Life / 6th ed.

Detailed Contents
About the Authors iii
Preface xiii
UNIT 1
From Atoms to Cells
Chapter 1 What Is Life? 1
1.1 Characteristics of Life 2
Organization 2
Energy Use and Metabolism 4
Maintenance of Internal Constancy 5
Reproduction, Growth, and Development 5
Irritability, Adaptation, and Natural Selection 5
1.2 Life Is Diverse 7
Domains and Kingdoms Describe Life 7
Evolution Is the Backbone of Biology 8
1.3 Studying the Natural World 8
Theories Explain Nature 9
Designing Experiments 13
Limitations of Scientific Inquiry 13
Chapter 2 The Chemistry of Life 17
2.1 What Is Matter? 18
Elements 18
Atoms 18
Molecules 19
Chemical Bonds 20
2.2 Water's Importance to Life 24
Solutions 24
Acids and Bases 25
Water and Temperature 26
2.3 Organic Molecules Are Important to Life 27
Carbohydrates 27
Lipids 29
Proteins 31
Nucleic Acids 35
Chapter 3 Cells 39
3.1 Cells Are the Units of Life 40
Discovering the Cellular Basis of Life 41
The Cell Theory Emerges 42
3.2 Variations on the Cellular Theme 43
Bacterial Cells 46
Archaean Cells 47
Eukaryotic Cells 47
3.3 Organelles Divide Labor 48
Organelles Interact to Secrete Substances 50
Lysosomes and Peroxisomes Are Cellular Digestion Centers-And
More 53
Mitochondria Extract Energy from Nutrients 54
Chloroplasts Provide Plant Cells with Nutrients 55
3.4 Origins of Complex Cells 56
Chapter 4 The Cell Surface and Cytoskeleton 59
4.1 The Cell Membrane Controls Cell Function 60
The Structure of a Cell Membrane 61
How Substances Cross Membranes 63
4.2 The Cytoskeleton Supports Cells 69
Microtubules Are Built of Tubulin 69
Microfilaments Are Built of Actin 70
Intermediate Filaments Provide Scaffolding 71
4.3 Cells Interact and Respond to Signals 73
Animal Cell Junctions Are of Several Types 73
Cell Walls Are Dynamic Structures 74
Cellular Adhesion Directs Cell Movements 75
Signal Transduction Mediates Messages 76
Chapter 5 The Energy of Life 81
5.1 Defining Energy 82
Where Does Energy Come From? 83
Energy Is Potential or Kinetic 83
5.2 Laws of Thermodynamics Describe Energy Transfer 85
The First Law of Thermodynamics 85
The Second Law of Thermodynamics 86
5.3 Cells Metabolize Nutrients 87
Building Up and Breaking Down-
Anabolism and Catabolism 87
Energy in Chemical Reactions 88
Chemical Equilibrium 89
Oxidation and Reduction Reactions Link, Forming Electron Transport
Chains 89
5.4 ATP Is Cellular Energy Currency 90
ATP Has High-Energy Phosphate Bonds 90
Cells Couple ATP Formation and Breakdown
to Other Reactions 91
Other Compounds Take Part in Energy Metabolism 91
5.5 Enzymes and Energy 93
Enzymes Speed Biochemical Reactions 94
Cells Control Metabolic Pathways 94
Chapter 6 Photosynthesis 97
6.1 Life Depends on Photosynthesis 98
Photosynthesis Converts Carbon Dioxide to Carbohydrate 98
How Might Photosynthesis Have Evolved? 99
6.2 Cellular Structures Capture Light Energy 101
What Is Light? 101
Pigment Molecules Capture Light Energy 101
Chloroplasts Are the Sites of Photosynthesis 103
6.3 The Light Reactions Begin Photosynthesis 105
Photosystem II Produces ATP 105
Photosystem I Produces NADPH 106
Two Photosystems Extract More Energy Than One 107
6.4 The Carbon Reactions "Fix" Carbon 109
The Calvin Cycle "Fixes" Carbon 109
Experiments Revealed the Steps of the Calvin Cycle 109
6.5 Photosynthetic Efficiency 111
Photorespiration Alters the Calvin Cycle 111
C4 Photosynthesis Decreases Photorespiration 111
