Biological Science, Third Canadian Edition
By Scott Freeman, Kim Quillin, Lizabeth Allison, Michael Black, Greg Podgorski, Emily Taylor, Jeff Carmichael, Michael Harrington and Joan Sharp
Detailed Contents:
1 Biology and the Tree of Life 1
1.1 What Does It Mean to Say That Something Is Alive? 2
1.2 Life Is Cellular 2
All Organisms Are Made of Cells 2
Where Do Cells Come From? 3
Life Replicates through Cell Division 4
1.3 Life Evolves 4
What Is Evolution? 4
What Is Natural Selection? 4
1.4 Life Processes Information 5
The Central Dogma 5
Life Requires Energy 6
1.5 The Tree of Life 6
Using Molecules to Understand the Tree of Life 6
How Should We Name Branches on the Tree of Life? 8
1.6 Doing Biology 9
How Has Artificial Selection Affected Bighorn Sheep? An
Introduction to Hypothesis Testing 9
CANADIAN RESEARCH 1.1 Artificial Selection on Bighorn Sheep in Alberta 10
How Do Ants Navigate? An Introduction to Experimental Design 10
CHAPTER REVIEW 13
Doing Biology 16
BioSkills 18
B.1 Using the Metric System and Significant Figures 19
Significant Figures 19
B.2 Reading and Making Graphs 20
Getting Started 21
Types of Graphs 22
Getting Practice 23
B.3 Interpreting Standard Error Bars and Using
Statistical Tests 23
Standard Error Bars 23
Using Statistical Tests 24
Interpreting P Values and Statistical Significance 24
B.4 Working with Probabilities 25
The Both-And Rule 25
The Either-Or Rule 26
B.5 Separating and Visualizing Molecules 26
Using Electrophoresis to Separate Molecules 26
Using Thin Layer Chromatography to Separate
Molecules 27
Visualizing Molecules 27
B.6 Separating Cell Components by
Centrifugation 29
B.7 Using Microscopy 30
Light and Fluorescence Microscopy 30
Electron Microscopy 30
Studying Live Cells and Real-Time Processes 31
Visualizing Cellular Structures in 3-D 32
B.8 Using Molecular Biology Tools and
Techniques 32
Making and Using DNA Libraries 33
Amplifying DNA Using the Polymerase
Chain Reaction (PCR) 33
Automated Sanger DNA Sequencing 35
Next-Generation DNA Sequencing (NGS) 36
B.9 Using Cell Culture and Model Organisms
as Tools 36
Cell and Tissue Culture Methods 36
Model Organisms 37
B.10 Reading and Making Visual Models 40
Tips for Interpreting Models 40
Tips for Making Your Own Models 40
Concept Maps 41
B.11 Reading and Making Phylogenetic Trees 42
Anatomy of a Phylogenetic Tree 42
How to Read a Phylogenetic Tree 43
How to Draw a Phylogenetic Tree 43
B.12 Reading Chemical Structures 43
B.13 Translating Greek and Latin Roots in Biology 45
B.14 Reading and Citing the Primary Literature 45
What Is the Primary Literature? 45
Getting Started 45
Citing Sources 47
Getting Practice 47
B.15 Recognizing and Correcting Misconceptions 47
B.16 Using Bloom’s Taxonomy for Study Success 48
Categories of Human Cognition 48
Six Study Steps to Success 48
UNIT 1 THE MOLECULAR ORIGIN AND EVOLUTION OF LIFE 50
2 Water and Carbon: The
Chemical Basis of Life 50
2.1 Atoms, Ions, and Molecules: The Building
Blocks of Chemical Evolution 51
Basic Atomic Structure 51
How Does Covalent Bonding Hold Molecules Together? 53
Ionic Bonding, Ions, and the Electron-Sharing Continuum 54
Some Simple Molecules Formed from C, H, N, and O 55
The Geometry of Simple Molecules 55
Representing Molecules 55
2.2 Properties of Water and the Early Oceans 56
Why Is Water Such an Efficient Solvent? 57
What Properties Are Correlated with Water’s Structure? 57
The Role of Water in Acid–Base Chemical Reactions 59
2.3 Chemical Reactions, Energy, and Chemical Evolution 61
How Do Chemical Reactions Happen? 61
What Is Energy? 62
What Makes a Chemical Reaction Spontaneous? 62
2.4 Model Systems for Investigating Chemical
Evolution 64
Early Origin-of-Life Experiments 64
Recent Origin-of-Life Experiments 65
CANADIAN RESEARCH 2.1 Searching for Life in Extreme
Environments 67
2.5 The Importance of Organic Molecules 67
CANADIAN RESEARCH 2.2 The Carbon-Rich Tagish Lake
Meteorite 68
Linking Carbon Atoms Together 68
Functional Groups 68
CHAPTER REVIEW 70
3 Protein Structure and
Function 73
3.1 Amino Acids and Their Polymerization 74
The Structure of Amino Acids 74
The Nature of Side Chains 74
How Do Amino Acids Link to Form Proteins? 76
3.2 What Do Proteins Look Like? 78
Primary Structure 78
CANADIAN RESEARCH 3.1 Designing New Proteins 79
Secondary Structure 80
Tertiary Structure 81
Quaternary Structure 81
3.3 Folding and Function 83
Normal Folding Is Crucial to Function 83
Protein Shape Is Flexible 83
Canadian Iss ues 3.1 Prion Diseases in Canada 85
3.4 Protein Functions Are as Diverse as Protein
Structures 85
Why Are Enzymes Good Catalysts? 85
Did Life Arise from a Self-Replicating Enzyme? 86
CHAPTER REVIEW 86
4 Nucleic Acids and
the RNA World 89
4.1 What Is a Nucleic Acid? 90
What Are Nucleotides? 90
How Do Nucleotides Polymerize to Form
Nucleic Acids? 91
4.2 DNA Structure and Function 93
What Is the Nature of DNA’s Secondary Structure? 93
The Tertiary Structure of DNA 95
DNA Functions as an Information-Containing Molecule 95
The DNA Double Helix Is a Stable Structure 96
4.3 RNA Structure and Function 97
Structurally, RNA Differs from DNA 97
RNA Is an Information-Containing Molecule 98
RNA Can Function as a Catalytic Molecule 98
4.4 In Search of the First Life-Form 99
How Biologists Study the RNA World 99
The RNA World May Have Sparked the Evolution of Life 100
CANADIAN RESEARCH 4.1 Designing New Deoxyribozymes 100
CHAPTER REVIEW 101
5 An Introduction to
Carbohydrates 103
5.1 Sugars as Monomers 104
What Distinguishes One Monosaccharide from Another? 104
Can Monosaccharides Form by Chemical Evolution? 105
5.2 The Structure of Disaccharides 106
5.3 The Structure of Polysaccharides 107
Starch: A Storage Polysaccharide in Plants 107
Glycogen: A Highly Branched Storage Polysaccharide in
Animals 107
Cellulose: A Structural Polysaccharide in Plants 107
Chitin: A Structural Polysaccharide in Fungi and
Animals 107
Peptidoglycan: A Structural Polysaccharide
in Bacteria 107
Polysaccharides and Chemical Evolution 107
5.4 What Do Carbohydrates Do? 109
Carbohydrates Can Provide Structural Support 109
The Role of Carbohydrates in Cell Identity 109
Carbohydrates and Energy Storage 110
CANADIAN RESEARCH 5.1 Human Milk Carbohydrates 110
Canadian Iss ues 5.1 Natural and Artificial Sweeteners 112
CHAPTER REVIEW 113
6 Lipids, Membranes, and the
First Cells 116
6.1 Lipid Structure and Function 117
Why Is Bond Structure Important? 117
A Look at Three Types of Lipids Found in Cells 118
How Membrane Lipids Interact with Water 119
Were Lipids Present during Chemical Evolution? 120
