Principles of Life
The Authors
Brief Table of Contents
Preface
Advisors and Reviewers
Launchpad for Principles of Life, SECOND EDITION
Table of Contents
Principles of Life
Concept 1.1: Living Organisms Share Common Aspects of Structure, Function, and Energy Flow
Concept 1.2: Life Depends on Organization and Energy
Concept 1.3: Genetic Systems Control the Flow, Exchange, Storage, and Use of Information
Concept 1.4: Evolution Explains the Diversity as Well as the Unity of Life
Concept 1.5: Science Is Based on Quantitative Observations, Experiments, and Reasoning
Cells
The Chemistry and Energy of Life
Concept 2.1: Atomic Structure Is the Basis for Life’s Chemistry
Concept 2.2: Atoms Interact and Form Molecules
Concept 2.3: Carbohydrates Consist of Sugar Molecules
Concept 2.4: Lipids Are Hydrophobic Molecules
Concept 2.5: Biochemical Changes Involve Energy
Summary
Nucleic Acids, Proteins, and Enzymes
Concept 3.1: Nucleic Acids Are Informational Macromolecules
Concept 3.2: Proteins Are Polymers with Important Structural and Metabolic Roles
Concept 3.3: Some Proteins Act as Enzymes to Speed up Biochemical Reactions
Concept 3.4: Regulation of Metabolism Occurs by Regulation of Enzymes
Summary
Cells: The Working Units of Life
Concept 4.1: Cells Provide Compartments for Biochemical Reactions
Concept 4.2: Prokaryotic Cells Do Not Have a Nucleus
Concept 4.3: Eukaryotic Cells Have a Nucleus and Other Membrane-Bound Compartments
Concept 4.4: The Cytoskeleton Provides Strength and Movement
Concept 4.5: Extracellular Structures Provide Support and Protection For Cells and Tissues
Summary
Cell Membranes and Signaling
Concept 5.1: Biological Membranes Have a Common Structure and Are Fluid
Concept 5.2: Passive Transport across Membranes Requires No Input of Energy
Concept 5.3: Active Transport Moves Solutes against Their Concentration Gradients
Concept 5.4: Large Molecules Cross Membranes via Vesicles
Concept 5.5: The Membrane Plays a Key Role in a Cell’s Response to Environmental Signals
Concept 5.6: Signal Transduction Allows the Cell to Respond to Its Environment
Summary
Pathways that Harvest and Store Chemical Energy
Concept 6.1: ATP and Reduced Coenzymes Play Important Roles in Biological Energy Metabolism
Concept 6.2: Carbohydrate Catabolism in the Presence of Oxygen Releases a Large Amount of Energy
Concept 6.3: Carbohydrate Catabolism in the Absence of Oxygen Releases a Small Amount of Energy
Concept 6.4: Catabolic and Anabolic Pathways Are Integrated
Concept 6.5: During Photosynthesis, Light Energy Is Converted to Chemical Energy
Concept 6.6: Photosynthetic Organisms Use Chemical Energy to Convert CO2 to Carbohydrates
Summary
Genetics
The Cell Cycle and Cell Division
Concept 7.1: Different Life Cycles Use Different Modes of Cell Reproduction
Concept 7.2: Both Binary Fission and Mitosis Produce Genetically Identical Cells
Concept 7.3: Cell Reproduction Is Under Precise Control
Concept 7.4: Meiosis Halves the Nuclear Chromosome Content and Generates Diversity
Concept 7.5: Programmed Cell Death Is a Necessary Process in Living Organisms
Summary
Inheritance, Genes, and Chromosomes
Concept 8.1: Genes Are Particulate and Are Inherited According to Mendel’s Laws
Concept 8.2: Alleles and Genes Interact to Produce Phenotypes
Concept 8.3: Genes Are Carried on Chromosomes
Concept 8.4: Prokaryotes Can Exchange Genetic Material
Summary
DNA and Its Role in Heredity
Concept 9.1: DNA Structure Reflects Its Role as the Genetic Material
Concept 9.2: DNA Replicates Semiconservatively
Concept 9.3: Mutations Are Heritable Changes in DNA
Summary
From DNA to Protein: Gene Expression
Concept 10.1: Genetics Shows That Genes Code for Proteins
Concept 10.2: DNA Expression Begins with Its Transcription to RNA
Concept 10.3: The Genetic Code in RNA Is Translated into the Amino Acid Sequences of Proteins
Concept 10.4: Translation of the Genetic Code Is Mediated by tRNAs and Ribosomes
Concept 10.5: Proteins Are Modified after Translation
Summary
Regulation of Gene Expression
Concept 11.1: Many Prokaryotic Genes Are Regulated in Operons
Concept 11.2: Eukaryotic Genes Are Regulated by Transcription Factors
Concept 11.3: Gene Expression Can Be Regulated via Epigenetic Changes to Chromatin