CAM Photosynthesis Stores Carbon Dioxide at Night 112
Chapter 7 How Cells Release Energy 117
7.1 Cellular Respiration Is Not the Same as Breathing 118
7.2 Enzymes Transfer Energy from Glucose to ATP 119
An Overview of Glucose Utilization 119
Making and Using ATP 120
7.3 Glycolysis Breaks Down Glucose to Pyruvic Acid 123
The First Half of Glycolysis Activates Glucose 123
The Second Half of Glycolysis Extracts Some Energy 123
7.4 After Glycolysis-In the Presence of Oxygen 123
The Krebs Cycle Produces ATP and NADH 123
The Electron Transport Chain Drives ATP Formation 125
How Many ATPs Can One Glucose Molecule Yield? 127
Factors That Control Cellular Respiration 128
Proteins and Lipids Enter the Energy-Extracting Pathways 128
7.5 After Glycolysis-In the Absence of Oxygen 131
7.6 Possible Origins of the Energy Pathways 133
UNIT 2
Genetics and Biotechnology
Chapter 8 The Cell Cycle 137
8.1 The Balance Between Cell Division and Cell Death 138
8.2 The Cell Cycle 139
Interphase-A Time of Great Activity 140
Mitosis Distributes Chromosomes 141
Cytokinesis Distributes Other Cell Contents 144
8.3 Cell Cycle Control 145
Checkpoints Keep the Cell Cycle on Track 145
Telomeres Provide a Cellular Clock 146
Signals to Divide 147
Control at the Tissue Level-Stem Cells
and Cell Populations 149
8.4 Cell Death Is a Part of Life 150
Apoptosis Is Programmed Cell Death 150
Why Cells Die 151
8.5 Cancer-When the Cell Cycle Goes Awry 152
Cancer Cells Differ from Normal Cells 152
Causes of Cancer 153
Chapter 9 Meiosis 157
9.1 Why Reproduce? 159
9.2 Variations on the Sexual Reproduction Theme 160
9.3 Meiosis Halves the Chromosome Number 162
9.4 The Sculpting of Gametes 167
Sperm Development 168
Ovum Development 170
Chapter 10 How Inherited Traits Are Transmitted 177
10.1 Tracing the Inheritance of One Gene 178
Experiments with Peas 178
How Biologists Describe Single Genes 180
Mendel's First Law Reflects Meiosis 181
Pedigrees Show Modes of Inheritance 184
10.2 Tracing the Inheritance of Two Genes 186
10.3 How Gene Expression Can Appear to Alter
Mendelian Ratios 188
Allele Interactions 189
Environmental Influences 192
Genetic Heterogeneity-More Than One Way to Inherit a Trait 193
10.4 Polygenic and Multifactorial Traits 194
Measuring the Input of Genes and the Environment 194
Separating Genetic from Environmental Influences 196
Chapter 11 Chromosomes 201
11.1 Chromosome Structure 203
Distinguishing Chromosomes 203
Artificial Chromosomes 203
11.2 "Linking" Mendel's Laws to Chromosomes 204
Experiments Reveal That Genes Are Linked on Chromosomes 204
Linkage Maps 206
11.3 How Chromosomes Determine Sex 206
A Diversity of Sex Determination Mechanisms 206
Sex Determination in Humans 207
11.4 Inheritance of Genes on Sex Chromosomes 208
X-Linked Recessive Inheritance 208
X Inactivation-Equalizing the Sexes 211
11.5 When Chromosomes Are Abnormal 213
Extra Chromosome Sets-Polyploidy 213
Extra and Missing Chromosomes-Aneuploidy 213
Smaller-Scale Chromosome Abnormalities 216
Chapter 12 DNA Structure and Replication 221
12.1 Experiments Identified the Genetic Material 222
DNA Transmits Traits 223
The Genetic Material-DNA, Not Protein 224
Deciphering the Structure of DNA 225
12.2 DNA Is a Double Helix 226
12.3 DNA Replication Maintains Genetic Information 230
Demonstrating Semiconservative DNA Replication 230
Steps and Participants in DNA Replication 235
12.4 DNA Repair 237
