Plant Biotechnology and Genetic Engineering 891
The Debate over Plant Biotechnology 893
39 Plant Signals and Behavior 896
CONCEPT 39.1 Signal transduction pathways link signal
reception to response 897
Reception 898
Transduction 898
Response 899
CONCEPT 39.2 Plants use chemicals to communicate 899
General Characteristics of Plant Hormones 900
A Survey of Plant Hormones 901
CONCEPT 39.3 Responses to light are critical for plant
success 909
Blue-Light Photoreceptors 909
Phytochrome Photoreceptors 910
Biological Clocks and Circadian Rhythms 911
The Effect of Light on the Biological Clock 912
Photoperiodism and Responses to Seasons 913
CONCEPT 39.4 Plants respond to a wide variety of stimuli
other than light 915
Gravity 915
Mechanical Stimuli 915
Environmental Stresses 916
CONCEPT 39.5 Plants respond to attacks by pathogens and
herbivores 920
Defenses Against Pathogens 920
Defenses Against Herbivores 921
Unit 7 Animals: Structure and Function 926
Interview: Steffanie Strathdee 926
40 The Animal Body 927
CONCEPT 40.1 Animal form and function are correlated at all
levels of organization 928
Evolution of Animal Size and Shape 928
Exchange with the Environment 928
Hierarchical Organization of Body Plans 930
Coordination and Control 934
CONCEPT 40.2 Feedback control maintains the internal
environment in many animals 935
Regulating and Conforming 935
Homeostasis 935
CONCEPT 40.3 Homeostatic processes for thermoregulation
involve form, function, and behavior 938
Endothermy and Ectothermy 938
Variation in Body Temperature 938
Balancing Heat Loss and Gain 939
Acclimatization in Thermoregulation 942
Physiological Thermostats and Fever 942
CONCEPT 40.4 Energy requirements are related to animal
size, activity, and environment 943
Energy Allocation and Use 943
Quantifying Energy Use 944
Minimum Metabolic Rate and Thermoregulation 944
Influences on Metabolic Rate 945
Torpor and Energy Conservation 946
41 Chemical Signals in Animals 953
CONCEPT 41.1 Hormones and other signaling molecules bind
to target receptors, triggering specific response
pathways 954
Intercellular Information Flow 954
Chemical Classes of Hormones 955
Cellular Hormone Response Pathways 956
Endocrine Tissues and Organs 957
CONCEPT 41.2 Feedback regulation and coordination with the
nervous system are common in hormone
pathways 958
Simple Endocrine Pathways 958
Simple Neuroendocrine Pathways 959
Feedback Regulation 959
Coordination of the Endocrine and Nervous Systems 960
Thyroid Regulation: A Hormone Cascade Pathway 962
Hormonal Regulation of Growth 963
CONCEPT 41.3 Endocrine glands respond to diverse stimuli
in regulating homeostasis, development, and
behavior 965
Parathyroid Hormone and Vitamin D: Control of Blood
Calcium 965
Adrenal Hormones: Response to Stress 966
Sex Hormones 968
Hormones and Biological Rhythms 969
Evolution of Hormone Function 969
42 Animal Digestive Systems 974
CONCEPT 42.1 An animal’s diet must supply chemical energy,
organic building blocks, and essential nutrients 975
Essential Nutrients 975
Variation in Diet 977
Dietary Deficiencies 977
Assessing Nutritional Needs 978
CONCEPT 42.2 Food processing involves ingestion, digestion,
absorption, and elimination 978
Digestive Compartments 980
CONCEPT 42.3 Organs specialized for sequential stages of
food processing form the mammalian digestive system 981
The Oral Cavity, Pharynx, and Esophagus 981
Digestion in the Stomach 983
Digestion in the Small Intestine 984
Absorption in the Small Intestine 985
Processing in the Large Intestine 986
CONCEPT 42.4 Evolutionary adaptations of vertebrate
digestive systems correlate with diet 987
Dental Adaptations 987
Stomach and Intestinal Adaptations 988
Mutualistic Adaptations 988