Concept 11.4: Eukaryotic Gene Expression Can Be Regulated after Transcription
Summary
Genomes
Concept 12.1: There Are Powerful Methods for Sequencing Genomes and Analyzing Gene Products
Concept 12.2: Prokaryotic Genomes Are Small, Compact, and Diverse
Concept 12.3: Eukaryotic Genomes Are Large and Complex
Concept 12.4: The Human Genome Sequence Has Many Applications
Summary
Biotechnology
Concept 13.1: Recombinant DNA Can Be Made in the Laboratory
Concept 13.2: DNA Can Genetically Transform Cells and Organisms
Concept 13.3: Genes Come from Various Sources and Can Be Manipulated
Concept 13.4: Biotechnology Has Wide Applications
Summary
Genes, Development, and Evolution
Concept 14.1: Development Involves Distinct but Overlapping Processes
Concept 14.2: Changes in Gene Expression Underlie Cell Fate Determination and Differentiation
Concept 14.3: Spatial Differences in Gene Expression Lead to Morphogenesis
Concept 14.4: Changes in Gene Expression Pathways Underlie the Evolution of Development
Concept 14.5: Developmental Genes Contribute to Species Evolution but Also Pose Constraints
Summary
Evolution
Processes of Evolution
Concept 15.1: Evolution Is Both Factual and the Basis of Broader Theory
Concept 15.2: Mutation, Selection, Gene Flow, Genetic Drift, and Nonrandom Mating Result in Evolution
Concept 15.3: Evolution Can Be Measured by Changes in Allele Frequencies
Concept 15.4: Selection Can Be Stabilizing, Directional, or Disruptive
Concept 15.5: Genomes Reveal Both Neutral and Selective Processes of Evolution
Concept 15.6: Recombination, Lateral Gene Transfer, and Gene Duplication Can Result in New Features
Concept 15.7: Evolutionary Theory Has Practical Applications
Summary
Reconstructing and Using Phylogenies
Concept 16.1: All of Life Is Connected through Its Evolutionary History
Concept 16.2: Phylogeny Can Be Reconstructed from Traits of Organisms
Concept 16.3: Phylogeny Makes Biology Comparative and Predictive
Concept 16.4: Phylogeny Is the Basis of Biological Classification
Summary
Speciation
Concept 17.1: Species Are Reproductively Isolated Lineages on the Tree of Life
Concept 17.2: Speciation Is a Natural Consequence of Population Subdivision
Concept 17.3: Speciation May Occur through Geographic Isolation or in Sympatry
Concept 17.4: Reproductive Isolation Is Reinforced When Diverging Species Come into Contact
Summary
The History of Life on Earth
Concept 18.1: Events in Earth’s History Can Be Dated
Concept 18.2: Changes in Earth’s Physical Environment Have Affected the Evolution of Life
Concept 18.3: Major Events in the Evolution of Life Can Be Read in the Fossil Record
Summary
Diversity
Bacteria, Archaea, and Viruses
Concept 19.1: Life Consists of Three Domains That Share a Common Ancestor
Concept 19.2: Prokaryote Diversity Reflects the Ancient Origins of Life
Concept 19.3: Ecological Communities Depend on Prokaryotes
Concept 19.4: Viruses Have Evolved Many Times
Summary
The Origin and Diversification of Eukaryotes
Concept 20.1: Eukaryotes Acquired Features from Both Archaea and Bacteria
Concept 20.2: Major Lineages of Eukaryotes Diversified in the Precambrian
Concept 20.3: Protists Reproduce Sexually and Asexually
Concept 20.4: Protists Are Critical Components of Many Ecosystems
Summary
The Evolution of Plants
Concept 21.1: Primary Endosymbiosis Produced the First Photosynthetic Eukaryotes
Concept 21.2: Key Adaptations Permitted Plants to Colonize Land
Concept 21.3: Vascular Tissues Led to Rapid Diversification of Land Plants
Concept 21.4: Seeds Protect Plant Embryos
Concept 21.5: Flowers and Fruits Increase the Reproductive Success of Angiosperms
Summary
The Evolution and Diversity of Fungi
Concept 22.1: Fungi Live by Absorptive Heterotrophy
Concept 22.2: Fungi Can Be Saprobic, Parasitic, Predatory, or Mutualistic
Concept 22.3: Major Groups of Fungi Differ in Their Life Cycles
Concept 22.4: Fungi Can Be Sensitive Indicators of Environmental Change
Summary
Animal Origins and Diversity
Concept 23.1: Distinct Body Plans Evolved among the Animals
Concept 23.2: Some Animal Groups Fall outside the Bilateria
Concept 23.3: Protostomes Have an Anterior Brain and a Ventral Nervous System
Concept 23.4: Arthropods Are Diverse and Abundant Animals
Concept 23.5: Deuterostomes Include Echinoderms, Hemichordates, and Chordates