Chapter 13 Gene Function 243
13.1 Expressing Genes 244
Bacteria Use Operons to Turn Genes On or Off 245
Multicellular Organisms Use Transcription Factors to Turn Genes On
or Off 245
Steps of Transcription 246
13.2 RNA Orchestrates Protein Synthesis 248
Types of RNA 248
RNA Is Processed 248
13.3 Building a Protein 250
The Genetic Code Connects Gene to Protein 250
Steps of Protein Synthesis 252
Protein Folding Revisited 253
13.4 Mutation-Genetic Misinformation 255
Discovering Mutation in Sickle Cell Disease 255
What Causes Mutation? 255
Types of Mutations 257
Natural Protection Against Mutation 260
13.5 The Human Genome Sequence Reveals
Unexpected Complexity 260
Genome Economy: Reconciling Gene and Protein Number 261
What Does the Other 98.5 Percent of the Human Genome Do? 261
UNIT 3
Evolution
Chapter 14 The Evolution of Evolutionary Thought 269
14.1 Evolution-How Life Works 270
Explaining Life's Diversity 271
Clues in the Earth 273
14.2 Charles Darwin's Voyage 274
Darwin's Observations 274
After the Voyage 276
The Origin of Species and Response to It 276
Natural Selection-The Mechanism 277
14.3 Evolution Today-Epidemiology 279
Emerging Infectious Diseases 279
Evolving Ebola Virus Causes Infectious Illness 281
The Rise of Antibiotic Resistance 281
Chapter 15 The Forces of Evolutionary Change-Microevolution 285
15.1 Evolution is Highly Probable 287
Conditions for Evolution Not to Happen: Hardy-Weinberg
Equilibrium 287
Conditions That Cause Evolutionary Change 287
15.2 Mate Choice and Evolution 289
Nonrandom Mating 289
Migration 289
Genetic Drift 291
15.3 Mutation Fuels Evolution 292
15.4 Natural Selection Molds Evolution 292
Types of Natural Selection 292
Balanced Polymorphism 293
Chapter 16 Speciation and Extinction 299
16.1 The Species Concept 300
The Evolving Species Concept 301
Tree Diagrams Describe the Comings and Goings of Species 302
Morphology Versus Molecules-What Is a Platypus? 303
16.2 Reproductive Differences Distinguish Species 304
Early Obstacles 304
Later Obstacles 304
16.3 Speciation and Space 306
Allopatric Speciation Reflects a Geographic Barrier 306
Parapatric Speciation Occurs in Neighboring Regions 306
Sympatric Speciation Occurs in a Shared Habitat 307
Chromosome Number Contributes to Speciation 308
Difficulties in Examining Speciation and Space 309
16.4 Speciation and Time 310
Evolution May Be Gradual or Proceed by "Leaps and Starts" 310
Bursts of Speciation-Adaptive Radiation 312
16.5 Extinctions 313
Extinctions on a Small Scale 313
What Causes Mass Extinctions? 314
Chapter 17 Evidence of Evolution 321
17.1 Reconstructing the Stories of Life 322
Clues in the Earth and in Molecules 322
Systematics Assembles the Stories of Life 323
17.2 Fossils Record Evolution 327
The Role of Geology in Interpreting Fossil Evidence 327
How Fossils Form 328
Estimating the Age of a Fossil 331
17.3 Comparing Structures 333
Comparing Anatomical Parts Can Reveal
Evolutionary Relationships 334
Vestigial Structures Reflect the Past 334
Embryos Provide Evolutionary Clues 336
17.4 Molecules Reveal Relatedness 337
Comparing Chromosomes 338
Comparing Protein Sequences 339
Comparing DNA Sequences 339
Molecular Clocks 340
Reconciling Fossil, Biogeographical, and Molecular Evidence 341
Chapter 18 The Origin and History of Life 345
18.1 Life's Origins 347
Setting the Scene 347
Prebiotic Simulation Experiments Show How Life Might Have Arisen 348