6.2 Phospholipid Bilayers 120
Artificial Membranes as an Experimental System 120
Selective Permeability of Lipid Bilayers 121
How Does Lipid Structure Affect Membrane Permeability? 121
How Does Temperature Affect the Fluidity and Permeability of
Membranes? 122
6.3 How Substances Move across Lipid Bilayers:
Diffusion and Osmosis 123
CANADIAN RESEARCH 6.1 Artificial Cells and Liposomal
Nanomedicines 124
Diffusion 125
Osmosis 125
Membranes and Chemical Evolution 126
6.4 Proteins Alter Membrane Structure and
Function 127
Development of the Fluid-Mosaic Model 128
Systems for Studying Membrane Proteins 129
Channel Proteins Facilitate Diffusion 129
Carrier Proteins Facilitate Diffusion 132
Pumps and Coupled Transporters Perform Active Transport 133
Plasma Membranes Define the Intracellular Environment 134
CANADIAN RESEARCH 6.2 Membrane Proteins 135
CHAPTER REVIEW 136
Macromolecules 138
CELL STRUCTURE AND FUNCTION 140
UNIT 2 CELL STRUCTURE AND FUNCTION 140
7 Inside the Cell 140
7.1 Bacterial and Archaeal Cell Structures and Their
Functions 141
A Revolutionary New View 141
Prokaryotic Cell Structures: A Parts List 141
CANADIAN RESEARCH 7.1 Bacteria Cells Have Their Own
Cytoskeleton 143
7.2 Eukaryotic Cell Structures and Their
Functions 144
The Benefits of Organelles 145
Eukaryotic Cell Structures: A Parts List 145
7.3 Putting the Parts into a Whole 152
Structure and Function at the Whole-Cell Level 152
The Dynamic Cell 153
7.4 Cell Systems I: Nuclear Transport 154
Structure and Function of the Nuclear Envelope 154
How Do Molecules Enter the Nucleus? 154
7.5 Cell Systems II: The Endomembrane System
Manufactures, Ships, and Recycles Cargo 155
Studying the Pathway through the Endomembrane
System 156
Entering the Endomembrane System: The Signal Hypothesis 157
Moving from the ER to the Golgi Apparatus 158
What Happens Inside the Golgi Apparatus? 159
How Do Proteins Reach Their Destinations? 159
Recycling Material in the Lysosome 159
7.6 Cell Systems III: The Dynamic Cytoskeleton 161
Actin Filaments 162
Intermediate Filaments 163
Microtubules 163
Flagella and Cilia: Moving the Entire Cell 165
CANADIAN RESEARCH 7.2 Pathogenic Bacteria Alter the
Cytoskeleton of Human Cells 166
CHAPTER REVIEW 167
8 Energy and Enzymes:
An Introduction to
Metabolism 170
8.1 What Happens to Energy in Chemical
Reactions? 171
Chemical Reactions Involve Energy Transformations 171
Temperature and Concentration Affect Reaction Rates 172
8.2 Nonspontaneous Reactions May Be Driven Using
Chemical Energy 174
Redox Reactions Transfer Energy via Electrons 174
ATP Transfers Energy via Phosphate Groups 176
8.3 How Enzymes Work 178
Enzymes Help Reactions Clear Two Hurdles 178
What Limits the Rate of Catalysis? 180
Do Enzymes Work Alone? 181
8.4 What Factors Affect Enzyme Function? 181
Enzymes Are Optimized for Particular Environments 181
Most Enzymes Are Regulated 182
CANADIAN RESEARCH 8.1 Insulin Processing by Proprotein
Convertases 184
8.5 Enzymes Can Work Together in Metabolic
Pathways 184
Metabolic Pathways Are Regulated 184
Metabolic Pathways Evolve 185
CHAPTER REVIEW 186
9 Cellular Respiration and
Fermentation 189
9.1 An Overview of Cellular Respiration 190
What Happens When Glucose Is Oxidized? 190
Cellular Respiration Plays a Central Role in Metabolism 191
9.2 Glycolysis: Oxidizing Glucose to Pyruvate 193
Glycolysis Is a Sequence of 10 Reactions 193
How Is Glycolysis Regulated? 193
9.3 Processing Pyruvate to Acetyl CoA 196
9.4 The Citric Acid Cycle: Oxidizing Acetyl CoA to CO2 197
What Happens to the NADH and FADH2? 197
9.5 Electron Transport and Chemiosmosis: Building a
Proton Gradient to Produce ATP 200
The Electron Transport Chain 200
The Discovery of ATP Synthase 201
The Chemiosmosis Hypothesis 203
Organisms Use a Diversity of Electron Acceptors 204
CANADIAN RESEARCH 9.1 The ATP Synthase and Proton Pump 205
9.6 Fermentation 206
Many Different Fermentation Pathways Exist 207
Canadian Iss ues 9.1 Making Biofuels with Fermentation and
Anaerobic Respiration 208
Fermentation as an Alternative to Cellular Respiration 209
CHAPTER REVIEW 209
10 Photosynthesis 212
10.1 Photosynthesis Harnesses Sunlight to Make
Carbohydrate 213
Photosynthesis: Two Linked Sets of Reactions 213
Photosynthesis Occurs in Chloroplasts 214
10.2 How Do Pigments Capture Light Energy? 215
Photosynthetic Pigments Absorb Light 215
When Light Is Absorbed, Electrons Enter an Excited
State 218
10.3 The Discovery of Photosystems I and II 220
How Does Photosystem II Work? 220
How Does Photosystem I Work? 222
The Z Scheme: Photosystems II and I Work Together 223
10.4 How Is Carbon Dioxide Reduced to Produce
Sugars? 225
The Calvin Cycle Fixes Carbon 225
The Discovery of Rubisco 227
How Is Photosynthesis Regulated? 228
Oxygen and Carbon Dioxide Pass through Stomata 228
Mechanisms for Increasing CO2 Concentration 229
CANADIAN RESEARCH 10.1 Photosynthesis in Rice 230
What Happens to the Sugar That Is Produced by
Photosynthesis? 231
CHAPTER REVIEW 232
Energy for Life 234
11 Cell–Cell Interactions 236
11.1 The Cell Surface 237
The Structure and Function of an Extracellular Layer 237
The Extracellular Matrix in Animals 237
CANADIAN RESEARCH 11.1 Collagen Fingerprinting Identifies
Canadian Camels 239
The Cell Wall in Plants 239
11.2 How Do Adjacent Cells Connect and
Communicate? 240
Cell–Cell Attachments in Multicellular Eukaryotes 241
Cells Communicate via Cell–Cell Gaps 244
11.3 How Do Distant Cells Communicate? 246
Cell–Cell Signalling in Multicellular Organisms 246
Signal Reception 246
Signal Processing 246
CANADIAN RESEARCH 11.2 The Discovery of Insulin 249
Signal Response 251
Signal Deactivation 252
11.4 Signalling between Unicellular Organisms 252
CHAPTER REVIEW 253
12 The Cell Cycle 256
12.1 How Do Cells Replicate? 257
What Is a Chromosome? 257
Cells Alternate between M Phase and Interphase 258
The Discovery of S Phase 258
The Discovery of the Gap Phases 258
The Cell Cycle 259
12.2 What Happens during M Phase? 260
Proteins Needed for Mitosis 260
Events in Mitosis 260
How Do Chromosomes Move during Anaphase? 262
Cytokinesis Results in Two Daughter Cells 265
Bacterial Cell Replication 266
12.3 Control of the Cell Cycle 266
The Discovery of Cell-Cycle Regulatory Molecules 267
CANADIAN RESEARCH 12.1 Yoshio Masui and the Discovery of
MPF 268
CANADIAN RESEARCH
12.2 MPF Activates Condensins Directly 269
Cell-Cycle Checkpoints Can Arrest the Cell Cycle 270
12.4 Cancer: Out-of-Control Cell Division 271
Properties of Cancer Cells 271
Causes of Cancer 271