Concept 23.6: Life on Land Contributed to Vertebrate Diversification
Concept 23.7: Humans Evolved among the Primates
Summary
Plant Form and Function
The Plant Body
Concept 24.1: The Plant Body Is Organized and Constructed in a Distinctive Way
Concept 24.2: Apical Meristems Build the Primary Plant Body
Concept 24.3: Many Eudicot Stems and Roots Undergo Secondary Growth
Concept 24.4: Domestication Has Altered Plant Form
Summary
Plant Nutrition and Transport
Concept 25.1: Plants Acquire Mineral Nutrients from the Soil
Concept 25.2: Soil Organisms Contribute to Plant Nutrition
Concept 25.3: Water and Solutes Are Transported in the Xylem by Transpiration–Cohesion–Tension
Concept 25.4: Solutes Are Transported in the Phloem by Pressure Flow
Summary
Plant Growth and Development
Concept 26.1: Plants Develop in Response to the Environment
Concept 26.2: Gibberellins and Auxin Have Diverse Effects but a Similar Mechanism of Action
Concept 26.3: Other Plant Hormones Have Diverse Effects on Plant Development
Concept 26.4: Photoreceptors Initiate Developmental Responses to Light
Summary
Reproduction of Flowering Plants
Concept 27.1: Most Angiosperms Reproduce Sexually
Concept 27.2: Hormones and Signaling Determine the Transition from the Vegetative to the Reproductive State
Concept 27.3: Angiosperms Can Reproduce Asexually
Summary
Plants in the Environment
Concept 28.1: Plants Have Constitutive and Induced Responses to Pathogens
Concept 28.2: Plants Have Mechanical and Chemical Defenses against Herbivores
Concept 28.3: Plants Adapt to Environmental Stresses
Summary
Animal Form and Function
Fundamentals of Animal Function
Concept 29.1: Animals Eat to Obtain Energy and Chemical Building Blocks
Concept 29.2: An Animal’s Energy Needs Depend on Physical Activity and Body Size
Concept 29.3: Metabolic Rates Are Affected by Homeostasis and by Regulation and Conformity
Concept 29.4: Animals Exhibit Division of Labor, but Each Cell Must Make Its Own ATP
Concept 29.5: The Phenotypes of Individual Animals Can Change during Their Lifetimes
Concept 29.6: Animal Function Requires Control Mechanisms
Summary
Nutrition, Feeding, and Digestion
Concept 30.1: Food Provides Energy and Chemical Building Blocks
Concept 30.2: Animals Get Food in Three Major Ways
Concept 30.3: The Digestive System Plays a Key Role in Determining the Nutritional Value of Foods
Concept 30.4: The Vertebrate Digestive System Is a Tubular Gut with Accessory Glands
Concept 30.5: The Processing of Meals Is Regulated
Summary
Breathing
Concept 31.1: Respiratory Gas Exchange Depends on Diffusion and Bulk Flow
Concept 31.2: Animals Have Evolved Diverse Types of Breathing Organs
Concept 31.3: The Mammalian Breathing System Is Anatomically and Functionally Elaborate
Summary
Circulation
Concept 32.1: Circulatory Systems Can Be Closed or Open
Concept 32.2: The Breathing Organs and Systemic Tissues Are Usually, but Not Always, in Series
Concept 32.3: A Beating Heart Propels the Blood
Concept 32.4: Many Key Processes Occur in the Vascular System
Concept 32.5: The Blood Transports O2 and CO2
Summary
Muscle and Movement
Concept 33.1: Muscle Cells Develop Forces by Means of Cycles of Protein–Protein Interaction
Concept 33.2: Skeletal Muscles Pull on Skeletal Elements to Produce Useful Movements
Concept 33.3: Skeletal Muscle Performance Depends on ATP Supply, Cell Type, and Training
Concept 33.4: Many Distinctive Types of Muscle Have Evolved
Summary
Neurons, Sense Organs, and Nervous Systems
Concept 34.1: Nervous Systems Are Composed of Neurons and Glial Cells
Concept 34.2: Neurons Generate Electric Signals by Controlling Ion Distributions
Concept 34.3: Neurons Communicate with Other Cells at Synapses
Concept 34.4: Sensory Processes Provide Information on an Animal’s External Environment and Internal Status
Concept 34.5: Neurons Are Organized into Nervous Systems
Summary
Control by the Endocrine and Nervous Systems
Concept 35.1: The Endocrine and Nervous Systems Play Distinct, Interacting Roles
Concept 35.2: Hormones Are Chemical Messengers Distributed by the Blood
Concept 35.3: The Vertebrate Hypothalamus and Pituitary Gland Link the Nervous and Endocrine Systems
Concept 35.4: Hormones Regulate Mammalian Physiological Systems