An RNA World May Have Preceded Cellular Life 350
The Origin of Metabolism 352
18.2 Highlights in the History of Life 352
Cells Emerged and Evolved in the Archean and Proterozoic Eras 354
The Strange Ediacarans Preceded the Cambrian Explosion 356
Life "Exploded" in the Paleozoic Era 357
Reptiles and Flowering Plants Thrived During the Mesozoic Era 361
18.3 The Age of Mammals 362
Mammals Radiated During the Cenozoic Era 362
The Hominoids and Hominids 363
UNIT 4
The Diversity of Life
Chapter 19 Viruses 369
19.1 Viruses-Discovery and Structure 370
The Discovery of Viruses 370
Studying Viruses 371
Viral Structure 371
19.2 Viruses Infect Cells to Reproduce 373
Viruses Bind Target Cells and Introduce
Their Genetic Material 373
Two Viral Lifestyles: Lysis and Lysogeny 375
19.3 Viruses Can Kill Cells 377
Viruses Infect Specific Cells of Certain Species 378
Defenses Against Viral Infections 380
19.4 Other Infectious Agents 380
A Viroid Is an Infectious RNA Molecule 380
A Prion Is One Protein That Takes Variant Forms 381
Chapter 20 Bacteria and Archaea 387
20.1 Prokaryotes Are a Biological Success Story 388
20.2 Parts of a Prokaryotic Cell 389
Internal Structures 390
External Structures 390
20.3 How Microbiologists Distinguish
and Describe Prokaryotes 392
Traditional Methods of Classifying Prokaryotes 392
Molecular Data Reveal Evolutionary Relationships 394
Bacteria and Archaea Revisited 394
20.4 Prokaryotes Transfer Genes Vertically and Horizontally 396
Binary Fission Provides Vertical Gene Transfer 396
Horizontal Gene Transfer Occurs by Three Routes 396
20.5 How Prokaryotes Affect Humans 398
Bacterial Infections in Humans 399
Bacteria as Bioweapons 400
Industrial Microbiology Borrows Prokaryotes' Products and
Processes 400
Chapter 21 Protista 405
21.1 Kingdom Protista Lies at the Crossroads Between the Simpler and the
Complex 406
21.2 Basal Eukaryotes Represent the Most Ancient Protista 407
Basal Eukaryotes That Lack Mitochondria 408
Basal Eukaryotes with Mitochondria 409
21.3 The Alveolates Include Dinoflagellates, Apicomplexa,
and Ciliates 412
Dinoflagellates 412
Apicomplexa 413
Ciliates 415
21.4 The Stramenopiles Include Water Molds, Diatoms, and Some Algae 418
Water Molds 418
Diatoms 418
Brown and Golden Algae 419
21.5 The Red Algae Contain Unique Photosynthetic Pigments 419
21.6 The Green Algae 420
Chapter 22 Plantae 425
22.1 Introducing the Plants 426
Distinguishing Features of Plants 427
Origin and Evolution of Land Plants 428
22.2 Bryophytes Are the Simplest Plants 429
Bryophyte Characteristics and Life Cycle 430
Bryophyte Diversity 431
22.3 Seedless Vascular Plants 432
Seedless Vascular Plant Characteristics and Life Cycle 432
Seedless Vascular Plant Diversity 434
22.4 Seed-Producing Vascular Plants 435
Gymnosperms Are "Naked Seed" Plants 436
Angiosperms Are Flowering Plants 439
Chapter 23 Fungi 445
23.1 Introducing the Fungi 446
Distinguishing Features of Fungi 446
Parts of a Fungus 448
The Place of Fungi in Life History 449
23.2 Chytridiomycetes Are Flagellated Fungi 450
23.3 Zygomycetes Are Prolific, Nonseptate Fungi 450
23.4 Ascomycetes Are Sac Fungi 452
23.5 Basidiomycetes Are Club Fungi 453
23.6 Fungi Interact with Other Organisms 455
Mycorrhizal Fungi Live on or in Roots 455
Lichens Are Distinctive Dual Organisms 456
Ants, Bacteria, and Fungi 458
Chapter 24 Animalia I-Sponges Through Echinoderms 461
24.1 Introducing the Animals 462