CHAPTER REVIEW 274
Unit 3 GENE STRUCTURE AND EXPRESSION 276
13 Meiosis 276
13.1 How Does Meiosis Occur? 277
Organisms Have Unique Chromosome Compositions 277
The Concept of Ploidy 278
An Overview of Meiosis 279
The Phases of Meiosis I 282
The Phases of Meiosis II 284
A Closer Look at Synapsis and Crossing Over 284
Mitosis versus Meiosis 285
CANADIAN RESEARCH 13.1 The Proteins Required for Prophase I
of Meiosis 287
13.2 Meiosis Promotes Genetic Variation 287
Chromosomes and Heredity 288
The Role of Independent Assortment 288
The Role of Crossing Over 289
How Does Fertilization Affect Genetic Variation? 289
13.3 What Happens When Things Go Wrong in
Meiosis? 290
How Do Mistakes Occur? 290
Why Do Mistakes Occur? 291
13.4 Why Does Meiosis Exist? 292
The Paradox of Sex 292
The Purifying Selection Hypothesis 293
The Changing-Environment Hypothesis 293
CHAPTER REVIEW 294
14 Mendel and the Gene 297
14.1 Mendel’s Experimental System 298
What Questions Was Mendel Trying to Answer? 298
The Garden Pea Served as the First Model Organism in
Genetics 298
14.2 Mendel’s Experiments with a Single Trait 300
The Monohybrid Cross 300
Particulate Inheritance 302
14.3 Mendel’s Experiments with Two Traits 304
The Dihybrid Cross 304
Using a Testcross to Confirm Predictions 306
14.4 The Chromosome Theory of Inheritance 307
Meiosis Explains Mendel’s Principles 307
Testing the Chromosome Theory 307
14.5 Extending Mendel’s Rules 310
Linkage: What Happens When Genes Are Located on the Same
Chromosome? 310
Quantitative Methods 14.1 Linkage and Genetic Mapping 312
How Many Alleles Can a Gene Have? 313
Are Alleles Always Dominant or Recessive? 313
Does Each Gene Affect Just One Trait? 314
Are All Traits Determined by a Gene? 314
Can Mendel’s Principles Explain Traits That Don’t Fall into
Distinct Categories? 315
14.6 Applying Mendel’s Rules to Human Inheritance 317
Identifying Alleles as Recessive or Dominant 317
Identifying Traits as Autosomal or Sex-Linked 318
CANADIAN RESEARCH 14.1 The Genetics of Dog
Coat Colour 319
CHAPTER REVIEW 321
15 DNA and the Gene: Synthesis
and Repair 325
15.1 What Are Genes Made Of? 326
The Hershey–Chase Experiment 326
The Secondary Structure of DNA 327
15.2 Testing Early Hypotheses about DNA
Synthesis 328
Three Alternative Hypotheses 329
The Meselson–Stahl Experiment 329
15.3 A Model for DNA Synthesis 329
Where Does Replication Start? 331
How Is the Helix Opened and Stabilized? 331
How Is the Leading Strand Synthesized? 332
How Is the Lagging Strand Synthesized? 333
15.4 Replicating the Ends of Linear Chromosomes 336
The End Replication Problem 336
Telomerase Solves the End Replication Problem 337
Telomerase Regulation 337
CANADIAN RESEARCH 15.1 Telomerase and Cancer 339
15.5 Repairing Mistakes and DNA Damage 339
Correcting Mistakes in DNA Synthesis 339
Repairing Damaged DNA 340
DNA Repair and the Cell Cycle 341
CANADIAN RESEARCH 15.2 Telomeres and Cancer 341
CHAPTER REVIEW 342
16 How Genes Work 344
16.1 What Do Genes Do? 345
The One-Gene, One-Enzyme Hypothesis 345
An Experimental Test of the Hypothesis 345
16.2 The Central Dogma of Molecular Biology 347
RNA as the Intermediary between Genes and Proteins 347
Dissecting the Central Dogma 347
Linking the Central Dogma to Cellular Processes 348
16.3 The Genetic Code 349
How Long Is a “Word” in the Genetic Code? 349
How Did Researchers Crack the Code? 350
16.4 What Are the Types and Consequences of
Mutation? 352
Point Mutations 352
Chromosome Mutations 354
CANADIAN RESEARCH 16.1 The Mutations Responsible for
Himalayan Fur Colour in Mink and Mice 354
CHAPTER REVIEW 355
17 Transcription, RNA
Processing, and
Translation 358
17.1 An Overview of Transcription 359
Initiation: How Does Transcription Begin in Bacteria? 359
Elongation and Termination 361
Transcription in Eukaryotes 361
17.2 mRNA Processing in Eukaryotes 363
The Startling Discovery of Split Eukaryotic Genes 363
CANADIAN RESEARCH 17.1 RNA Base Modifications 363
RNA Splicing 364
Adding Caps and Tails to Transcripts 364
17.3 An Introduction to Translation 365
Ribosomes Are the Site of Protein Synthesis 365
Translation in Bacteria and Eukaryotes 365
How Does an mRNA Codon Specify an Amino Acid? 366
17.4 The Structure and Function of Transfer RNA 366
What Do tRNAs Look Like? 367
How Are Amino Acids Attached to tRNAs? 368
How Many tRNAs Are There? 369
17.5 The Structure of Ribosomes and Their Function in
Translation 369
Initiating Translation 370
Elongation: Extending the Polypeptide 371
Terminating Translation 371
Post-Translational Modifications 371
CANADIAN RESEARCH 17.2 RNA Synthesis in Mitochondria 373
CHAPTER REVIEW 374
18 Control of Gene Expression
in Bacteria 377
18.1 An Overview of Gene Regulation and Information
Flow 378
Mechanisms of Regulation 378
Metabolizing Lactose—A Model System 379
18.2 Identifying Regulated Genes 380
18.3 Negative Control of Transcription 382
The Operon Model 382
How Does Glucose Regulate the lac Operon? 384
Why Has the lac Operon Model Been So Important? 384
18.4 Positive Control of Transcription 385
18.5 Global Gene Regulation 386
CANADIAN RESEARCH 18.1 Gene Expression in a Pathogenic
Bacteria 387
CHAPTER REVIEW 387
19 Control of Gene Expression
in Eukaryotes 390
19.1 Gene Regulation in Eukaryotes—An Overview 391
19.2 Chromatin Remodelling 391
What Is Chromatin’s Basic Structure? 392
Evidence that Chromatin Structure Is Altered in Active
Genes 393
How Is Chromatin Altered? 393
Chromatin Modifications Can Be Inherited 394
CANADIAN RESEARCH 19.1 Epigenetic Regulation of Ant Size 395
19.3 Initiating Transcription: Regulatory Sequences and
Proteins 396
Promoter-Proximal Elements Are Regulatory Sequences Near
the Core Promoter 396
Enhancers Are Regulatory Sequences Far from the Core
Promoter 396
The Role of Transcription Factors in Differential Gene
Expression 397
How Do Transcription Factors Recognize Specific DNA
Sequences? 397
A Model for Transcription Initiation 398
19.4 Post-Transcriptional Control 400
Alternative Splicing of Primary RNAs 400
How Is Translation Controlled? 400
CANADIAN RESEARCH 19.2 Alternative Splicing of RNAs in
Human Nerve Cells 401
Post-Translational Control 403
19.5 How Does Gene Expression Compare in Bacteria and
Eukaryotes? 403
19.6 Linking Cancer to Defects in Gene Regulation 405
The Genetic Basis of Uncontrolled Cell Growth 405
The p53 Tumour Suppressor: A Case Study 405
CHAPTER REVIEW 406
Genetic Information 408
20 The Molecular Revolution:
Biotechnology and
Beyond 410
20.1 Recombinant DNA Technology 411
Using Plasmids in Cloning 411
