Biology : concepts and investigations

Title
Contents
UNIT 1 Science, Chemistry, and Cells
	1 | The Scientifi c Study of Life
		1.1 What Is Life?
			A. Life Is Organized
			B. Life Requires Energy
			C. Life Maintains Internal Constancy
			D. Life Reproduces Itself, Grows, and Develops
			E. Life Evolves
		1.2 The Tree of Life Includes Three Main Branches
		1.3 Scientists Study the Natural World
			A. The Scientifi c Method Has Multiple Interrelated Parts
			B. An Experimental Design Is a Careful Plan
			C. Theories Are Comprehensive Explanations
			D. Scientifi c Inquiry Has Limitations
		1.4 Investigating Life: The Orchid and the Moth
	2 | The Chemistry of LIfe
		2.1 Atoms Make Up All Matter
			A. Elements Are Fundamental Types of Matter
			B. Atoms Are Particles of Elements
			C. Isotopes Have Different Numbers of Neutrons
		2.2 Chemical Bonds Link Atoms
			A. Electrons Determine Bonding
			B. In a Covalent Bond, Atoms Share Electrons
			C. In an Ionic Bond, One Atom Transfers Electrons to Another Atom
			D. Partial Charges on Polar Molecules Create Hydrogen Bonds
		2.3 Water Is Essential to Life
			A. Water Is Cohesive and Adhesive
			B. Many Substances Dissolve in Water
			C. Water Regulates Temperature
			D. Water Expands as It Freezes
			E. Water Participates in Life’s Chemical Reactions
		2.4 Organisms Balance Acids and Bases
			A. The pH Scale Expresses Acidity or Alkalinity
			B. Buffer Systems Regulate pH in Organisms
		2.5 Organic Molecules Generate Life’s Form and Function
			A. Carbohydrates Include Simple Sugars and Polysaccharides
			B. Lipids Are Hydrophobic and Energy-Rich
			C. Proteins Are Complex and Highly Versatile
			D. Nucleic Acids Store and Transmit Genetic Information
		2.6 Investigating Life: E. T. and the Origin of Life
	3 | Cells
		3.1 Cells Are the Units of Life
			A. Simple Lenses Revealed the Cellular Basis of Life
			B. The Cell Theory Emerges
			C. Microscopes Magnify Cell Structures
			D. All Cells Have Features in Common
		3.2 Different Cell Types Characterize Life’s Three Domains
			A. Domain Bacteria Contains Earth’s Most Abundant Organisms
			B. Domain Archaea Includes Prokaryotes with Unique Biochemistry
			C. Domain Eukarya Contains Organisms with Complex Cells
		3.3 A Membrane Separates Each Cell from Its Surroundings
		3.4 Eukaryotic Organelles Divide Labor
			A. The Nucleus, Endoplasmic Reticulum, and Golgi Interact to Secrete Substances
			B. Lysosomes, Vacuoles, and Peroxisomes Are Cellular Digestion Centers
			C. Photosynthesis Occurs in Chloroplasts
			D. Mitochondria Extract Energy from Nutrients
		3.5 The Cytoskeleton Supports Eukaryotic Cells
		3.6 Cells Stick Together and Communicate with One Another
			A. Cell Walls Are Strong, Flexible, and Porous
			B. Animal Cell Junctions Occur in Several Forms
		3.7 Investigating Life: Did the Cytoskeleton Begin in Bacteria?
	4 | The Energy of Life
		4.1 All Cells Capture and Use Energy
			A. Energy Allows Cells to Do Life’s Work
			B. The Laws of Thermodynamics Describe Energy Transfer
		4.2 Networks of Chemical Reactions Sustain Life
			A. Chemical Reactions Absorb or Release Energy
			B. At Chemical Equilibrium, Reaction Rates Are in Balance
			C. Linked Oxidation and Reduction Reactions Form Electron Transport Chains
		4.3 ATP Is Cellular Energy Currency
			A. Coupled Reactions Release and Store Energy in ATP
			B. Transfer of Phosphate Completes the Energy Transaction
			C. ATP Represents Short-Term Energy Storage
		4.4 Enzymes Speed Biochemical Reactions
			A. Enzymes Bring Reactants Together
			B. Enzymes Have Partners
			C. Cells Control Reaction Rates in Metabolic Pathways
			D. Many Factors Affect Enzyme Activity
		4.5 Membrane Transport May Release Energy or Cost Energy
			A. Passive Transport Does Not Require Energy Input
			B. Active Transport Requires Energy Input
			C. Endocytosis and Exocytosis Use Vesicles to Transport Substances
		4.6 Investigating Life: Does Natural Selection Maintain Some Genetic Illnesses?
	5 | Photosynthesis
		5.1 Life Depends on Photosynthesis
			A. Photosynthesis Builds Carbohydrates Out of Carbon Dioxide and Water
			B. The Evolution of Photosynthesis Changed Planet Earth
		5.2 Sunlight Is the Energy Source for Photosynthesis
			A. What Is Light?