24.2 Distinguishing Features of Animals 463
Animals Obtain Nutrients from Others 463
Body Complexity and Form 463
Animal Reproduction and Development 464
24.3 The Sponges (Porifera) Are the Simplest Animals 467
24.4 Cnidarians Are Radially Symmetrical, Aquatic Invertebrates 469
Characteristics of Cnidarians 469
A Closer Look at Corals 471
24.5 Flatworms (Platyhelminthes) 471
24.6 Mollusks Include Clams, Snails, Octopuses, and Squids 473
24.7 Annelids Are Segmented Worms 475
24.8 Roundworms (Nematoda) 477
24.9 Arthropods Include Insects, Crustaceans, and Arachnids 478
Arthropod Characteristics and Organ Systems 478
Arthropod Diversity 479
24.10 The Echinoderms: Life Based on Five-Part Symmetry 481
Echinoderm Characteristics 481
Echinoderm Evolution and Development 483
Chapter 25 Animalia II-The Chordates 489
25.1 Introducing the Chordates 490
25.2 Tunicates and Lancelets Are "Protochordates" 491
Tunicates 491
Lancelets 492
25.3 Vertebrates 495
25.4 Fishes-Vertebrate Life in the Waters 495
Jawless Fishes 495
Jawed Fishes 496
25.5 Amphibians Lead a Dual Lifestyle 499
Amphibian Characteristics 500
Amphibian Diversity 500
25.6 The Reptiles Fully Conquer Land 501
25.7 Birds-Vertebrate Life in the Sky 504
25.8 Mammals Are Furry Milk-Drinkers-And More 507
UNIT 5
Plant Life
Chapter 26 Plant Form and Function 513
26.1 Plant Tissue and Cell Types 514
Meristems 515
Ground Tissue 516
Dermal Tissue 517
Vascular Tissue 518
26.2 Anatomy of a Plant 520
Stems 521
Leaves 522
Roots 526
26.3 Secondary Plant Growth 529
Vascular Cambium 529
Cork Cambium 532
Chapter 27 Plant Nutrition and Transport 535
27.1 Evolution of Complex Transport Systems 536
27.2 Plant Nutrition 536
Essential Nutrients for Plants 537
Nutrients Come from the Atmosphere and Soil 539
Roots Tap Water and Dissolved Minerals 540
How Plants Obtain Nitrogen 541
27.3 Water and Dissolved Minerals Are Pulled Up
to Leaves 541
Water Vapor Is Lost Through Transpiration 542
Water Moves Through Xylem 542
Water Enters Plants in Roots 544
27.4 Photosynthate Is Pushed to Heterotrophic Cells 545
Phloem Sap Composition 545
The Pressure Flow Theory Explains Photosynthate Distribution 545
Chapter 28 Reproduction of Flowering
Plants 549
28.1 Asexual Reproduction 550
28.2 Sexual Reproduction 551
Flowers Are Reproductive Organs 554
Gamete Formation 554
Pollination Brings Pollen to the Stigma 555
Double Fertilization Yields Zygote and Endosperm 560
28.3 Seeds and Fruits 561
Seed Development and Dormancy 561
Fruit Formation 562
Seed Dispersal and Germination 562
Chapter 29 Plant Responses to Stimuli 569
29.1 How Hormones Influence Plant Growth 570
Auxins 571
Gibberellins 572
Cytokinins 573
Ethylene 574
Abscisic Acid 574
29.2 How Plants Move 574
Phototropism-Response to Unidirectional Light 575
Gravitropism-Response to Gravity 575
Thigmotropism-Response to Touch 576
Nastic Movements 576
29.3 How Plants Respond to Seasonal Changes 579
Flowering Is a Response to Photoperiod 579
Do Plants Measure Day or Night? 580
Phytochrome Is a Pigment That Controls Photoperiodism 581
Photoperiod and Phytochrome Influence Other Responses 582
Senescence and Dormancy 583
29.4 Plant Circadian Rhythms 583
Control of Circadian Rhythms 584
Solar Tracking Is a Circadian Rhythm 584
UNIT 6
Animal Life
Chapter 30 Animal Tissues and Organ Systems 589
30.1 Animal Tissue Types 590
Cells Specialize and Associate to Form Tissues 590