Using Restriction Endonucleases and DNA Ligase to Cut and
Paste DNA 411
Transformation: Introducing Recombinant Plasmids into
Bacterial Cells 413
Using Reverse Transcriptase to Produce cDNAs 413
Adding Genes to an Organism 413
Removing Genes from an Organism 414
20.2 The Polymerase Chain Reaction 414
Requirements of PCR 414
DNA Fingerprinting 415
CANADIAN RESEARCH 20.1 Ancient DNA in Canada 415
20.3 DNA Sequencing 417
Bioinformatics 418
Which Genomes Are Being Sequenced, and Why? 418
20.4 Insights from Genome Analysis 418
The Natural History of Prokaryotic Genomes 419
The Natural History of Eukaryotic Genomes 419
Insights from the Human Genome Project 422
Genomics after Genome Projects 422
Canadian Iss ues 20.1 iBOL: The International Barcode of Life
Project 423
20.5 Finding and Engineering Genes 424
What Were Some of the First Human Genes Found? 424
How Are Human Genes Found Today? 425
What Are the Benefits of Finding a Disease Gene? 425
Can Gene Therapy Provide a Cure? 426
20.6 Metagenomics, Functional Genomics, and
Proteomics 427
What Is Metagenomics? 427
What Is Functional Genomics? 427
What Is Proteomics? 427
CHAPTER REVIEW 428
21 Genes, Development,
and Evolution 430
21.1 Shared Developmental Processes 431
Cell Division 431
Cell–Cell Interactions 432
Cell Differentiation 432
Cell Movement and Changes in Shape 433
Programmed Cell Death 433
21.2 Genetic Equivalence and Differential Gene
Expression in Development 433
Evidence that Differentiated Plant Cells Are Genetically
Equivalent 433
Evidence that Differentiated Animal Cells Are Genetically
Equivalent 434
How Does Differential Gene Expression Occur? 435
CANADIAN RESEARCH 21.1 The First Cloned Drosophila 435
21.3 Regulatory Cascades Establish the Body Plan 436
Morphogens Set Up the Body Axes 436
Regulatory Genes Provide Increasingly Specific Positional
Information 438
Regulatory Genes and Signalling Molecules Are Evolutionarily
Conserved 439
CANADIAN RESEARCH 21.2 Stem Cells and Stem Cell–Based
Therapies 441
21.4 Changes in Developmental Gene Expression Drive
Evolutionary Change 443
CHAPTER REVIEW 445
UNIT 4 EVOLUTIONARY PATTERNS AND PROCESSES 447
22 Evolution by Natural
Selection 447
22.1 The Evolution of Evolutionary Thought 448
Plato and Typological Thinking 448
Aristotle and the Scale of Nature 448
Lamarck and the Idea of Evolution as Change through
Time 448
Darwin and Wallace and Evolution by Natural Selection 448
22.2 The Pattern of Evolution: Have Species Changed, and
Are They Related? 449
Evidence for Change through Time 449
Evidence of Descent from a Common Ancestor 452
Evolution’s “Internal Consistency”—The Importance of
Independent Data Sets 455
22.3 The Process of Evolution: How Does Natural
Selection Work? 456
Darwin’s Inspiration 456
Darwin’s Four Postulates 457
The Biological Definitions of Fitness and Adaptation 457
22.4 Evolution in Action: Recent Research on Natural
Selection 458
Case Study 1: How Did Mycobacterium tuberculosis Become
Resistant to Antibiotics? 458
Case Study 2: Why Do Beak Sizes and Shapes Vary in Galápagos
Finches? 460
Canadian Iss ues 22.1 Evolution in Action: Do Hunting and
Fishing Select for Undesirable Traits? 460
22.5 Common Misconceptions about Natural Selection
and Adaptation 463
Natural Selection Does Not Change Individuals 463
Evolution Is Not Goal Directed 464
Limitations of Natural Selection 465
CHAPTER REVIEW 467
23 Evolutionary Processes 469
23.1 Analyzing Change in Allele Frequencies: The Hardy–
Weinberg Principle 470
The Gene Pool Concept 470
Deriving the Hardy–Weinberg Principle 470
The Hardy–Weinberg Model Makes Important
Assumptions 471
How Does the Hardy–Weinberg Principle Serve as a Null
Hypothesis? 472
23.2 Natural Selection 474
How Does Selection Affect Genetic Variation? 474
Mode 1: Directional Selection 474
Mode 2: Stabilizing Selection 475
Mode 3: Disruptive Selection 476
Mode 4: Balancing Selection 477
23.3 Genetic Drift 477
Simulation Studies of Genetic Drift 478
Experimental Studies of Genetic Drift 479
What Causes Genetic Drift in Natural Populations? 480
23.4 Gene Flow 481
Measuring Gene Flow between Populations 481
Gene Flow Is Random with Respect to Fitness 482
23.5 Mutation 483
Mutation as an Evolutionary Mechanism 483
Experimental Studies of Mutation 484
Studies of Mutation in Natural Populations 485
23.6 Nonrandom Mating 486
Inbreeding 486
Assortative Mating 488
Sexual Selection 488
CANADIAN RESEARCH 23.1 Evolution in Action: Kermode Bears
and Newfoundland Moose 489
CHAPTER REVIEW 493
24 Speciation 496
24.1 How Are Species Defined and Identified? 497
The Biological Species Concept 497
The Morphospecies Concept 497
The Ecological Species Concept 498
The Phylogenetic Species Concept 498
Species Definitions in Action: The Case of the Dusky Seaside
Sparrow 500
24.2 Isolation and Divergence in Allopatry 501
Allopatric Speciation by Dispersal 502
Allopatric Speciation by Vicariance 502
24.3 Isolation and Divergence in Sympatry 503
Sympatric Speciation by Disruptive Selection 503
Sympatric Speciation by Polyploidization 505
24.4 What Happens When Isolated Populations Come into
Contact? 507
Reinforcement 507
CANADIAN RESEARCH 24.1 Dolph Schluter Studies New
Species 508
Hybrid Zones 509
New Species through Hybridization 510
CHAPTER REVIEW 512
25 Phylogenies and the History
of Life 514
25.1 Tools for Studying History: Phylogenetic Trees 515
How Do Biologists Estimate Phylogenies? 516
How Can Biologists Distinguish Homology from
Homoplasy? 517
Whale Evolution: A Case Study 518
25.2 Tools for Studying History: The Fossil Record 520
How Do Fossils Form? 521
Limitations of the Fossil Record 522
Life’s Time Line 522
25.3 Adaptive Radiation 525
Why Do Adaptive Radiations Occur? 525
The Cambrian Explosion 527
CANADIAN RESEARCH 25.1 The Burgess Shale: A Window into the
Cambrian Explosion 528
25.4 Mass Extinction 530
How Do Mass Extinctions Differ from Background
Extinctions? 530
The End-Permian Extinction 531
The End-Cretaceous Extinction 531
The Sixth Mass Extinction? 533
CHAPTER REVIEW 533
Evolution 536
Unit 5 THE DIVERSIFICATION OF LIFE 538
26 Bacteria and Archaea 538
26.1 Why Do Biologists Study Bacteria and Archaea? 539
Biological Impact 539
Some Prokaryotes Thrive in Extreme Environments 539
Medical Importance 540
Role in Bioremediation 542
26.2 How Do Biologists Study Bacteria and Archaea? 543
Using Enrichment Cultures 543
Using Metagenomics 544
Investigating the Human Microbiome 544
Evaluating Molecular Phylogenies 545
26.3 What Themes Occur in the Diversification of
