BIOSPHERE The Realm of Life

SECOND EDITION

ROBERT A. WALLACE UNIVERSITY OF FLORIDA

JACK L. KING

GERALD P. SANDERS

SCOTT, FORESMAN AND COMPANY GLENVIEW, ILLINOIS

BOSTON LONDON

CONTENTS IN BRIEF

PARTI SCIENCE AND THE ONGOING FLOW OF LIFE I 1 SCIENCE AND ITS DESCENT 2

2 THE BASIC CHEMISTRY OF LIFE 17

3 THE MOLECULES OF LIFE 31

4 THE STRUCTURE AND FUNCTION OF CELLS 45

5 CELL TRANSPORT 68

6 ENERGY AND THE CELL 78

7 PHOTOSYNTHESIS 96

8 GLYCOLYSIS AND RESPIRATION 114

9 MITOSIS AND CELL DIVISION 128

10 MEIOSIS AND SHUFFLING^ CHROMOSOMES 144

PART II GENETICS AND EVOLUTION: History and Horizons 157

11 GREGOR MENDEL AND THE FOUNDATIONS OF GENETICS 158

12 HOW GENES EXPRESS THEMSELVES 173

13 GENES AND CHROMOSOMES 185

14 WHAT IS DNA? 201

15 DNA IN ACTION 218

16 FRONTIERS IN MOLECULAR BIOLOGY 241

17 PRINCIPLES OF EVOLUTION 257

18 EVOLUTION IN POPULATIONS 271

19 EVOLUTION AND THE ORIGIN OF SPECIES 288

PART III FROM PROKARYOTES TO PLANTS 311

20 BACTERIA, VIRUSES, AND THE ORIGIN OF LIFE 312

21 PROTISTS AND FUNGI: THE SIMPLER EUKARYOTES 332

22 EVOLUTION AND DIVERSITY IN PLANTS 358

23 REPRODUCTION IN THE FLOWERING PLANTS 373

24 GROWTH AND ORGANIZATION IN FLOWERING PLANTS 390

25 MECHANISMS OF TRANSPORT IN PLANTS 408

26 RESPONSE MECHANISMS IN PLANTS 420

X

PART IV ANIMAL EVOLUTION AND DIVERSITY 433 27 ANIMAL ORIGINS AND THE LOWER

INVERTEBRATES 434

28 THE COELOMATE INVERTEBRATES 452

29 THE VERTEBRATES 472

30 HUMAN EVOLUTION 492

PART V ANIMAL REGULATION 503 31 VERTEBRATE SUPPORT AND

MOVEMENT 504

32 NEURONS AND HOW THEY WORK 520

33 THE CENTRAL NERVOUS SYSTEM 534

34 THE SPECIAL SENSES 551—

35 CHEMICAL MESSENGERS IN ANIMALS 561

36 HOMEOSTASIS AND LIFE'S DELICATE BALANCE 575

PART VI ANIMAL MAINTENANCE AND REPRODUCTION 589 37 DIGESTION AND NUTRITION 590

38 GAS EXCHANGE 605

39 CIRCULATION 619

40 LMMUNITY 635

41 REPRODUCTION 649

42 DEVELOPMENT 664

PART VII BEHAVIOR AND ECOLOGY: Interrelationships in a Complex Biosphere 683

43 THE MECHANISMS AND DEVELOPMENT OF BEHAVIOR 684

44 THE ADAPTIVENESS OF BEHAVIOR 698

45 THE BIOSPHERE AND ITS ORGANIZATION 717

46 ECOSYSTEMS AND COMMUNITIES 740

47 POPULATIONS AND HOW THEY CHANGE 758

48 THE HUMAN POPULATION 770

APPENDIX A A GEOLOGICAL TIMETABLE A-l

APPENDIX B A CLASSIFICATION OF ORGANISMS A-2

Contents in Brief xi

CONTENTS

PARTI SCIENCE AND THE ONGOING FLOW OF LIFE I

1 SCIENCE AND ITS DESCENT 2 Galileo and the Roots of Science 2 Scientific Method 4

Inductive Reasoning 4 Deductive Reasoning 6 4 Hypothesis, Theory, and Law 6 Experiment 7

ESSAY 1.1 How Scientists Spread the News 8 The Workings of Science 10

Reductionists and Synthesists 10 Revolutions and Paradigms 10 Vitalism and Mechanism 10