Epithelial Tissue Forms Layers 591
Connective Tissues Include Blood, Bone, and Cartilage 593
Nervous Tissue Connects and Integrates the Body 593
Muscle Tissue Provides Movement 595
30.2 Tissues and Organs Build Animal Bodies 595
Tissues and Organs Increased in Complexity with Evolution 595
The Organ Systems of a Human 595
30.3 Organ System Interaction Promotes Homeostasis 597
30.4 A Sample Organ System-The Integument 598
A Closer Look at Human Skin 598
Specializations of the Integument 601
Chapter 31 The Nervous System 607
31.1 The Nervous System Maintains Homeostasis 608
31.2 Neurons Are Functional Units of a Nervous System 609
Anatomy of a Neuron 609
A Neuron at Rest Has a Negative Charge 610
A Neuron Transmitting an Impulse Undergoes a Wave
of Depolarization 612
A Fatty Sheath Speeds Impulse Conduction 612
31.3 Neurotransmitters Pass the Message from Cell to Cell 614
Types of Neurotransmitters and Neuromodulators 615
Neurotransmitter Action at the Synapse 615
Disposal of Neurotransmitters 617
A Neuron Integrates Incoming Messages 618
31.4 Evolutionary Trends in Nervous Systems 619
Invertebrates Have Nerve Nets, Ladders, or Simple Brains 619
Vertebrates Have Central and Peripheral Nervous Systems 620
31.5 The Human Central Nervous System 621
The Spinal Cord 621
Major Brain Regions 622
The Cerebrum Houses the "Mind" 625
Memory 627
31.6 The Human Peripheral Nervous System 629
The Somatic Nervous System 629
The Autonomic Nervous System 629
31.7 Protection of the Nervous System 629
Chapter 32 The Senses 635
32.1 Sensory Systems Are Adaptive 636
32.2 Diverse Sensory Systems Operate by the Same General Principles 638
Sensory Receptors Detect, Transduce, and Amplify Stimuli 638
Sensory Adaptation 638
Types of Sensory Receptors 638
32.3 Chemoreception 640
Chemoreception in Invertebrates 640
Chemoreception in Vertebrates 640
32.4 Photoreception 642
Photoreception in Invertebrates 643
Photoreception in Vertebrates 643
32.5 Mechanoreception 647
Mechanoreception in Invertebrates 647
Mechanoreception in Vertebrates 648
Chapter 33 The Endocrine System 655
33.1 Hormones Are Chemical Messengers and Regulators 656
Roles of Endocrine Systems 656
Components of Endocrine Systems 657
33.2 How Hormones Exert Their Effects 657
Peptide Hormones Bind to Cell Surface Receptors 657
Steroid Hormones Bind to Receptors Inside Cells 658
Feedback Loops Control Hormone Levels 659
33.3 Diversity of Endocrine Systems 660
Hormones in Invertebrates 660
Hormones and Glands in Vertebrates 661
33.4 A Closer Look at the Endocrine System in Humans 663
The Pituitary Is Two Glands in One 663
Glands That Regulate Metabolism 666
Endocrine Control of Reproduction 670
33.5 Prostaglandins Provide Localized Control 671
Chapter 34 The Musculoskeletal System 673
34.1 A Musculoskeletal System Helps an Animal Respond to Its Environment 674
34.2 Types of Skeletons 675
Hydrostatic Skeletons Consist of Constrained Fluid 675
Exoskeletons Protect from the Outside 675
Endoskeletons Support, Protect, and Provide Movement 676
34.3 Muscle Diversity 682
34.4 Vertebrate Muscles 683
Muscle Cell Types 683
Skeletal Muscle Consists of Fiber Bundles 685
Sliding Filaments Generate Movement 688
Whole Muscle Responses to Stimuli 690
34.5 Skeletal Muscle and Bone Function Together 690
Joints-Where Bone Meets Bone 690
Exercise Strengthens Muscles and Bones 692
Chapter 35 The Circulatory System 695