Bacteria and Archaea? 546
Genetic Variation through Gene Transfer 546
Morphological Diversity 546
Metabolic Diversity 548
Ecological Diversity and Global Impacts 552
26.4 Key Lineages of Bacteria and Archaea 554
CANADIAN RESEARCH 26.1 Is There a Universal Tree of Life? 555
Bacteria 556
Archaea 556
CHAPTER REVIEW 558
27 Protists 561
27.1 Why Do Biologists Study Protists? 562
Impacts on Human Health and Welfare 562
Ecological Importance of Protists 564
CANADIAN RESEARCH 27.1 How Will Phytoplankton Respond to
Elevated CO2 Levels? 565
27.2 How Do Biologists Study Protists? 567
Microscopy: Studying Cell Structure 567
Evaluating Molecular Phylogenies 568
Discovering New Lineages via Direct Sequencing 568
27.3 What Themes Occur in the Diversification of
Protists? 569
What Morphological Innovations Evolved in Protists? 569
How Do Protists Obtain Food? 573
How Do Protists Move? 575
How Do Protists Reproduce? 576
Life Cycles—Haploid Dominated versus Diploid Dominated 576
27.4 Key Lineages of Protists 579
Amoebozoa 579
Excavata 579
Plantae 579
Rhizaria 579
Alveolata 581
Stramenopila (Heterokonta) 581
CHAPTER REVIEW 581
28 Green Algae and Land
Plants 584
28.1 Why Do Biologists Study Green Algae and Land
Plants? 585
Plants Provide Ecosystem Services 585
Plants Provide Humans with Food, Fuel, Fibre, Building
Materials, and Medicines 586
28.2 How Do Biologists Study Green Algae and Land
Plants? 587
Analyzing Morphological Traits 587
Using the Fossil Record 588
Evaluating Molecular Phylogenies 590
28.3 What Themes Occur in the Diversification of Land
Plants? 591
The Transition to Land, I: How Did Plants Adapt to Dry
Conditions with Intense Sunlight? 591
Mapping Evolutionary Changes on the Phylogenetic Tree 593
The Transition to Land, II: How Do Plants Reproduce in Dry
Conditions? 594
Canadian Iss ues 28.1 Canada’s National Tree Seed Centre 599
The Angiosperm Radiation 602
CANADIAN RESEARCH 28.1 Flowering Plants and Their
Pollinators 604
28.4 Key Lineages of Green Algae and Land Plants 606
Green Algae 606
Nonvascular Plants 608
Seedless Vascular Plants 608
Seed Plants: Gymnosperms and Angiosperms 608
CHAPTER REVIEW 613
29 Fungi 615
29.1 Why Do Biologists Study Fungi? 616
Fungi Have Important Economic and Ecological Impacts 616
Mycorrhizal Fungi Provide Nutrients for Land Plants 617
Saprophytic Fungi Accelerate the Carbon Cycle on Land 618
29.2 How Do Biologists Study Fungi? 618
Analyzing Morphological Traits 619
Evaluating Molecular Phylogenies 622
29.3 What Themes Occur in the Diversification of
Fungi? 623
Fungi Often Participate in Symbioses 623
CANADIAN RESEARCH 29.1 Photosynthetic Carbon Is Transferred
from Stressed to Healthy Plants through Ectomycorrhizal
Networks 627
What Adaptations Make Fungi Such Effective
Decomposers? 628
Variation in Reproduction 629
Four Major Types of Life Cycles 631
29.4 Key Lineages of Fungi 634
Microsporidia 634
Chytrids 635
Zygomycetes 635
Glomeromycota 636
Basidiomycota 636
Ascomycota 636
CHAPTER REVIEW 636
30 An Introduction to
Animals 639
Canadian Iss ues 30.1 The Canadian Healthy Oceans
Network 640
30.1 What Is an Animal? 641
30.2 What Key Innovations Occurred during the Origin of
Animal Phyla? 642
Origin of Multicellularity 644
Origin of Embryonic Tissue Layers and Muscle 645
Origin of Bilateral Symmetry, Cephalization, and the Nervous
System 646
Origin of the Coelom 649
Origin of Protostomes and Deuterostomes 649
Origin of Segmentation 650
30.3 What Themes Occur in the Diversification of
Animals within Phyla? 650
Sensory Organs 651
Feeding 652
Movement 654
Reproduction 655
Life Cycles 656
30.4 Key Lineages of Animals: Non-Bilaterian
Groups 657
Porifera (Sponges) 657
Ctenophora (Comb Jellies) 658
Cnidaria (Jellyfish, Corals, Anemones, Hydroids) 658
CHAPTER REVIEW 659
31 Protostome Animals 661
31.1 What Is a Protostome? 662
The Water-to-Land Transition 663
Modular Body Plans 664
31.2 What Is a Lophotrochozoan? 664
What Is a Flatworm? 667
What Is a Segmented Worm? 668
What Is a Mollusk? 668
CANADIAN RESEARCH 31.1 Canada’s Cambrian Mollusks 671
31.3 What Is an Ecdysozoan? 673
What Is a Nematode? 674
What Are Tardigrades and Velvet Worms? 674
What Is an Arthropod? 674
Arthropod Diversity 677
Arthropod Metamorphosis 681
CHAPTER REVIEW 682
32 Deuterostome Animals 684
32.1 What Is an Echinoderm? 685
The Echinoderm Body Plan 685
Echinoderms Are Important Consumers 686
32.2 What Is a Chordate? 688
The Cephalochordates 689
The Urochordates 689
The Vertebrates 690
32.3 What Is a Vertebrate? 690
32.4 What Key Innovations Occurred during the
Evolution of Vertebrates? 691
Urochordates: Outgroup to Vertebrates 691
First Vertebrates: Origin of the Cranium and Vertebrae 693
Gnathostomes: Origin of the Vertebrate Jaw 693
Origin of the Bony Endoskeleton 696
Tetrapods: Origin of the Limb 696
Amniotes: Origin of the Amniotic Egg 697
Mammals: Origin of Lactation and Fur 698
Reptiles: Origin of Scales and Feathers Made of Keratin 700
Canadian Iss ues 32.1 Alberta during the Mesozoic Era 701
Parental Care 704
Take-Home Messages 704
32.5 The Primates and Hominins 705
The Primates 705
Fossil Humans 705
The Out-of-Africa Hypothesis 709
Have Humans Stopped Evolving? 710
CHAPTER REVIEW 711
33 Viruses 713
CANADIAN RESEARCH 33.1 Viruses in the Oceans 714
33.1 Why Do Biologists Study Viruses? 715
Viruses Shape the Evolution of Organisms 715
Viruses Cause Disease 715
Current Viral Pandemics in Humans: AIDS 716
33.2 How Do Biologists Study Viruses? 717
Analyzing Morphological Traits 718
Analyzing the Genetic Material 719
Analyzing the Phases of Replicative Growth 719
Analyzing How Viruses Coexist with Host Cells 725
33.3 What Themes Occur in the Diversification of
Viruses? 726
Where Did Viruses Come From? 726
Emerging Viruses, Emerging Diseases 726
33.4 Key Lineages of Viruses 728
CHAPTER REVIEW 732
Diversity of Life 734
Unit 6 HOW PLANTS WORK 736
34 Plant Form and Function 736
34.1 Plant Form: Themes with Many Variations 737
The Importance of Surface Area/Volume Relationships 738
The Root System 738
The Shoot System 740
The Leaf 742
CANADIAN RESEARCH 34.1 Does Phenotypic Plasticity of Leaves
Offer Protection against Herbivore Attack? 744
34.2 Plant Cells and Tissue Systems 746
The Dermal Tissue System 746
The Ground Tissue System 748
The Vascular Tissue System 749
34.3 Primary Growth Extends the Plant Body 751
How Do Apical Meristems Produce the Primary Plant
Body? 751
How Is the Primary Root System Organized? 752
How Is the Primary Shoot System Organized? 754
34.4 Secondary Growth Widens Shoots and Roots 754