The Unity and Diversity of Life 11 The Unity and Characteristics of Life 11 Biological Diversity and the Wider View

of Life 14 __ Summary 15 Key Terms 16 Review Questions 16

2 THE BASIC CHEMISTRY OF LIFE 17 The Elements 17 Atoms and Their Structure 17

Isotopes 18 Depicting the Atom -19

Molecules and Compounds 21 Interaction and Shifting Energy 22 Chemical Bonds 23

The Ionic Bond 23 The Covalent Bond: Sharing Electrons 24

Hydrogen Bonds and the Peculiar Qualities of Water 24

The Molecular Structure of Water 24 Water, Acids, Bases, and the pH Scale 27

Summary 29 Key Terms 29 Review Questions 30

3 THE MOLECULES OF LIFE 31 Carbon: Backbone of the Molecules of Life 31 Carbohydrates 32

Monosaccharides: Simple Sugars 32 Disaccharides: Linking the

Monosaccharides 33 Polysaccharides: The Larger Carbohydrates 34

Lipids 35 Triglycerides and Their Subunits 35 Phospholipids 37 Other Important Lipids 38

Proteins 39 Amino Acids 39 Protein Organization 41

Nucleic Acids: RNA and DNA 43 Summary 43 Key Terms 44 Review Questions 44

4 THE STRUCTURE AND FUNCTION OF CELLS 45 Cell Theory 46 ESSAY 4.1 Life Without Cells 47

What Is a Cell? 47 Cell Size 47

-A Look at Cell Diversity 50 Cell Structure 50

Support and Transport 50 Cell Control: The Nucleus 55

ESSAY 4.2 How Cytologists Sec Cells 56 Organelles of Cell Synthesis, Storage,

Digestion, and Sccrction 58 Cell Energy 60 Cell Movement 60

The Prokarvotic Cell: A Different Matter 65 Characteristics of the Prokarvotic Cell 65

Summary 66 Key Terms 67 Review Questions 67

xii

5 CELL TRANSPORT 68 Passive Transport 68

Diffusion 68 Water Potential and Bulk Flow 70 Osmosis: A Special Case 70

Active Transport 72 Membrane Pumps 73 Endocytosis and Exocytosis 73

Direct Transport Between Cells 75 Summary 76 Key Terms 76 Review Questions 77

6 ENERGY AND THE CELL 78 Energy 78

Potential and Kinetic Energy 79 The Laws of Thermodynamics 79

The First Law 79 The Second Law 80 Thermodynamics and the Delicate Processes

ofLife_ 81 Chemical Reactions and Energy States 81

Quieter Changes in Energy States 82 Enzymes: Biological Catalysts 82

A Matter of Shape 83 Characteristics of Enzyme Action 84

ATP: The Energy Currency of the Cell 86 Structure of ATP 86 ATP and Cellular Chemistry 87 The ATP Cycle 88

Coenzymes, Oxidation, and Reduction 89 Structure of NAD+, NADP+, and FAD Oxidation and Reduction by Coenzymes Reducing Power and Electron Transport

Systems 90 Formation of ATP in Cells 90

Chemiosmosis and Chemiosmotic Phosphorylation 90

Summary 93 Key Terms 94 Review Questions 95

89 90

7 PHOTOSYNTHESIS 96 Overview of Photosynthesis 96 The Chloroplast 97

Photosystems 97 Electron Transport Systems and Proton

Pumps 99 ESSAY 7.1 The Visible Light Spectrum and Photosynthesis 100 The Photosynthetic Process 102 The Light Reactions 102

Non-Cyclic Events 102 Cyclic Events 104 Chemiosmotic Phosphorylation 105

The Light-Independent Reactions 106 The Calvin Cycle 106

ESSAY 7.2 Problems with the Calvin Cycle— and the C4 Alternative 108

What Does a Plant Do with Its Glucose? 110 Have You Thanked a Plant Today? Ill Summary 111' Key Terms 112 Review Questions 112