35.1 Circulatory Systems Deliver Nutrients and Remove Wastes 696
Circulatory Systems Are Open or Closed 696
Respiratory Pigments Carry Additional Oxygen 697
Vertebrate Circulatory Systems Are Closed, with Specialized Blood
Cells 697
35.2 The Human Circulatory System 698
The Human Heart Is a Powerful Pump 699
Blood Vessels 701
Blood Pressure 704
Blood Is a Complex Mixture 706
The Effects of Exercise 710
35.3 The Lymphatic System Maintains Circulation and Protects Against
Infection 711
Chapter 36 The Respiratory System 715
36.1 Respiration Exchanges Gases 716
What Is Respiration? 716
Body Surface 717
Tracheal Systems 717
Gills 718
Lungs 718
36.2 Components of the Respiratory System in Humans 721
Respiratory System Structures Transport Air 721
Alveoli Are the Sites of Gas Exchange 725
36.3 Functions of the Respiratory System in Humans 726
How We Breathe 726
Delivering Oxygen and Removing Carbon Dioxide 726
Carbon Monoxide Poisoning 727
36.4 Control of Respiration 728
Blood CO2 Levels Regulate Breathing Rate 728
Breathing at High Altitudes 728
Chapter 37 Digestion and Nutrition 731
37.1 The Art and Evolution of Eating 732
37.2 Digestive Diversity 734
Types of Digestion 734
Digestive System Adaptations 735
37.3 The Digestive System in Humans 736
The Mouth and the Esophagus-Digestion Begins 737
The Stomach Stores, Digests, and Pushes Food 740
The Small Intestine Absorbs Nutrients 741
The Large Intestine Completes Nutrient Absorption 744
The Pancreas, Liver, and Gallbladder Aid Digestion 744
37.4 Human Nutrition 745
Types of Nutrients 745
Nutrient Deficiencies 748
Chapter 38 Regulation of Temperature
and Body Fluids 751
38.1 How Animals Regulate Their Temperature 752
Body Heat Is External or Internal, Body Temperature Constant or
Variable 752
Adaptations to Cold 753
Adaptations to Heat 754
38.2 How Animals Regulate Water and Ion Balance 756
38.3 How Animals Rid Themselves of Nitrogenous Wastes 757
38.4 The Human Urinary System 759
The Kidneys 759
Nephrons 759
38.5 Control of Kidney Function 763
Chapter 39 The Immune System 767
39.1 The Evolution of Immunity 768
Invertebrate Immunity Is Innate Only 769
Vertebrate Immunity Is Innate and Adaptive 770
39.2 Innate Defenses Are Nonspecific and Act Early 771
39.3 Adaptive Defenses Are Specific and Act Later 773
Antigen-Presenting Cells Begin the Immune Response 773
B Cells Produce Antibodies 774
T Cells Stimulate, Secrete, Attack, and Coordinate 777
39.4 The Human Immune System Throughout Life 781
39.5 The Unhealthy Immune System 783
Immunity Breakdown 783
Autoimmunity-Attacking Self 783
Allergies Misdirect the Immune Response 785
Chapter 40 Human Reproduction
and Development 789
40.1 From Embryology to Developmental Biology:
A Descriptive Science Becomes Experimental 790
Does a Fertilized Ovum Contain a Tiny Organism? 791
Early Experiments with Embryos 792
Selective Gene Activation Sculpts Specialized Cell Types 793
40.2 The Human Reproductive System 795
The Human Male Reproductive System 795
The Human Female Reproductive System 798
40.3 The Structures and Stages of Human
Prenatal Development 800
Fertilization Joins Genetic Packages 800
Cleavage-Cells Rapidly Divide 801
Implantation Establishes Pregnancy 802
Gastrulation-Tissues Begin to Form 803
Organogenesis-The Human Body Takes Shape 803
Structures That Support the Embryo 805
The Fetal Period-Structures Are Elaborated 806
Labor and Birth 807
40.4 Growth and Development After Birth 810