CONCEPT 42.5 Feedback circuits regulate digestion,
energy storage, and appetite 991
Regulation of Digestion 991
Regulation of Energy Storage 991
Regulation of Appetite and Consumption 993
43 Animal Transport Systems 997
CONCEPT 43.1 Circulatory systems link exchange surfaces
with cells throughout the body 998
Gastrovascular Cavities 998
Open and Closed Circulatory Systems 999
Organization of Vertebrate Circulatory
Systems 1000
CONCEPT 43.2 Coordinated cycles of heart contraction drive
double circulation in mammals 1002
Mammalian Circulation 1002
The Mammalian Heart: A Closer Look 1002
Maintaining the Heart’s Rhythmic Beat 1004
CONCEPT 43.3 Patterns of blood pressure and flow reflect the
structure and arrangement of blood vessels 1005
Blood Vessel Structure and Function 1005
Blood Flow Velocity 1006
Blood Pressure 1006
Capillary Function 1008
Fluid Return by the Lymphatic System 1009
CONCEPT 43.4 Blood components function in exchange,
transport, and defense 1010
Blood Composition and Function 1010
Cardiovascular Disease 1013
CONCEPT 43.5 Gas exchange occurs across specialized
respiratory surfaces 1015
Partial Pressure Gradients in Gas Exchange 1015
Respiratory Media 1015
Respiratory Surfaces 1016
Gills in Aquatic Animals 1016
Tracheal Systems in Insects 1017
Lungs 1018
CONCEPT 43.6 Breathing ventilates the lungs 1020
How an Amphibian Breathes 1020
How a Bird Breathes 1020
How a Mammal Breathes 1021
Control of Breathing in Humans 1022
CONCEPT 43.7 Adaptations for gas exchange include
pigments that bind and transport gases 1023
Coordination of Circulation and Gas Exchange 1023
Respiratory Pigments 1023
Respiratory Adaptations of Diving Mammals 1025
44 Animal Excretory Systems 1029
CONCEPT 44.1 Osmoregulation balances the uptake and loss
of water and solutes 1030
Osmosis and Osmolarity 1030
Osmoregulatory Challenges and Mechanisms 1030
Energetics of Osmoregulation 1032
Transport Epithelia in Osmoregulation 1033
CONCEPT 44.2 An animal’s nitrogenous wastes reflect its
phylogeny and habitat 1034
Forms of Nitrogenous Waste 1034
The Influence of Evolution and Environment on Nitrogenous
Wastes 1035
CONCEPT 44.3 Diverse excretory systems are variations on a
tubular theme 1035
Survey of Excretory Systems 1036
CONCEPT 44.4 The nephron is organized for stepwise
processing of blood filtrate 1039
From Blood Filtrate to Urine: A Closer Look 1039
Solute Gradients and Water Conservation 1041
Adaptations of the Vertebrate Kidney to Diverse Environments 1043
CONCEPT 44.5 Hormonal circuits link kidney function, water
balance, and blood pressure 1046
Homeostatic Regulation of the Kidney 1046
45 Animal Reproductive Systems 1051
CONCEPT 45.1 Both asexual and sexual reproduction occur in
the animal kingdom 1052
Mechanisms of Asexual Reproduction 1052
Variation in Patterns of Sexual Reproduction 1052
Reproductive Cycles 1053
Sexual Reproduction: An Evolutionary Enigma 1053
CONCEPT 45.2 Fertilization depends on mechanisms that
bring together sperm and eggs of the same species 1054
Ensuring the Survival of Offspring 1055
Gamete Production and Delivery 1055
CONCEPT 45.3 Reproductive organs produce and transport
gametes 1057
Human Male Reproductive Anatomy 1057
Human Female Reproductive Anatomy 1058
Gametogenesis 1059
CONCEPT 45.4 The interplay of tropic and sex hormones
regulates reproduction in mammals 1062
Biological Sex, Gender Identity, and Sexual Orientation in Human
Sexuality 1063
Hormonal Control of the Male Reproductive System 1063
Hormonal Control of Female Reproductive Cycles 1064
Human Sexual Response 1066
CONCEPT 45.5 In placental mammals, an embryo develops
fully within the mother’s uterus 1066
Conception, Embryonic Development, and Birth 1066