What Is a Cambium? 755
How Does a Cambium Initiate Secondary Growth? 755
What Do Vascular Cambia Produce? 756
What Do Cork Cambia Produce? 756
The Structure of Tree Trunks 757
CHAPTER REVIEW 758
35 Water and Sugar Transport in
Plants 760
35.1 Water Potential and Water Movement 761
What Is Water Potential? 761
What Factors Affect Water Potential? 761
Working with Water Potentials 762
Water Potentials in Soils, Plants, and the Atmosphere 763
35.2 How Does Water Move from Roots to
Shoots? 765
Movement of Water and Solutes into the Root 765
Water Movement via Root Pressure 766
Water Movement via Capillary Action 767
The Cohesion-Tension Theory 767
35.3 Plant Features That Reduce Water Loss 770
Limiting Water Loss 770
CANADIAN RESEARCH 35.1 Ecological Pressures and the Evolution
of Drought Adaptation in Plants 771
Obtaining Carbon Dioxide under Water Stress 772
35.4 Translocation of Sugars 773
Tracing Connections between Sources and Sinks 773
The Anatomy of Phloem 773
The Pressure-Flow Hypothesis 774
Phloem Loading 775
Phloem Unloading 777
CHAPTER REVIEW 779
36 Plant Nutrition 782
36.1 Nutritional Requirements of Plants 783
Which Nutrients Are Essential? 783
What Happens When Key Nutrients Are in Short Supply? 785
36.2 Soil: A Dynamic Mixture of Living and Nonliving
Components 786
The Importance of Soil Conservation 786
What Factors Affect Nutrient Availability? 788
36.3 Nutrient Uptake 789
Mechanisms of Nutrient Uptake 789
CANADIAN RESEARCH 36.1 Do Belowground Interactions between
Plants and Fungi Influence Aboveground Interactions
between Plants and Pollinators? 791
Mechanisms of Ion Exclusion 793
36.4 Nitrogen Fixation 795
The Role of Symbiotic Bacteria 795
How Do Nitrogen-Fixing Bacteria Infect Plant Roots? 796
36.5 Nutritional Adaptations of Plants 797
Parasitic Plants 797
Epiphytic Plants 797
Carnivorous Plants 798
CHAPTER REVIEW 799
37 Plant Sensory Systems,
Signals, and Responses 801
37.1 Information Processing in Plants 802
How Do Cells Receive and Process an External
Signal? 802
How Do Cells Respond to Cell–Cell Signals? 802
37.2 Blue Light: The Phototropic Response 804
Phototropins as Blue-Light Receptors 804
Auxin as the Phototropic Hormone 805
37.3 Red and Far-Red Light: Germination, Stem
Elongation, and Flowering 808
The Red/Far-Red “Switch” 808
Phytochrome Is a Red/Far-Red Receptor 808
CANADIAN RESEARCH 37.1 Plant Signalling Networks Help
Influence Proper Growth 809
Signals That Promote Flowering 810
37.4 Gravity: The Gravitropic Response 812
The Statolith Hypothesis 812
Auxin as the Gravitropic Signal 813
37.5 How Do Plants Respond to Wind and Touch? 814
Changes in Growth Patterns 814
Movement Responses 814
37.6 Youth, Maturity, and Aging: The Growth
Responses 815
Auxin and Apical Dominance 815
Cytokinins and Cell Division 816
Gibberellins and ABA: Growth and Dormancy 816
Brassinosteroids and Body Size 819
Ethylene and Senescence 820
An Overview of Plant Growth Regulators 821
37.7 Pathogens and Herbivores: The Defence
Responses 823
How Do Plants Sense and Respond to Pathogens? 823
How Do Plants Sense and Respond to Herbivore
Attack? 825
CHAPTER REVIEW 827
38 Plant Reproduction and
Development 830
38.1 An Introduction to Plant Reproduction 831
Asexual Reproduction 831
Sexual Reproduction and the Plant Life Cycle 832
38.2 Reproductive Structures 833
The General Structure of the Flower 833
How Are Female Gametophytes Produced? 835
How Are Male Gametophytes Produced? 836
38.3 Pollination and Fertilization 837
Pollination 837
Canadian Iss ues 38.1 What Is the Effect of Agriculture on Wild
Bee Abundance and Crop Pollination? 837
Fertilization 840
38.4 Seeds and Fruits 841
The Role of Drying in Seed Maturation 841
Fruit Development and Seed Dispersal 842
Seed Dormancy 843
Seed Germination 845
38.5 Embryogenesis and Vegetative Development 846
Embryogenesis 846
Meristem Formation 847
Which Genes Determine Body Axes in the Plant Embryo? 848
Which Genes Determine Leaf Structure and Shape? 848
CANADIAN RESEARCH 38.1 Apoptosis during the Formation of
Plant Leaves 849
38.6 Reproductive Development 851
The Floral Meristem and the Flower 851
The Genetic Control of Flower Structures 851
CHAPTER REVIEW 853
How Vascular Plants Work 856
Unit 7 HOW ANIMALS WORK 858
39 Animal Form and Function 858
39.1 Form, Function, and Adaptation 859
The Role of Fitness Trade-Offs 859
Adaptation and Acclimatization 861
39.2 Tissues, Organs, and Systems: How Does Structure
Correlate with Function? 861
Structure–Function Relationships at the Molecular and Cellular
Levels 862
Tissues Are Groups of Cells That Function as a Unit 862
Organs and Organ Systems 865
39.3 How Does Body Size Affect Animal Physiology? 866
Surface Area/Volume Relationships: Theory 866
Surface Area/Volume Relationships: Data 867
Adaptations That Increase Surface Area 868
39.4 Homeostasis 869
Homeostasis: General Principles 869
The Role of Regulation and Feedback 870
39.5 Thermoregulation: A Closer Look 871
Mechanisms of Heat Exchange 871
Thermoregulatory Strategies 872
Comparing Endothermy and Ectothermy 872
Countercurrent Heat Exchangers 873
CANADIAN RESEARCH 39.1 Freeze-Tolerant Animals 874
CHAPTER REVIEW 875
40 Water and Electrolyte
Balance in Animals 878
40.1 Osmoregulation and Excretion 879
What Is Osmotic Stress? 879
Osmotic Stress in Seawater, in Freshwater, and on Land 879
How Do Electrolytes and Water Move across Cell
Membranes? 881
Types of Nitrogenous Wastes: Impact on Water Balance 881
40.2 Water and Electrolyte Balance in Marine Fishes 882
Osmoconformation versus Osmoregulation in Marine
Fishes 882
How Do Sharks Excrete Salt? 882
CANADIAN RESEARCH 40.1 The Bamfield Marine Sciences Centre
and Research on Shark Osmoregulation 883
40.3 Water and Electrolyte Balance in Freshwater
Fishes 884
How Do Freshwater Fishes Osmoregulate? 884
40.4 Water and Electrolyte Balance in Terrestrial
Insects 885
How Do Insects Minimize Water Loss from the Body
Surface? 885
40.5 Water and Electrolyte Balance in Terrestrial
Vertebrates 887
The Structure of the Mammalian Kidney 887
The Function of the Mammalian Kidney: An Overview 888
Filtration: The Renal Corpuscle 889
Reabsorption: The Proximal Tubule 889
Creating an Osmotic Gradient: The Loop of Henle 890
Regulating Water and Electrolyte Balance: The Distal Tubule
and Collecting Duct 893
Urine Formation in Nonmammalian Vertebrates 894
CHAPTER REVIEW 895
41 Animal Nutrition 898
41.1 Nutritional Requirements 899
Defining Human Nutritional Requirements 899
Meeting Human Nutritional Requirements 899