8 GLYCOLYSIS AND RESPIRATION 114 Glycolysis 115 Cellular Respiration 115

Citric Acid Cycle 117 ESSAY 8.1 Alternative Fuels of the Cell 120

The Electron Transport Systems and Proton Pumping 121

Chemiosmotic Phosphorylation 122 Energy Efficiency in Glycolysis and Cell

Respiration 123 The Fermentation Alternative 123

Alcohol Fermentation and Yeast 123 Lactate Fermentation and Muscles 124

Summary 126 Key Terms 127 Review Questions 127

Contents xiii

9 MITOSIS AND CELL DIVISION 128 The Cell Cycle and DNA Replication 129

The Cell Cycle 129 DNA Replication: A Brief Look 130

A Closer Look at the Chromosome 131 Chromatin 131 Mitotic Chromosomes 131 Chromosome Numbers and Pairs 132

ESSAY 9.1 The Supercoiled Mitotic Chromosome 133 Mitosis 134

Mitosis in Animals 134 ESSAY 9.2 Karyotyping 135

Cytokinesis in Animals 138 Mitosis in Plants 139 Cytokinesis in Plants 139

Summing Up Cell Division 142 Summary 142 Key Terms - 143

• Review Questions 143 —

10 MEIOSIS AND SHUFFLING CHROMOSOMES 144 Meiosis: An Overview 144

Comparing Meiosis and Mitosis 145 Genetic Recombination 145

Meiosis I: The First Division 146 Prophase I 146 Metaphase I and Anaphase I 148 Telophase I 148

Meiosis II 148 Where Meiosis Takes Place 149

Meiosis in Humans 149 ESSAY 10.1 When Meiosis Goes Wrong 152

Meiosis in Plants 154 Summing Up 154

Summary 155 Key Terms 155 Review Questions 156

PART II GENETICS AND EVOLUTION: History and Horizons 157

11 GREGOR MENDEL AND THE FOUNDATIONS OF GENETICS 158 Mendel's Crosses 159 Mendel's First Law: Paired Factors and Their Segregation 159

The Experimental Procedure 160 Summing Up Mendel's First Law 162 Science and Models 163

ESSAY 11.1 Genes, Coins, and Probability 164 Mendel's Second Law: Independent Assortment 166

The 9:3:3:1 Ratio 167 The Test Cross 168 Summing Up Mendel's Second Law 168

The Decline and Rebirth of Mendelian Genetics 169 Summary 170 Key Terms 171 Review Questions 171

12 HOW GENES EXPRESS THEMSELVES 173 Normal and Abnormal Alleles 173 Going Beyond Mendel 174

Dominance Relationships: The Interactions Between Homologous Alleles 174

Multiple Alleles 176 ESSAY 12.1 Incompatible Rh Blood Types 177

Gene Interactions and Epistasis 178 Polygenic Inheritance 179 Other Sources of Variability 180

Summary 183 Key Terms 183 Review Questions 183

xiv Contents

13 GENES AND CHROMOSOMES 185 Mendel and Meiosis 185 Sex and the Chromosome Theory of Inheritance 187 Sex Linkage in Humans 187

The Y Chromosome 188 The X Chromosome and X-Linked

Genes 188 Barr Bodies, Drumsticks, and the Lyon

Effect 189 ESSAY 13.1 The Disease of Royalty 190 Gene Linkage 191

Problems with Mendel's Second Law 192 Genetic Recombination 193

Linkage Groups and Genetic Maps 193 Chromosomal Mutations and Abnormalities 195

Chromosomal Mutations 196 Summary 199 Key Terms 200 Review Questions 200

14 WHAT IS DNA? 201 Discovering DNA: The Stuff of Genes 201

Genes in Metabolic Pathways: An Early Look 202

Transformation 202 DNA: The Transforming Substance 202 One Gene, One Enzyme 203 Hershey and Chase: The Great Kitchen

Blender Experiment 204 Gene Structure: Closing in on DNA 205

ChargafPs Rule 206 Sizing Up the Molecule: X-Ray

Crystallography 206 DNA Structure: A Brief Look 207

The DNA Nucleotides 207 Watson, Crick, and the Great Synthesis 208

The Watson and Crick Model 208 Crick Solves the Riddle of DNA

Function 210 The Central Dogma 211

DNA Replication 211

Newer Developments in Molecular Biology 212 Cytoplasmic DNA 212 Repeated DNA Sequences and Satellite

DNA 213 Gene Amplification 214 Introns and Extrons 214 Transposons 214

Summary 215 Key Terms 216 Review Questions 216

15 DNA IN ACTION 218 The RNA Molecule 218 Transcription: The Synthesis of RNA 219 Three Kinds of RNA 219

Messenger RNA and the Genetic Code 220 Ribosomal RNA and the Ribosome 223 Transfer RNA 223