Maternal Immune Tolerance of the Embryo and Fetus 1069
Contraception and Abortion 1069
Modern Reproductive Technologies 1071
46 Development in Animals 1075
CONCEPT 46.1 Fertilization and cleavage initiate embryonic
development 1076
Fertilization 1076
Cleavage 1078
CONCEPT 46.2 Morphogenesis in animals involves specific
changes in cell shape, position, and survival 1081
Gastrulation 1081
Developmental Adaptations of Amniotes 1085
Organogenesis 1086
The Cytoskeleton in Morphogenesis 1088
CONCEPT 46.3 Cytoplasmic determinants and inductive
signals regulate cell fate 1089
Fate Mapping 1090
Axis Formation 1091
Restricting Developmental Potential 1092
Cell Fate Determination and Pattern Formation by
Inductive Signals 1093
Cilia and Cell Fate 1096
47 Animal Defenses Against
Infection 1100
CONCEPT 47.1 In innate immunity, recognition and response
rely on traits common to groups of pathogens 1101
Innate Immunity of Invertebrates 1101
Innate Immunity of Vertebrates 1102
Evasion of Innate Immunity by Pathogens 1105
CONCEPT 47.2 In adaptive immunity, receptors provide
pathogen-specific recognition 1105
Antigens as the Trigger for Adaptive Immunity 1106
Antigen Recognition by B Cells and Antibodies 1106
Antigen Recognition by T Cells 1107
B Cell and T Cell Development 1108
CONCEPT 47.3 Adaptive immunity defends against infection
of body fluids and body cells 1111
Helper T Cells: Activating Adaptive Immunity 1111
B Cells and Antibodies: A Response to Extracellular
Pathogens 1112
Cytotoxic T Cells: A Response to Infected Host Cells 1114
Summary of the Humoral and Cell-Mediated Immune
Responses 1115
Immunization 1116
Active and Passive Immunity 1116
Antibodies as Tools 1117
Immune Rejection 1117
CONCEPT 47.4 Disruptions in immune system function can
elicit or exacerbate disease 1118
Exaggerated, Self-Directed, and Diminished Immune
Responses 1118
Evolutionary Adaptations of Pathogens That Underlie Immune
System Avoidance 1119
Cancer and Immunity 1122
48 Electrical Signals
in Animals 1125
CONCEPT 48.1 Neuron structure and organization reflect
function in information transfer 1126
Neuron Structure and Function 1126
Introduction to Information Processing 1126
CONCEPT 48.2 Ion pumps and ion channels establish the
resting potential of a neuron 1127
Formation of the Resting Potential 1128
Modeling the Resting Potential 1129
CONCEPT 48.3 Action potentials are the signals conducted by
axons 1130
Hyperpolarization and Depolarization 1130
Graded Potentials and Action Potentials 1131
Generation of Action Potentials: A Closer Look 1131
Conduction of Action Potentials 1133
CONCEPT 48.4 Neurons communicate with other cells at
synapses 1135
Generation of Postsynaptic Potentials 1136
Summation of Postsynaptic Potentials 1137
Termination of Neurotransmitter Signaling 1137
Modulated Signaling at Synapses 1138
Neurotransmitters 1138
49 Neural Regulation
in Animals 1143
CONCEPT 49.1 Nervous systems consist of circuits of neurons
and supporting cells 1144
Organization of the Vertebrate Nervous System 1145
The Peripheral Nervous System 1146
Glia 1148
CONCEPT 49.2 The vertebrate brain is regionally
specialized 1149
Arousal and Sleep 1152
Biological Clock Regulation 1152
Emotions 1153
Functional Imaging of the Brain 1154
CONCEPT 49.3 The cerebral cortex controls voluntary
movement and cognitive functions 1154
Information Processing 1155
Language and Speech 1156
Lateralization of Cortical Function 1156
Frontal Lobe Function 1156
Evolution of Cognition in Vertebrates 1156
CONCEPT 49.4 Changes in synaptic connections underlie
memory and learning 1157
Neuronal Plasticity 1158
Memory and Learning 1158
Long-Term Potentiation 1159
CONCEPT 49.5 Many nervous system disorders can now be