			B. Photosynthetic Pigments Capture Light Energy
			C. Chloroplasts Are the Sites of Photosynthesis
		5.3 Photosynthesis Occurs in Two Stages
		5.4 The Light Reactions Begin Photosynthesis
			A. Photosystem II Produces ATP
			B. Photosystem I Produces NADPH
		5.5 The Carbon Reactions Produce Carbohydrates
		5.6 C3 Plants Use Only the Calvin Cycle to Fix Carbon
		5.7 The Cand CAM Pathways Save Carbon and Water
		5.8 Investigating Life: Solar-Powered Sea Slugs
	6 | How Cells Release Energy
		6.1 Cells Use Energy in Food to Make ATP
		6.2 Cellular Respiration Includes Three Main Processes
		6.3 In Eukaryotic Cells, Mitochondria Produce Most ATP
		6.4 Glycolysis Breaks Down Glucose to Pyruvate
		6.5 Aerobic Respiration Yields Much More ATP than Glycolysis Alone
			A. Pyruvate Is Oxidized to Acetyl CoA
			B. The Krebs Cycle Produces ATP and Electron Carriers
			C. The Electron Transport Chain Drives ATP Formation
		6.6 How Many ATPs Can One Glucose Molecule Yield?
		6.7 Other Food Molecules Enter the Energy-Extracting Pathways
		6.8 Some Energy Pathways Do Not Require Oxygen
			A. Anaerobic Respiration Uses an Electron Acceptor Other than O2
			B. Fermenters Acquire ATP Only from Glycolysis
		6.9 Photosynthesis and Respiration Are Ancient Pathways
		6.10 Investigating Life: Plants’ “Alternative” Lifestyles Yield Hot Sex
UNIT 2 Biotechnology, Genetics, and Inheritance
	7 | DNA Structure and Gene Function
		7.1 Experiments Identifi ed the Genetic Material
			A. Bacteria Can Transfer Genetic Information
			B. Hershey and Chase Confi rmed the Genetic Role of DNA
		7.2 DNA Is a Double Helix of Nucleotides
		7.3 DNA Contains the “Recipes” for a Cell’s Proteins
			A. Protein Synthesis Requires Transcription and Translation
			B. RNA Is an Intermediary Between DNA and a Polypeptide Chain
		7.4 Transcription Uses a DNA Template to Create RNA
			A. Transcription Occurs in Three Steps
			B. mRNA Is Altered in the Nucleus of Eukaryotic Cells
		7.5 Translation Builds the Protein
			A. The Genetic Code Links mRNA to Protein
			B. Translation Requires mRNA, tRNA, and Ribosomes
			C. Translation Occurs in Three Steps
			D. Proteins Must Fold Correctly After Translation
		7.6 Cells Regulate Gene Expression
			A. Operons Are Groups of Bacterial Genes That Share One Promoter
			B. Eukaryotic Organisms Use Transcription Factors
			C. Eukaryotic Cells Also Use Additional Regulatory Mechanisms
		7.7 Mutations Change DNA Sequences
			A. Mutations Range from Silent to Devastating
			B. What Causes Mutations?
			C. Mutations May Pass to Future Generations
			D. Mutations Are Important
		7.8 The Human Genome Is Surprisingly Complex
		7.9 Genetic Engineering Moves Genes Among Species
			A. Transgenic Organisms Contain DNA from Multiple Species
			B. Creating Transgenic Organisms Requires Cutting and Pasting DNA
		7.10 Researchers Can Fix, Block, or Monitor Genes
			A. Gene Therapy Repairs Faulty Genes
				B. Antisense RNA and Gene Knockouts Block Gene Expression
				C. DNA Microarrays Help Monitor Gene Expression
		7.11 Investigating Life: Clues to the Origin of Language
	8 |  DNA Replication, Mitosis, and the Cell Cycle
		8.1 Cells Divide and Cells Die
			A. Sexual Life Cycles Include Mitosis, Meiosis, and Fertilization
			B. Cell Death Is Part of Life
		8.2 DNA Replication Precedes Cell Division
		8.3 Replicated Chromosomes Condense as a Cell Prepares to Divide
		8.4 Mitotic Division Generates Exact Cell Copies
			A. Interphase Is a Time of Great Activity
			B. Chromosomes Divide During Mitosis
			C. The Cytoplasm Splits in Cytokinesis
		8.5 Cancer Arises When Cells Divide out of Control
			A. Chemical Signals Regulate Cell Division
			B. Cancer Cells Break Through Cell Cycle Controls
			C. Cancer Cells Differ from Normal Cells in Many Ways
			D. Inheritance and Environment Both Can Cause Cancer
			E. Cancer Treatments Remove or Kill Abnormal Cells
		8.6 Apoptosis Is Programmed Cell Death
		8.7 Stem Cells and Cloning Present Ethical Dilemmas
			A. Stem Cells Divide to Form Multiple Cell Types
			B. Cloning Creates Identical Copies of an Organism
		8.8 Several Technologies Use DNA Replication Enzymes
			A. DNA Sequencing Reveals the Order of Bases
			B. PCR Replicates DNA in a Test Tube
			C. DNA Profi ling Has Many Applications