Protein Synthesis: Translation of the Genetic Message 225

Initiation 225 Elongation 225 Termination: Derailing the Ribosome 226 Polyribosomes 227

Mechanisms of Gene Control 229 Gene Organization and Control in

Prokaryotes: The Operon 229 Gene Control in Eukaryotes 231

Mutations: Errors in the Genetic Message 232 Chemical Stability and DNA Repair

Systems 233 Mutation at the Molecular Level 233

ESSAY 15.1 Linus Pauling and the Molecular Biology of Sickle Cell Anemia 236 Summary 238 Key Terms 239 Review Questions 239

Contents xv

16 FRONTIERS IN MOLECULAR BIOLOGY 241 Genetic Recombination in Bacteria 242

The Sex Life of E. coli 243 Plasmids and Plasmid Genes 246

Genetic Engineering 246 Recombinant DNA Technology: How Gene

Splicing, Cloning, and Sequencing Are Done 247

Gene Sequencing 249 DNA Libraries 251 Genetic Engineering: A Social Issue 253

ESSAY 16.1 Oncogenes and Heritable Cancers 254 Summary 255 Key Terms 256 Review Questions 256

17 PRINCIPLES OF EVOLUTION 257 Evolution Through Natural Selection 258

The Sources of Darwin's Ideas 259 Darwin the Experimenter 261 -

ESSAY 17.1 The Galapagos Islands 262 Evidence of Evolution 264

The Fossil Record 264 Biogeography 266 Comparative Anatomy: Homology and

Analog)' 266 Comparative Biochemistry and Genetic

Similarity 267 Summary 269 Key Terms 270 Review Questions 270

18 EVOLUTION IN POPULATIONS 271 The Population and How It Evolves 271

The Hardy-Weinberg Law and Populations in Equilibrium 272

An Algebraic Equivalent 274

Natural Selection 276 Lethal Alleles and Manx Cats 276 Natural Selection in a Changing Environment:

The Peppered Moth 277 Polygenic Inheritance and Natural

Selection 278 Patterns of Natural Selection 279

Mutation: The Raw Material of Evolution 281 Mutation Rates: The Constant Input of New

Information 281 Balance Between Mutation and Selection 282 Mutation and Natural Selection in

Humans 282 Genetic Drift 283

Neutralism: A Different View of Evolution 284

Summary 285 Key Terms 286 Review Questions 286

19 EVOLUTION AND THE ORIGIN OF SPECIES 288 Naming Names 288 What Is a Species? 289

Ranges, Clines, and Species 291 ESSAY 19.1 Products of Evolution: The Kingdoms 292 Mechanisms of Speciation 294

Reproductive Isolating Mechanisms 295 Allopatry and Speciation 295

ESSAY 19.2 Continents Adrift 296 Sympatry and Speciation 299

Major Evolutionary Trends 301 Divergent Evolution 302 Convergent Evolution 303 Coevolution 304 The Evolutionary Pace and Punctuated

Equilibrium 305 Evolution at the Molecular Level 305

The Molecular Clock 306 Summary 308 Key Terms 309 Review Questions 309

xvi Contents

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If 0

PART III FROM PROKARYOTES TO PLANTS 311

20 BACTERIA, VIRUSES, AND THE ORIGIN OF LIFE 312 The Origin of Life 312

The Miller-Urey Experiment 314 The Hypothesis Today 315 The Earliest Cells 3 i6

Kingdom Monera: The Prokaryotes 317 Bacterial Characteristics 317 Bacterial Cell 319 Heterotrophic Activities 320 Pathogenic Heterotrophs: The Villains 322 Autotrophic Activities 322 Prokaryote Origins and Phytogeny 324 Archaebacteria 324

Viruses 325 Viral Genome 325 How Viruses Behave—or Misbehave 325

Summary 329-Kev Terms 330 Review Questions 330

21 PROTISTS AND FUNGI: THE SIMPLER EUKARYOTES 332 What Is a Protist? 332. Protozoans: Animal-Like Protists 333

Flagellates and Amebas (Phylum Sarcomastigophora) 333

ESSAY 21.1 The Symbiosis Hypothesis 334 ESSAY 21.2 Diversity in Life Cycles and Alternation of Generations 336