explained in molecular terms 1160
Schizophrenia 1160
Depression 1160
The Brain’s Reward System and Drug Addiction 1161
Alzheimer’s Disease 1161
Parkinson’s Disease 1162
Future Directions in Brain Research 1162
50 Sensation and Movement
in Animals 1165
CONCEPT 50.1 Sensory receptors transduce stimulus
energy and transmit signals to the central nervous
system 1166
Sensory Reception and Transduction 1166
Transmission 1167
Perception 1167
Amplification and Adaptation 1167
Types of Sensory Receptors 1168
CONCEPT 50.2 In hearing and equilibrium, mechanoreceptors
detect moving fluid or settling particles 1170
Sensing of Gravity and Sound in Invertebrates 1170
Hearing and Equilibrium in Mammals 1170
Hearing and Equilibrium in Other Vertebrates 1174
CONCEPT 50.3 The diverse visual receptors of animals depend
on light-absorbing pigments 1175
Evolution of Visual Perception 1175
The Vertebrate Visual System 1177
CONCEPT 50.4 The senses of taste and smell rely on similar
sets of sensory receptors 1181
Taste in Mammals 1181
Smell in Humans 1182
CONCEPT 50.5 The physical interaction of protein filaments is
required for muscle function 1183
Vertebrate Skeletal Muscle 1184
Other Types of Muscle 1189
CONCEPT 50.6 Skeletal systems transform muscle contraction
into locomotion 1190
Types of Skeletal Systems 1190
Types of Locomotion 1193
Unit 8 The Ecology of Life 1197
Interview: Chelsea Rochman 1197
51 An Overview of Ecology 1198
CONCEPT 51.1 Earth’s climate varies by latitude and season
and is changing rapidly 1201
Global Climate Patterns 1201
Regional and Local Effects on Climate 1201
Effects of Vegetation on Climate 1203
Microclimate 1203
Global Climate Change 1204
CONCEPT 51.2 The distribution of terrestrial biomes is
controlled by climate and disturbance 1205
Climate and Terrestrial Biomes 1205
General Features of Terrestrial Biomes 1206
Disturbance and Terrestrial Biomes 1206
CONCEPT 51.3 Aquatic biomes are diverse and dynamic
systems that cover most of Earth 1211
Zonation in Aquatic Biomes 1211
CONCEPT 51.4 Interactions between organisms
and the environment limit the distribution of
species 1212
Dispersal and Distribution 1217
Biotic Factors 1218
Abiotic Factors 1218
CONCEPT 51.5 Ecological change and evolution
affect one another over long and short periods of
time 1221
52 Behavioral Ecology 1225
CONCEPT 52.1 Discrete sensory inputs can stimulate both
simple and complex behaviors 1226
Fixed Action Patterns 1226
Migration 1226
Behavioral Rhythms 1227
Animal Signals and Communication 1227
CONCEPT 52.2 Learning establishes specific links between
experience and behavior 1229
Experience and Behavior 1229
Learning 1230
CONCEPT 52.3 Selection for individual survival
and reproductive success can explain diverse
behaviors 1234
Evolution of Foraging Behavior 1234
Mating Behavior and Mate Choice 1235
CONCEPT 52.4 Genetic analyses and the concept of inclusive
fitness provide a basis for studying the evolution
of behavior 1240
Genetic Basis of Behavior 1241
Genetic Variation and the Evolution of
Behavior 1241
Altruism 1242
Inclusive Fitness 1243
Evolution and Human Culture 1245
53 Populations and Life History
Traits 1248
CONCEPT 53.1 Biotic and abiotic factors affect population
density, dispersion, and demographics 1249
Density and Dispersion 1249
Demographics 1251
CONCEPT 53.2 The exponential model describes
population growth in an idealized, unlimited
environment 1254
Changes in Population Size 1254
Exponential Growth 1254
CONCEPT 53.3 The logistic model describes how a
population grows more slowly as it nears its carrying
capacity 1255
The Logistic Growth Model 1256
The Logistic Model and Real Populations 1257
CONCEPT 53.4 Life history traits are products of natural