Concept 35.5: The Insect Endocrine System Is Crucial for Development
Summary
Water and Salt Balance
Concept 36.1: Kidneys Regulate the Composition of the Body Fluids
Concept 36.2: Nitrogenous Wastes Need to Be Excreted
Concept 36.3: Aquatic Animals Display a Wide Diversity of Relationships to Their Environment
Concept 36.4: Dehydration Is the Principal Challenge for Terrestrial Animals
Concept 36.5: Kidneys Adjust Water Excretion to Help Animals Maintain Homeostasis
Summary
Animal Reproduction
Concept 37.1: Sexual Reproduction Depends on Gamete Formation and Fertilization
Concept 37.2: The Mammalian Reproductive System Is Hormonally Controlled
Concept 37.3: Reproduction Is Integrated with the Life Cycle
Summary
Animal Development
Concept 38.1: Fertilization Activates Development
Concept 38.2: Cleavage Creates Building Blocks and Produces a Blastula
Concept 38.3: Gastrulation Produces a Second, then a Third Germ Layer
Concept 38.4: Gastrulation Sets the Stage for Organogenesis and Neurulation in Chordates
Concept 38.5: Extraembryonic Membranes Protect and Nourish the Embryo
Concept 38.6: Development Continues throughout Life
Summary
Immunology: Animal Defense Systems
Concept 39.1: Animals Use Innate and Adaptive Mechanisms to Defend Themselves against Pathogens
Concept 39.2: Innate Defenses Are Nonspecific
Concept 39.3: The Adaptive Immune Response Is Specific
Concept 39.4: The Adaptive Humoral Immune Response Involves Specific Antibodies
Concept 39.5: The Adaptive Cellular Immune Response Involves T Cells and Their Receptors
Summary
Animal Behavior
Concept 40.1: Behavior Is Controlled by the Nervous System but Is Not Necessarily Deterministic
Concept 40.2: Behavior Is Influenced by Development and Learning
Concept 40.3: Behavior Is Integrated with the Rest of Function
Concept 40.4: Moving through Space Presents Distinctive Challenges
Concept 40.5: Social Behavior Is Widespread
Concept 40.6: Behavior Helps Structure Ecological Communities and Processes
Summary
Ecology
The Distribution of Earth’s Ecological Systems
Concept 41.1: Ecological Systems Vary over Space and Time
Concept 41.2: Solar Energy Input and Topography Shape Earth’s Physical Environments
Concept 41.3: Biogeography Reflects Physical Geography
Concept 41.4: Biogeography Also Reflects Geological History
Concept 41.5: Human Activities Affect Ecological Systems on a Global Scale
Summary
Populations
Concept 42.1: Populations Are Patchy in Space and Dynamic over Time
Concept 42.2: Births Increase and Deaths Decrease Population Size
Concept 42.3: Life Histories Determine Population Growth Rates
Concept 42.4: Populations Grow Multiplicatively, but the Multiplier Can Change
Concept 42.5: Immigration and Emigration Affect Population Dynamics
Concept 42.6: Ecology Provides Tools for Conserving and Managing Populations
Summary
Ecological and Evolutionary Consequences of Interactions within and among Species
Concept 43.1: Interactions between Species May Increase, Decrease, or Have No Effect on Fitness
Concept 43.2: Interactions within and among Species Affect Population Dynamics and Species Distributions
Concept 43.3: Species Are Embedded in Complex Interaction Webs
Concept 43.4: Interactions within and among Species Can Result in Evolution
Summary
Ecological Communities
Concept 44.1: Communities Contain Species That Colonize and Persist
Concept 44.2: Communities Change over Space and Time
Concept 44.3: Community Structure Affects Community Function
Concept 44.4: Diversity Patterns Provide Clues to What Determines Diversity
Concept 44.5: Community Ecology Suggests Strategies for Conserving Community Function-
Summary
The Global Ecosystem
Concept 45.1: Climate and Nutrients Affect Ecosystem Function-
Concept 45.2: Biological, Geological, and Chemical Processes Move Materials through Ecosystems-
Concept 45.3: Certain Biogeochemical Cycles Are Especially Critical for Ecosystems
Concept 45.4: Biogeochemical Cycles Affect Global Climate
Concept 45.5: Rapid Climate Change Affects Species and Communities
Concept 45.6: Ecological Challenges Can Be Addressed through Science and International Cooperation
Summary
The Tree of Life
Making Sense of Data: A Statistics Primer
Some Measurements Used in Biology
Illustration Credits
Index