Sporozoans (Phylum Apicomplexa) 338 Ciliates (Phylum Ciliophora) 339

Algae: Plandikie Protists 341 Dinoflagellates (Phylum Pyrrophyta) 341 Diatoms and Golden-Brown Algae (Phylum

Chrysophyta) 342 Euglenoids (Phylum Euglenophyta) 343 Red Algae (Phylum Rhodophyta) 343

Brown Algae (Phylum Phaeophvta) 344 Green Algae (Phylum Chlorophvta) 345

Slime Molds and Water Molds: Fungus-Like Protists 347

Slime Molds 347 Water Molds (Phylum Oomycota) 347

Fungi 347 Other Fungal Characteristics 348 Bread Molds (Phylum Zygomycota) 349 Sac Fungi (Phylum Ascomycota) 350 Club Fungi (Phylum Basidiomycota) 351 Fungi Imperfecti (Phylum

Deuteromycota) 353 Lichens 353 Summary 354 Key Terms 355 Review Questions 356

22 EVOLUTION AND DIVERSITY IN PLANTS 358 What Is a Plant? 358

Alternation of Generations in Plants 359 Nonvascular Plants: Bryophytes 359

Bryophyte Characteristics 359 Bryophyte Origins 360

Vascular Plants 360 Vascular Plant Divisions 361 Ferns 362

The Mesozoic Era: Time of Gymnosperms 365 Gvmnosperm Specializations 365 The Gymnosperms Today 366

The Cenozoic Era: The Time of the Flowering Plants 368

The Angiosperms Today 369 Summary 371 Key Terms 372 Review Questions 372

Contents xvii

23 REPRODUCTION IN THE FLOWERING PLANTS 373 Anatomy of the Flower 374 The Sex Life of the Flowering Plant 375

Inside the Ovary: Ovule and Embryo Sac 375

Inside the Anthers: Pollen Formation 375 Pollination and Fertilization 377

Embryo and Seed Development in a Dicot 378 The Mature Embryo 379 Seed Coats and Dormancy 380 Fruit 380 Seed Dispersal 380 Germination and Early Seedling

Development 380 The Seedling 381

ESSAY 23.1 Flowers to Fruits, or a Quince is a Pome 382 Summary 387 Key Terms 388 Review Questions- 388_

24 GROWTH AND ORGANIZATION IN FLOWERING PLANTS 390 Open or Indeterminate Growth 390 Primary and Secondary Growth 391 ESSAY 24.1 Totipotencv in Plant Cells 392 Tissue Organization 392

Vascular Tissues 393 The Root System 396

The Primary Root 396 Lateral Roots and Root Systems 399

The Shoot System 400 The Primary Shoot 400 Secondarv Growth in the Shoot 401

The Leaf 403 Leaf Anatomy 403

Summary 405 Key Terms 406 Review Questions 407

25 MECHANISMS OF TRANSPORT IN PLANTS 408 The Movement of Water and Minerals 408

Water Potential Revisited 408 The Transpiration-Adhesion-Cohesion-Tension

Hypothesis 409 Water Movement in the Root 412 Turgor and the Behavior of Stomata 413 Mineral Uptake by Roots 415 Mutualism and Mineral Uptake 415

Food Transport in the Phloem 416 Flow From Source to Sink 417 The Pressure Flow Hypothesis 417

Summary 418 Key Terms 419 Review Questions 419

26 RESPONSE MECHANISMS IN PLANTS 420 Plant Hormones and Their Actions 420

Auxin 420 Gibbcrellins 422 Cytokinins 423 Ethylene 423 Abscisic Acid 423

Artificial Auxins and Plant Control 425 Plant Tropisms 425

Phototropism 425 Gravitropism 426 Touch Response 427

Photoperiodism and Flowering Plants 427 Photoperiodism and the Length of

Night 428 Phytochrome: The Light Receptor 429

Summary 430 Key Terms 431 Review Questions 431

xviii Contents

PART IV ANIMAL EVOLUTION AND DIVERSITY 433

27 ANIMAL ORIGINS AND THE LOWER INVERTEBRATES 434 Body Organization 435 Phylogeny of the Animal Kingdom 435

The Early Fossil Record 437 Sponges: Porifera 438 Polyps and Medusas: Coelenterata 440