selection 1258
Diversity of Life Histories 1258
“Trade-offs” and Life Histories 1259
CONCEPT 53.5 Density-dependent factors regulate
population growth 1260
Population Change and Population Density 1260
Mechanisms of Density-Dependent
Population Regulation 1261
Population Dynamics 1263
CONCEPT 53.6 The human population
is no longer growing exponentially but
is still increasing extremely rapidly 1265
The Global Human Population 1265
Global Carrying Capacity 1267
54 Biodiversity and Communities 1272
CONCEPT 54.1 Interactions between species can help, harm,
or have no effect on the individuals involved 1273
Competition 1273
Exploitation 1275
Positive Interactions 1278
CONCEPT 54.2 Diversity and trophic structure characterize
biological communities 1280
Species Diversity 1280
Diversity and Community Stability 1281
Trophic Structure 1281
Species with a Large Impact 1283
Bottom-Up and Top-Down Controls 1284
CONCEPT 54.3 Disturbance influences species diversity and
composition 1286
Characterizing Disturbance 1286
Ecological Succession 1287
Human Disturbance 1289
CONCEPT 54.4 Biogeographic factors affect community
diversity 1289
Latitudinal Gradients 1290
Area Effects 1290
Island Equilibrium Model 1290
CONCEPT 54.5 Pathogens alter community structure locally
and globally 1292
Effects on Community Structure 1292
Community Ecology and Zoonotic Diseases 1292
55 Energy Flow and Chemical Cycling
in Ecosystems 1296
CONCEPT 55.1 Physical laws govern energy flow and chemical
cycling in ecosystems 1297
Energy Flow and Chemical Cycling 1297
Conservation of Energy 1297
Conservation of Mass 1297
Energy, Mass, and Trophic Levels 1298
CONCEPT 55.2 Energy and other limiting factors control
primary production in ecosystems 1299
Ecosystem Energy Budgets 1299
Primary Production in Aquatic Ecosystems 1300
Primary Production in Terrestrial Ecosystems 1301
Effects of Climate Change on Production 1302
CONCEPT 55.3 Energy transfer between trophic levels is
typically only 10% efficient 1304
Production Efficiency 1304
Trophic Efficiency and Ecological Pyramids 1304
CONCEPT 55.4 Biological and geochemical processes cycle
nutrients and water in ecosystems 1306
Decomposition and Nutrient Cycling Rates 1306
Biogeochemical Cycles 1307
Case Study: Nutrient Cycling in the Hubbard Brook Experimental
Forest 1310
CONCEPT 55.5 Restoration ecologists return degraded
ecosystems to a more natural state 1311
Bioremediation 1311
Biological Augmentation 1313
Ecosystems: A Review 1313
56 Conservation and Global
Ecology 1318
CONCEPT 56.1 Human activities threaten earth’s
biodiversity 1319
Three Levels of Biodiversity 1319
Biodiversity and Human Welfare 1320
Threats to Biodiversity 1321
Can Extinct Species Be Resurrected? 1324
CONCEPT 56.2 Population conservation focuses
on population size, genetic diversity, and critical
habitat 1324
Extinction Risks in Small Populations 1324
Critical Habitat 1327
Weighing Conflicting Demands 1328
CONCEPT 56.3 Landscape and regional conservation help
sustain biodiversity 1328
Landscape Structure and Biodiversity 1328
Establishing Protected Areas 1330
Urban Ecology 1331
CONCEPT 56.4 Earth is changing rapidly as a result of human
actions 1332
Nutrient Enrichment 1332
Toxins in the Environment 1333
Greenhouse Gases and Climate Change 1336
Depletion of Atmospheric Ozone 1341
CONCEPT 56.5 Sustainable development can improve human
lives while conserving biodiversity 1342
Sustainable Development 1342
The Future of the Biosphere 1343
Appendix A Answers A-1
Appendix B Classification Of Life B-1
Appendix C A Comparison Of The Light Microscope And The
Electron Microscope C-1
Appendix D Scientific Skills Review D-1
Credits Cr-1
Glossary G-1
Index I-1