Canadian Iss ues 41.1 Vitamin D Deficiency in Canada 901
41.2 Capturing Food: The Structure and Function of
Mouthparts 903
Mouthparts as Adaptations 903
A Case Study: The Cichlid Throat Jaw 903
Detecting the Nutritional Value of Food 904
41.3 How Are Nutrients Digested and Absorbed? 905
An Introduction to the Digestive Tract 905
An Overview of Digestive Processes 905
The Mouth and Esophagus 906
The Stomach 908
The Small Intestine 910
The Large Intestine 913
41.4 Nutritional Homeostasis—Glucose as a Case
Study 914
The Discovery of Insulin 914
Insulin’s Role in Homeostasis 914
Diabetes Mellitus Has Two Forms 915
CANADIAN RESEARCH 41.1 Treating Diabetes Mellitus 916
CHAPTER REVIEW 917
42 Gas Exchange and
Circulation 919
42.1 The Respiratory and Circulatory Systems 920
42.2 Air and Water as Respiratory Media 920
How Do Oxygen and Carbon Dioxide Behave in Air? 920
How Do Oxygen and Carbon Dioxide Behave in Water? 921
42.3 Organs of Gas Exchange 922
Physical Parameters: The Law of Diffusion 922
How Do Gills Work? 922
How Do Insect Tracheae Work? 924
How Do Vertebrate Lungs Work? 926
Homeostatic Control of Ventilation 927
42.4 How Are Oxygen and Carbon Dioxide Transported in
Blood? 929
Structure and Function of Hemoglobin 929
CO2 Transport and the Buffering of Blood pH 932
CANADIAN RESEARCH 42.1 Peter Hochachka and Physiological
Adaptation in Animals 933
42.5 Circulation 934
What Is an Open Circulatory System? 935
What Is a Closed Circulatory System? 935
How Does the Heart Work? 937
Patterns in Blood Pressure and Blood Flow 941
CHAPTER REVIEW 943
43 Animal Nervous Systems 945
43.1 Principles of Electrical Signalling 946
Types of Neurons 946
The Anatomy of a Neuron 947
An Introduction to Membrane Potentials 947
How Is the Resting Potential Maintained? 948
Using Electrodes to Measure Membrane Potentials 949
What Is an Action Potential? 949
43.2 Dissecting the Action Potential 950
Distinct Ion Currents Are Responsible for Depolarization and
Repolarization 950
How Do Voltage-Gated Channels Work? 950
How Is the Action Potential Propagated? 951
43.3 The Synapse 954
Synapse Structure and Neurotransmitter Release 954
What Do Neurotransmitters Do? 955
Postsynaptic Potentials 956
CANADIAN RESEARCH 43.1 David Suzuki and the Discovery of the
Genes Encoding Neuron Proteins 958
43.4 The Vertebrate Nervous System 959
What Does the Peripheral Nervous System Do? 959
Functional Anatomy of the CNS 961
How Do Learning and Memory Work? 964
CHAPTER REVIEW 966
44 Animal Sensory Systems 969
44.1 How Do Sensory Organs Convey Information to the
Brain? 970
Sensory Transduction 970
Transmitting Information to the Brain 971
44.2 Mechanoreception: Sensing Pressure Changes 971
How Do Sensory Cells Respond to Sound Waves and Other Forms
of Pressure? 971
Hearing: The Mammalian Ear 972
CANADIAN RESEARCH 44.1 Why Do Wind Farms Kill Bats? 975
The Lateral Line System in Fishes and Amphibians 977
44.3 Photoreception: Sensing Light 978
The Insect Eye 978
The Vertebrate Eye 978
44.4 Chemoreception: Sensing Chemicals 983
Taste: Detecting Molecules in the Mouth 983
Olfaction: Detecting Molecules in the Air 984
44.5 Other Sensory Systems 986
Thermoreception: Sensing Temperature 986
Electroreception: Sensing Electric Fields 987
Magnetoreception: Sensing Magnetic Fields 988
CHAPTER REVIEW 988
45 Animal Movement 991
45.1 How Do Muscles Contract? 992
Early Muscle Experiments 992
The Sliding-Filament Model 992
How Do Actin and Myosin Interact? 993
How Do Neurons Initiate Contraction? 995
45.2 Muscle Tissues 996
Smooth Muscle 996
Cardiac Muscle 997
Skeletal Muscle 997
45.3 Skeletal Systems 999
Hydrostatic Skeletons 1000
Endoskeletons 1001
Exoskeletons 1002
45.4 Locomotion 1003
How Do Biologists Study Locomotion? 1003
CANADIAN RESEARCH 45.1 Tyrannosaur Tails 1005
Size Matters 1006
CHAPTER REVIEW 1008
46 Chemical Signals in
Animals 1011
46.1 Cell-to-Cell Signalling: An Overview 1012
Major Categories of Chemical Signals 1012
Hormone Signalling Pathways 1013
What Makes Up the Endocrine System? 1014
How Do Researchers Identify a Hormone? 1015
A Breakthrough in Measuring Hormone Levels 1015
46.2 How Do Hormones Act on Target Cells? 1016
Hormone Concentrations Are Low, but Their Effects Are
Large 1016
Three Chemical Classes of Hormones 1016
Steroid Hormones Bind to Intracellular Receptors 1017
Polypeptide Hormones Bind to Receptors on the Plasma
Membrane 1018
Why Do Different Target Cells Respond in Different Ways? 1020
46.3 What Do Hormones Do? 1020
How Do Hormones Direct Developmental Processes? 1021
Canadian Iss ues 46.1 Estrogens in the Environment 1023
How Do Hormones Coordinate Responses to Stressors? 1024
How Are Hormones Involved in Homeostasis? 1026
CANADIAN RESEARCH 46.1 Cortisol Mediates Stress in
Wildlife 1026
46.4 How Is the Production of Hormones
Regulated? 1027
The Hypothalamus and Pituitary Gland 1027
Control of Adrenaline by Sympathetic Nerves 1029
CHAPTER REVIEW 1030
47 Animal Reproduction and
Development 1032
47.1 Asexual and Sexual Reproduction 1033
How Does Asexual Reproduction Occur? 1033
Switching Reproductive Modes: A Case History 1033
Mechanisms of Sexual Reproduction: Gametogenesis 1035
47.2 Reproductive Structures and Their Functions 1037
The Male Reproductive System 1037
The Female Reproductive System 1038
47.3 Fertilization and Egg Development 1040
External Fertilization 1040
Internal Fertilization 1040
The Cell Biology of Fertilization 1042
Why Do Some Females Lay Eggs While Others Give
Birth? 1043
47.4 Embryonic Development 1045
Cleavage 1045
Gastrulation 1046
Organogenesis 1047
CANADIAN RESEARCH 47.1 Apoptosis during the Morphogenesis
of Chick Embryos 1049
47.5 The Role of Sex Hormones in Mammalian
Reproduction 1050
Which Hormones Control Puberty? 1050
Which Hormones Control the Menstrual Cycle in
Humans? 1051
47.6 Pregnancy and Birth in Mammals 1054
Gestation and Development in Marsupials 1054
Major Events during Human Pregnancy 1054
How Does the Mother Nourish the Fetus? 1056
Birth 1056
Canadian Iss ues 47.1 Canada’s Assisted Human Reproduction
Act 1057
CHAPTER REVIEW 1058
48 The Immune System in
Animals 1060
48.1 Innate Immunity 1061
Barriers to Entry 1061
The Innate Immune Response 1062
48.2 Adaptive Immunity: Recognition 1064
An Introduction to Lymphocytes 1065
Lymphocytes Recognize a Diverse Array of Antigens 1066
CANADIAN RESEARCH 48.1 Tak Wah Mak and the Discovery of the
T-Cell Receptor 1068
How Does the Immune System Distinguish Self from
Nonself? 1070
48.3 Adaptive Immunity: Activation 1070