Polyp and Medusa Body Patterns 441 The Comb Jellies: Ctenophora 442 Cleavage Patterns and the Versatile Mesoderm 443

Protostomes and Deuterostomes 443 Flanvorms: Platyhelminthes 444

Parasitic Flanvorms 444 Body Cavities, a One-Way Gut, and a New Body Plan 446 Nematodes and Rotifers 448

Pseudocoeloms and the Roundworms 448 Summary 449 Key Terms 450 Review Questions 451

28 THE COELOMATE INVERTEBRATES 452 The Coelomate Body Plan 452

The Segmented Body 454 Shells and a Muscular Foot: The Mollusks (Phylum Mollusca) 454

Modern Mollusks 454 Segmented Worms: The Annelids (Phylum Annelida) 456

Earthworm 456 A Remarkable Success Story: The Arthropods (Phylum Arthropoda) 458

The Arthropods Today 458 Arthropod Diversity 458

The Deuterostomes: The Echinoderm-Chordate Line 464

Spiny Skins and Radial Bodies: The Echinoderms 464

Hemichordates 466 Chordates 466

Summary 469 Key Terms 470 Review Questions 470

29 THE VERTEBRATES 472 Humble Beginnings and the Jawlcss Fishes: Class Agatha 472 The First Jaws: Class Placodermi 473 Cartilaginous Fishes: Class Chondrichthyes 474

The Shark 474 The Bony Fishes: Class Osteichthyes 475

Bony Fishes 477 Vertebrates Invade the Land 478

Lobe-Finned Fishes: A Dead End and a New Opportunity 478

The Transitional Amphibians 479 Modern Amphibians 480

Reptiles and the Transition to Land 481 The Age of Reptiles 482 Exit the Great Reptiles 483 Modern Reptiles 483

Birds Take to the Air 483 ESSAY 29.1 Asteroids and the Great Extinctions 484 Another Success Story: Mammals 487

The Age of Mammals 487 Modern Mammals 489

Summary 489 Key Terms 490 Review Questions 491

Contents xix

30 HUMAN EVOLUTION 492 Primate Origins 492

Modern Primates 493 The Human Line 496

The Australopithecines 496 Homo habilis 499 Homo erectus 499 Neanderthals and Us 500

Summary 501 Key Terms 502 Review Questions 502

PART V ANIMAL REGULATION 503

31 VERTEBRATE SUPPORT AND MOVEMENT 504 Vertebrate Tissues 504

Epithelial Tissue 504 Connective Tissue 505 Muscle Tissue 505" — Nerve Tissue 506

The Vertebrate Skeleton 507 Structure of Bone 507 Organization of the Human Skeleton 507

Vertebrate Muscle and Its Movement 511 Muscle Tissue Types 511 Organization of Skeletal Muscle 512 Ultrastructure of Skeletal Muscle 512 Contraction of Skeletal Muscle 515

Summary 517 Key Terms 518 Review Questions 519

32 NEURONS AND HOW THEY WORK 520 The Neuron 520

Types of Neurons 522 Nerves 522

The Neural Impulse 522 The Resting State: A Matter of Ion

Distribution 523 The Action Potential 524 Ion Channels and Ion Gates 526 Myelin and Impulse Velocity 526

Communication Among Neurons 528 Action at the Synapse 529

The Reflex Arc 530 Summary 531 Key Terms 532 Review Questions 532

33 THE CENTRAL NERVOUS SYSTEM 534 Evolution of the Central Nervous System 534 The Human Brain 536 The Hindbrain 536 The Midbrain 537 The Forebrain 537

The Thalamus 538 The Reticular System 538 The Hypothalamus 538 The Cerebrum 538

The Spinal Cord 542 Chemicals in the Brain 543 Electrical Activity in the Brain 543

Sleep 543 ESSAY 33.1 Alzheimer's Disease 544 Memory 545 The Peripheral Nervous System 546

The Autonomic Nervous System 546 Summary 548 Key Terms 549 Review Questions 550

xx Contents

34 THE SPECIAL SENSES 551 Mechanoreceptors: Touch and Pressure 552 Thermoreceptors 552 Chemoreceptors: Taste and Smell 553 Auditor)' Receptors 553

Auditory Receptors in Humans 555 ' Gravity and Movement Receptors 556 Visual Receptors 556

