Biology

Concepts of Biology

SENIOR CONTRIBUTING AUTHORS SAMANTHA FOWLER, CLAYTON STATE UNIVERSITY REBECCA ROUSH, SANDHILLS COMMUNITY COLLEGE JAMES WISE, HAMPTON UNIVERSITY

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Table of Contents Preface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 Unit 1. The Cellular Foundation of Life

Chapter 1: Introduction to Biology . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 1.1 Themes and Concepts of Biology . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 1.2 The Process of Science . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16

Chapter 2: Chemistry of Life . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27 2.1 The Building Blocks of Molecules . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28 2.2 Water . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34 2.3 Biological Molecules . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39

Chapter 3: Cell Structure and Function . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55 3.1 How Cells Are Studied . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55 3.2 Comparing Prokaryotic and Eukaryotic Cells . . . . . . . . . . . . . . . . . . . . . . . 59 3.3 Eukaryotic Cells . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 61 3.4 The Cell Membrane . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 74 3.5 Passive Transport . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 77 3.6 Active Transport . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 81

Chapter 4: How Cells Obtain Energy . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 91 4.1 Energy and Metabolism . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 92 4.2 Glycolysis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 102 4.3 Citric Acid Cycle and Oxidative Phosphorylation . . . . . . . . . . . . . . . . . . . . . 104 4.4 Fermentation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 107 4.5 Connections to Other Metabolic Pathways . . . . . . . . . . . . . . . . . . . . . . . . 111

Chapter 5: Photosynthesis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 117 5.1 Overview of Photosynthesis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 117 5.2 The Light-Dependent Reactions of Photosynthesis . . . . . . . . . . . . . . . . . . . . 122 5.3 The Calvin Cycle . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 126

Unit 2. Cell Division and Genetics Chapter 6: Reproduction at the Cellular Level . . . . . . . . . . . . . . . . . . . . . . . . . . 135

6.1 The Genome . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 135 6.2 The Cell Cycle . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 137 6.3 Cancer and the Cell Cycle . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 143 6.4 Prokaryotic Cell Division . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 145

Chapter 7: The Cellular Basis of Inheritance . . . . . . . . . . . . . . . . . . . . . . . . . . . 153 7.1 Sexual Reproduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 153 7.2 Meiosis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 157 7.3 Errors in Meiosis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 163

Chapter 8: Patterns of Inheritance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 173 8.1 Mendel’s Experiments . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 174 8.2 Laws of Inheritance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 178 8.3 Extensions of the Laws of Inheritance . . . . . . . . . . . . . . . . . . . . . . . . . . 185

Unit 3. Molecular Biology and Biotechnology Chapter 9: Molecular Biology . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 199

9.1 The Structure of DNA . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 200 9.2 DNA Replication . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 204 9.3 Transcription . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 210 9.4 Translation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 213 9.5 How Genes Are Regulated . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 216

Chapter 10: Biotechnology . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 225 10.1 Cloning and Genetic Engineering . . . . . . . . . . . . . . . . . . . . . . . . . . . . 225 10.2 Biotechnology in Medicine and Agriculture . . . . . . . . . . . . . . . . . . . . . . . 232 10.3 Genomics and Proteomics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 236

Unit 4. Evolution and the Diversity of Life Chapter 11: Evolution and Its Processes . . . . . . . . . . . . . . . . . . . . . . . . . . . . 249

11.1 Discovering How Populations Change . . . . . . . . . . . . . . . . . . . . . . . . . . 250 11.2 Mechanisms of Evolution . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 255 11.3 Evidence of Evolution . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 258 11.4 Speciation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 261

11.5 Common Misconceptions about Evolution . . . . . . . . . . . . . . . . . . . . . . . . 266 Chapter 12: Diversity of Life . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 275

12.1 Organizing Life on Earth . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 275 12.2 Determining Evolutionary Relationships . . . . . . . . . . . . . . . . . . . . . . . . . 280

Chapter 13: Diversity of Microbes, Fungi, and Protists . . . . . . . . . . . . . . . . . . . . . 291 13.1 Prokaryotic Diversity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 292 13.2 Eukaryotic Origins . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 302 13.3 Protists . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 304 13.4 Fungi . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 311

Chapter 14: Diversity of Plants . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 325 14.1 The Plant Kingdom . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 326 14.2 Seedless Plants . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 332 14.3 Seed Plants: Gymnosperms . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 338 14.4 Seed Plants: Angiosperms . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 343

Chapter 15: Diversity of Animals . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 355 15.1 Features of the Animal Kingdom . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 356 15.2 Sponges and Cnidarians . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 361 15.3 Flatworms, Nematodes, and Arthropods . . . . . . . . . . . . . . . . . . . . . . . . . 367 15.4 Mollusks and Annelids . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 374 15.5 Echinoderms and Chordates . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 380 15.6 Vertebrates . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 385

Unit 5. Animal Structure and Function Chapter 16: The Body’s Systems . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 403

16.1 Homeostasis and Osmoregulation . . . . . . . . . . . . . . . . . . . . . . . . . . . . 404 16.2 Digestive System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 408 16.3 Circulatory and Respiratory Systems . . . . . . . . . . . . . . . . . . . . . . . . . . 414 16.4 Endocrine System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 420 16.5 Musculoskeletal System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 426 16.6 Nervous System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 431

Chapter 17: The Immune System and Disease . . . . . . . . . . . . . . . . . . . . . . . . . 449 17.1 Viruses . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 450 17.2 Innate Immunity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 456 17.3 Adaptive Immunity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 459 17.4 Disruptions in the Immune System . . . . . . . . . . . . . . . . . . . . . . . . . . . 468

Chapter 18: Animal Reproduction and Development . . . . . . . . . . . . . . . . . . . . . . 477 18.1 How Animals Reproduce . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 478 18.2 Development and Organogenesis . . . . . . . . . . . . . . . . . . . . . . . . . . . . 482 18.3 Human Reproduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 484

Unit 6. Ecology Chapter 19: Population and Community Ecology . . . . . . . . . . . . . . . . . . . . . . . . 499

19.1 Population Demographics and Dynamics . . . . . . . . . . . . . . . . . . . . . . . . 500 19.2 Population Growth and Regulation . . . . . . . . . . . . . . . . . . . . . . . . . . . 504 19.3 The Human Population . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 510 19.4 Community Ecology . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 514

Chapter 20: Ecosystems and the Biosphere . . . . . . . . . . . . . . . . . . . . . . . . . . . 529 20.1 Energy Flow through Ecosystems . . . . . . . . . . . . . . . . . . . . . . . . . . . . 530 20.2 Biogeochemical Cycles . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 537 20.3 Terrestrial Biomes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 547 20.4 Aquatic and Marine Biomes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 554

Chapter 21: Conservation and Biodiversity . . . . . . . . . . . . . . . . . . . . . . . . . . . 567 21.1 Importance of Biodiversity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 568 21.2 Threats to Biodiversity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 575 21.3 Preserving Biodiversity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 582

Appendix A: The Periodic Table of Elements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 593 Appendix B: Geological Time . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 595 Appendix C: Measurements and the Metric System . . . . . . . . . . . . . . . . . . . . . . . . . 597 Index . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 605

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PREFACE Welcome to Concepts of Biology, an OpenStax resource. This textbook has been created with several goals in mind: accessibility, customization, and student engagement—all while encouraging students toward high levels of academic scholarship. Instructors and students alike will find that this textbook offers a strong introduction to biology in an accessible format.

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