The Early Years 810
Aging Is Passive and Active 811
The Human Life Span 812
UNIT 7
Behavior and Ecology
Chapter 41 Animal Behavior 815
41.1 Genes and Experience Shape Behavior 816
Innate Behavior Is Inborn 817
Learned Behavior Results from Experience 819
41.2 Types of Behavior 821
Orientation and Navigation 821
Aggression 823
Mating Behavior 825
Altruism 826
41.3 Animals Living Together 828
Group Living Has Advantages and Disadvantages 828
Environmental Conditions Influence Behavior 829
Communication Keeps the Group Together 830
41.4 Three Animal Societies 832
Snapping Shrimp 832
Naked Mole Rats 833
Honeybees 833
Chapter 42 Populations 837
42.1 A Population Is All Individuals of a Single Species
in a Particular Place 838
Ecology Is the Study of Organisms and Their Environment 838
Characteristics of Populations 839
42.2 How Populations Grow 841
Reproductive Characteristics Influence Population Growth 841
Growth Is Exponential When Resources Are Unlimited 843
42.3 Factors That Limit Population Size 844
Population Growth Eventually Slows 845
Crowding, Competition, Predation, and Pathogens Limit
Population Size 845
Environmental Disasters Kill Irrespective
of Population Size 846
"Boom and Bust" Cycles 847
Influences of Natural Selection on Population Growth 847
42.4 Human Population Growth 849
Chapter 43 Communities and Ecosystems 853
43.1 A Community Includes All Life in an Area 855
Interspecific Competition Prevents Species from Occupying the Same
Niche 855
Other Community Interactions Include Symbiosis
and Predation 856
43.2 Communities Change Over Time 859
Primary Succession-A New Community Arises 859
Secondary Succession-Replacing a Disturbed Community 859
Succession Can Be Complex 860
43.3 An Ecosystem Is a Community
and Its Physical Environment 861
Characteristics of Ecosystems 861
Energy Flows Through an Ecosystem 862
Ecological Pyramids Describe Ecosystem Characteristics 865
43.4 How Chemicals Cycle Within Ecosystems-
Biogeochemical Cycles 866
The Water Cycle 867
The Carbon Cycle 867
The Nitrogen Cycle 867
The Phosphorus Cycle 868
Some Chemicals Become Concentrated as They Ascend Food Webs 869
43.5 A Sampling of Ecosystems 873
The Sea Surface Microlayer 873
Vernal Pools 874
Niagara Escarpment 874
Fjords-Where Fresh Water Meets Seawater 874
Chapter 44 Biomes and Aquatic Ecosystems 877
44.1 Biomes 878
Climate Influences Biomes 879
Tropical Rain Forest 881
Tropical Dry Forest 882
Tropical Savanna 883
Desert 884
Temperate Grasslands 885
Temperate Forests 886
Taiga 887
Tundra 888
44.2 Freshwater Ecosystems 889
Lakes and Ponds 889
Rivers and Streams 890
44.3 Marine Ecosystems 891
Coasts 891
Oceans 893
Chapter 45 Environmental Challenges 897
45.1 Sustainability 899
45.2 The Air 900
Air Pollution 900
Acid Deposition 901
Thinning of the Ozone Layer 902
Global Warming 903
45.3 The Land 905
Deforestation 905
Desertification 906
45.4 The Waters 906
Chemical Pollution 906
Physical Alteration of Waterways 908
Endangered Estuaries 909
Coral Reefs 909
Polluted Oceans 910
45.5 Loss of Biodiversity 911
Biodiversity and Ecosystem Stability 911
Invasion Biology and Introduced Species 911
The Resiliency of Life 912
Appendix A
Units of Measurement 915
Appendix B
Periodic Table of Elements 917
Appendix C
Amino Acid Structures 918
Appendix D
Taxonomy 919
Appendix E
Answers to Genetics Problems 921
Glossary 922
Credits 946
Index 951