The Retina 557 Summary 559 Key Terms 560 Review Questions 560

35 CHEMICAL MESSENGERS IN ANIMALS 561 Nature of Hormones 561

Hormones and Feedback Mechanisms . 562 Human Endocrine System 564

The Pituitary 564 The Thyroid Gland 567 The Parathyroid Glands and Calcium

Regulation 567 The Pancreas and the Islets of

Langerhans 568 The Adrenal Glands 569 Ovaries and Testes 570 Other Chemical Messengers 570

How Hormones Work 571 Cellular Biology of Hormone Action 571 Hormones as Gene Activators 572

Summary 573 Key Terms 574 Review Questions 574

36 HOMEOSTASIS AND LIFE'S DELICATE BALANCE 575 The Nature of Homeostatic Mechanisms 575 Thermoregulation 576

Why Thermoregulate? 576 Homeotherms and Poikilotherms 577 Thermoregulation in Humans 577

ESSAY 36.1 A Warm-Bodied Fish 578 Osmoregulation and Excretion 580

The Human Excretory System 581 Hormonal Control in the Nephron 585

Summary 587 Key Terms 588 Review Questions 588

PART VI ANIMAL MAINTENANCE AND REPRODUCTION 589

37 DIGESTION AND NUTRITION 590 Digestion in Invertebrates 590 Vertebrate Specializations 592 The Human Digestive System 594

The Mouth and Esophagus 594 The Stomach 595 The Small Intestine 595 The Liver 596 The Pancreas 598 The Colon 598 Chemical Digestion and Absorption 598 Integration and Control of the Digestive

Process 600 Some Essentials of Nutrition 600

Carbohydrates 600 Fats 601 Protein 601 Vitamins 601 Mineral Requirements 602 Moderation Is Its Own Reward 602

Summary 602 Key Terms 604 Review Questions 604

Contents xxi

38 GAS EXCHANGE 605 40 IMMUNITY 635 Gas Exchange: An Evolutionary Perspective 605 The Respirator)' Interface 606

Variations in the Interface 607 The Human Respirator)' System 609

The Larynx 609 The Trachea and Bronchial Tree 609 The Alveolar Interface 611 The Lungs and Breathing 611 The Exchange of Gases 612 Respirator)' Control 614

Summary 616 Key Terms 617 Review Questions 618

39 CIRCULATION 619 Animal Circulator)' Systems 619

Invertebrates 619 Vertebrates 620

The Human Circulatory System 620 The Heart 620 —— Structures of the Heart 622

. Control of the Heart 623 Blood Vessels and Circulator)' Routes 625

ESSAY 39.1 When the Heart Fails 627 Blood 629

Components of Blood 629 The Lymphatic System 631 Summary 632 Key Terms 633 Review Questions 633

Chemical Defenses: The Front Line 635 Cellular Responses: Roving Defenders 636

The Macrophage as an Antigen-Presenting Cell 637

Introducing the B-Cell and T-Cell Lymphocytes 638

Arousing the Lymphocytes: The Primary Immune Response 639

Aroused B-Cell Lymphocytes 639 Aroused T-Cell Lymphocytes 639

_ Memory Cells and the Secondary Immune Response 641

ESSAY 40.1 Recognizing "Self' 642 Immunoglobin Structure 642

The Source of Cell Surface and Immunoglobin Diversity 644

Monoclonal Antibodies 644 AIDS and the Crippled Immune System 645

The Growing AIDS Epidemic 645 The Agent of AIDS 646

Summary 647 Key Terms 648 Review Questions 648

41 REPRODUCTION 649 Reproduction in Representative Animals 649

Asexual vs Sexual Reproduction 649 Modes of Sexual Reproduction 650

Human Reproduction 651 Males 651

xxii Contents

ESSAY 41.1 The Sexual Response 652 Females 654

Hormones and Human Reproduction 656 Hormonal Control in Males 657 Hormonal Control in Females 657 Ovarian and Menstrual Cycles 657

Birth Control 660 The Rhythm Method 660 Birth Control Pills 660

Summary 662 Key Terms 663 Review Questions 663

42 DEVELOPMENT 664 Gametes and Fertilization 664

Sperm 664 Eggs 665 Fertilization 665

Early Developmental Events 666 Cleavage 666 Morula and Blastula 668 Gastrula 668 Neurulation and the Body Axis 670

Tissue Interaction and Embryonic Induction 670 Human Development 673

Early Events 673 Implantation and-Early Life Support 674 Early Development and Formation of the