The Clonal Selection Theory 1070
T-Cell Activation 1071
B-Cell Activation and Antibody Secretion 1073
48.4 Adaptive Immunity: Response and Memory 1074
How Are Extracellular Pathogens Eliminated? 1074
How Are Intracellular Pathogens Eliminated? 1075
Why Does the Immune System Reject Foreign Tissues and
Organs? 1076
CANADIAN RESEARCH 48.2 Designing Universal Blood for
Donations 1077
Responding to Future Infections: Immunological
Memory 1077
48.5 What Happens When the Immune System Doesn’t
Work Correctly? 1079
Allergies 1079
Autoimmune Diseases 1079
Immunodeficiency Diseases 1079
CHAPTER REVIEW 1080
How Humans Work 1082
Unit 8 ECOLOGY 1084
49 An Introduction to
Ecology 1084
49.1 Levels of Ecological Study 1085
Organismal Ecology 1085
Population Ecology 1086
Community Ecology 1086
Ecosystem Ecology 1086
Global Ecology 1086
CANADIAN RESEARCH 49.1 Salmon Migration in a Warming
World 1086
Conservation Biology Applies All Levels of Ecological
Study 1088
49.2 What Determines the Distribution and Abundance
of Organisms? 1088
Abiotic Factors 1088
Biotic Factors 1088
History Matters: Past Abiotic and Biotic Factors Influence
Present Patterns 1089
Biotic and Abiotic Factors Interact 1090
49.3 Climate Patterns 1092
Why Are the Tropics Warm and the Poles Cold? 1092
Why Are the Tropics Wet? 1092
What Causes Seasonality in Weather? 1092
What Regional Effects Do Mountains and Oceans Have on
Climate? 1094
49.4 Types of Terrestrial Biomes 1095
Natural Biomes 1095
Anthropogenic Biomes 1097
How Will Global Climate Change Affect Terrestrial Biomes? 1098
49.5 Types of Aquatic Biomes 1099
Salinity 1100
Water Depth and Sunlight Availability 1100
Water Flow 1101
Nutrient Availability 1102
How Are Aquatic Biomes Affected by Humans? 1103
CANADIAN RESEARCH 49.2 The Future of Canada’s Lakes
and Wetlands 1105
CHAPTER REVIEW 1107
50 Behavioural Ecology 1109
50.1 An Introduction to Behavioural Ecology 1110
Proximate and Ultimate Causation 1110
CANADIAN RESEARCH 50.1 Do Male Redback Spiders Benefit from
Being Eaten by Their Mates? 1110
Types of Behaviour: An Overview 1112
50.2 Choosing What, How, and When to Eat 1113
Proximate Causes: Foraging Alleles in Drosophila
melanogaster 1113
Ultimate Causes: Optimal Foraging 1113
50.3 Choosing a Mate 1115
Proximate Causes: How Is Sexual Activity Triggered in Anolis
Lizards? 1115
Ultimate Causes: Sexual Selection 1116
50.4 Choosing a Place to Live 1117
Proximate Causes: How Do Animals Navigate? 1117
Canadian Iss ues 50.1 The Whisky Jack: Canada’s National
Bird? 1118
Ultimate Causes: Why Do Animals Migrate? 1119
50.5 Communicating with Others 1121
Proximate Causes: How Do Honeybees
Communicate? 1121
Ultimate Causes: Why Do Honeybees Communicate the Way
They Do? 1122
When Is Communication Honest or Deceitful? 1122
50.6 Cooperating with Others 1124
Kin Selection 1124
Quantitative Methods 50.1 Calculating the Coefficient of
Relatedness 1125
Manipulation 1126
Reciprocal Altruism 1126
Cooperation and Mutualism 1127
Individuals Do Not Act for the Good of the Species 1127
CHAPTER REVIEW 1127
51 Population Ecology 1130
51.1 Distribution and Abundance 1131
Geographic Distribution 1131
Sampling Methods 1132
Quantitative Methods 51.1 Mark–Recapture
Studies 1132
51.2 Demography 1133
Life Tables 1133
Quantitative Methods 51.2 Using Life Tables to Calculate Population
Growth Rates 1135
CANADIAN RESEARCH 51.1 Tyrannosaur Life Tables 1136
The Role of Life History 1137
51.3 Population Growth 1138
Exponential Growth 1138
Logistic Growth 1139
Quantitative Methods 51.3 Using Growth Models to Predict
Population Growth 1140
What Factors Limit Population Size? 1141
51.4 Population Dynamics 1143
Why Do Some Populations Cycle? 1143
How Do Metapopulations Change through Time? 1145
51.5 Human Population Growth 1146
Age Structure in Human Populations 1146
Analyzing Change in the Growth Rate of Human
Populations 1147
51.6 How Can Population Ecology Help Conserve
Biodiversity? 1149
Using Life-Table Data 1149
Preserving Metapopulations 1150
CHAPTER REVIEW 1152
52 Community Ecology 1154
52.1 Species Interactions 1155
Commensalism 1155
Competition 1156
Consumption 1159
Mutualism 1163
52.2 Community Structure 1165
Why Are Some Species More Important than Others in
Structuring Communities? 1165
How Predictable Are Communities? 1167
52.3 Community Dynamics 1168
Disturbance and Change in Ecological Communities 1168
Succession: The Development of Communities after
Disturbance 1169
52.4 Patterns in Species Richness 1172
Predicting Species Richness: The Theory of Island
Biogeography 1173
Quantitative Methods 52.1 Measuring Species
Diversity 1173
Global Patterns in Species Richness 1174
CANADIAN RESEARCH 52.1 Why Is Biodiversity Higher in the
Tropics? 1176
CHAPTER REVIEW 1177
53 Ecosystems and Global
Ecology 1180
53.1 How Does Energy Flow through Ecosystems? 1181
How Efficient Are Autotrophs at Capturing Solar Energy? 1181
What Happens to the Biomass of Autotrophs? 1182
Energy Transfer between Trophic Levels 1184
Global Patterns in Productivity 1186
53.2 How Do Nutrients Cycle through Ecosystems? 1188
Nutrient Cycling within Ecosystems 1188
CANADIAN RESEARCH 53.1 Can Predators Increase Nutrient
Cycling? 1189
Global Biogeochemical Cycles 1191
53.3 Global Climate Change 1195
What Is the Cause of Global Climate Change? 1195
How Much Will the Climate Change? 1196
Biological Effects of Climate Change 1199
Canadian Iss ues 53.1 Insect Outbreaks Result from and
Contribute to Climate Change 1201
Consequences to Net Primary Productivity 1202
CHAPTER REVIEW 1203
54 Biodiversity and Conservation
Biology 1206
54.1 What Is Biodiversity? 1207
Biodiversity Can Be Measured and Analyzed at Several
Levels 1207
How Many Species Are Living Today? 1209
Where Is Biodiversity Highest? 1210
54.2 Threats to Biodiversity 1212
Multiple Interacting Threats 1212
How Will These Threats Affect Future Extinction Rates? 1216
Quantitative Methods 54.1 Species–Area Plots 1217
54.3 Why Is Biodiversity Important? 1219
Biological Benefits of Biodiversity 1219
Ecosystem Services: Economic and Social Benefits of
Biodiversity and Ecosystems 1221
An Ethical Dimension 1222
54.4 Preserving Biodiversity and Ecosystem
Function 1223
Addressing the Ultimate Causes of Loss 1223
Conservation Strategies to Preserve Genetic Diversity, Species,
and Ecosystem Function 1224
Canadian Iss ues 54.1 SARA—Canada’s Species at Risk Act 1226
Take-Home Message 1229
CHAPTER REVIEW 1230
Ecology 1232
APPENDIX A Answers A:1
APPENDIX B Periodic Table of Elements B:1
Glossary G:1
Credits C:1
Index I:1