Placenta 674 Further Human Development 676

Birth 677 Physiological Changes in the Newborn 678

Summary 679 Key Terms 680 Review Questions 680

PART VII BEHAVIOR AND ECOLOGY: Interrelationships in a Complex Biosphere 683

43 THE MECHANISMS AND DEVELOPMENT OF BEHAVIOR 684 Instinct 684

Fixed-Action Patterns 685 Orienting the Fixed-Action Patterns 686 Thresholds and Releasers 687 Perspectives on Instinct 688

Learning 689 Reward 689 Kinds of Learning 689

ESSAY 43.1 Play 690 Habituation 691

ESSAY 43.2 On Imprinting 692 Classical Conditioning 693 Operant Conditioning 694

Summary 696 Key Terms 696 Review Questions 697

44 THE ADAPTTVENESS OF BEHAVIOR 698 Arranging Oneself in Space 698

Kinesis and Taxis 699 Orientation and Navigation 699

ESSAY 44.1 Biological Clocks 700 Communication 703

Deception 703 Visual Communication 703

ESSAY 44.2 Deception in the Animal World 704

Sound Communication 706 Chemical Communication 707

Contents xxiii

ESSAY 44.3 Coevolution of Hearing in Bats and Moths 708

Why Communicate? 710 Aggression 710

Fighting 710 Territories 711

Cooperation 711 Altruism 712 Sociobiology 714 Summary 714 Key Terms 715 Review Questions 716

45 THE BIOSPHERE AND ITS ORGANIZATION 717 The Biosphere 717

The Atmosphere 717 Solar Energy 718 Climate and the Tilted Earth 718

. ESSAY 45.1 Carbon-Dioxide^and the Greenhouse Effect: A Destabilized-

Equilibrium 719 Biomes and Waters of the Earth 720 The Tropical Rain Forest Biome 721

Plant and Animal Associations 722 The Tropical Savanna Biome 723

Plant and Animal Associations 723 The Desert Biome 724

Plant and Animal Assqciations 724 The Chaparral Biome 725 The Grassland Biome 726

Plant and Animal Associations 727 The Temperate Deciduous Forest Biome 727

Plant and Animal Associations 728 The Taiga Biome 728

Plant and Animal Associations 729 The Tundra Biome 730

Plant and Animal Associations 730

The Marine Environment 730 The Oceanic Province 731 The Neritic Province 732 Coastal Communities 732

The Freshwater Environment 734 Life in the Lake Zones 734 Thermal Overturn and Lake Productivity

Summary 737 Key Terms 739 Review Questions 739

46 ECOSYSTEMS AND COMMUNITIES 740 Energetics in Ecosystems 740

Trophic Levels 740 ESSAY 46.1 The Oceanic Rift: An Unusual Community 742

Ecological Pyramids 744 Productivity in Ecosystems 746

Nutrient Cycling in Ecosystems 748 The Nitrogen Cycle 750

Communities Over Time: Ecological Succession 752

Primary Succession 752 Secondary Succession 753

. Succession in the Freshwater Aquatic Community 754

Eutrophication: Human Impact 755 Summary 755 Key Terms 756 Review Questions 756

xxiv Contents

47 POPULATIONS AND HOW THEY CHANGE 758 Population Growth Patterns 758

Life Span and the Population 760 Adaptive Strategies of Populations 760

Influences on Population Density 761 Density-Independent and Density-Dependent

Controls 761 More About Biotic Controls 762

ESSAY 47.1 Holes in the Sky 765 ESSAY 47.2 What Have They Done to the Rain? 766 Summary 768 Key Terms 768 Review Questions 769

48 THE HUMAN POPULATION 770 Human Population History 770

The First Population Surge 771 The Second Population Surge 771 The Third Population Surge 773

The Human Population Today ~774 Growth in the Developing Regions 774 Demographic Transition 775

The Future of the Human Population 776 Changing Attitudes 776 Population Structure. 776 Growth Predictions and the Earth's Carrying

Capacity 776 Summary 778 Key Terms 778 Review Questions 779

Appendix A GEOLOGIC TIMETABLE A-1

Appendix B CLASSIFICATION OF ORGANISMS A-2

Suggested Readings R-l" Glossary G-l

Illustration Acknowledgments C-l Index 1-1

Contents xxv