		8.9 Investigating Life: Cutting Off a Tumor’s Supply Lines in the War on Cancer
	9 | Sexual Reproduction and Meiosis
		9.1 Why Sex?
		9.2 Diploid Cells Contain Two Homologous Sets of Chromosomes
		9.3 Meiosis Is Essential in Sexual Reproduction
			A. Gametes Are Haploid Sex Cells
			B. Specialized Germ Cells Undergo Meiosis
			C. Meiosis Halves the Chromosome Number and Scrambles Alleles
		9.4 In Meiosis, DNA Replicates Once, but the Nucleus Divides Twice
			A. In Meiosis I, Homologous Chromosomes Pair Up and Separate
			B. Meiosis II Yields Four Haploid Cells
		9.5 Meiosis Generates Enormous Variability
			A. Crossing Over Shuffl es Genes
			B. Chromosome Pairs Align Randomly During Metaphase I
			C. Random Fertilization Multiplies the Diversity
		9.6 Mitosis and Meiosis Have Different Functions: A Summary
		9.7 Errors Sometimes Occur in Meiosis
			A. Polyploidy Means Extra Chromosome Sets
			B. Nondisjunction Results in Extra or Missing Chromosomes
			C. Smaller-Scale Chromosome Abnormalities Also Occur
		9.8 Haploid Nuclei Are Packaged into Gametes
			A. In Humans, Gametes Form in Testes and Ovaries
			B. In Plants, Gametophytes Produce Gametes
		9.9 Investigating Life: A New Species Is Born, but Who’s the Daddy?
	10 | Patterns of Inheritance
		10.1 Chromosomes Are Packets of Genetic Information: A Review
		10.2 Mendel’s Experiments Uncovered Basic Laws of Inheritance
			A. Why Peas?
				B. Dominant Alleles Appear to Mask Recessive Alleles
				C. For Each Gene, a Cell’s Two Alleles May Be Identical or Different
				D. Every Generation Has a Name
		10.3 The Two Alleles of Each Gene End Up in Different Gametes
			A. Monohybrid Crosses Track the Inheritance of One Gene
				B. Meiosis Explains Mendel’s Law of Segregation
		10.4 Genes on Different Chromosomes Are Inherited Independently
			A. Dihybrid Crosses Track the Inheritance of Two Genes at Once
				B. Meiosis Explains Mendel’s Law of Independent Assortment
		10.5 Genes on the Same Chromosome May Be Inherited Together
			A. Genes on the Same Chromosome Are Linked
				B. Studies of Linked Genes Have Yielded Chromosome Maps
		10.6 Gene Expression Can Appear to Alter Mendelian Ratios
			A. Incomplete Dominance and Codominance Add Phenotype Classes
				B. Some Inheritance Patterns Are Especially Diffi cult to Interpret
		10.7 Sex-Linked Genes Have Unique Inheritance Patterns
			A. X and Y Chromosomes Determine Sex in Humans
			B. X-Linked Recessive Disorders Affect More Males Than Females
			C. X Inactivation Prevents “Double Dosing” of Proteins
		10.8 Pedigrees Show Modes of Inheritance
		10.9 Most Traits Are Infl uenced by the Environment and Multiple Genes
			A. The Environment Can Alter the Phenotype
			B. Polygenic Traits Depend on More Than One Gene
		10.10 Investigating Life: Heredity and the Hungry Hordes
UNIT 3 The Evolution of Life
	11 | The Forces of Evolutionary Change
		11.1 Evolutionary Thought Has Evolved for Centuries
			A. Many Explanations Have Been Proposed for Life’s Diversity
			B. Charles Darwin’s Voyage Provided a Wealth of Evidence
			C. On the Origin of Species Proposed Natural Selection as an Evolutionary Mechanism
			D. Evolutionary Theory Continues to Expand
		11.2 Natural Selection Molds Evolution
			A. Adaptations Enhance Reproductive Success
			B. Natural Selection Eliminates Phenotypes
			C. Natural Selection Does Not Have a Goal
			D. What Does “Survival of the Fittest” Really Mean?
		11.3 Evolution Is Inevitable in Real Populations
			A. At Hardy–Weinberg Equilibrium, Allele Frequencies Do Not Change
			B. In Reality, Allele Frequencies Always Change
		11.4 Natural Selection Can Shape a Population in Many Ways
		11.5 Sexual Selection Directly Infl uences Reproductive Success
		11.6 Evolution Occurs in Several Additional Ways
			A. Mutation Fuels Evolution
			B. Genetic Drift Occurs by Chance
			C. Nonrandom Mating Concentrates Alleles Locally
			D. Gene Flow Moves Alleles Between Populations
		11.7 Investigating Life: Size Matters in Fishing Frenzy
	12 | Evidence of Evolution
		12.1 Clues to Evolution Lie in the Earth, Body Structures, and Molecules
		12.2 Fossils Record Evolution
			A. Fossils Form in Many Ways
			B. The Fossil Record Is Often Incomplete
			C. The Age of a Fossil Can Be Estimated in Two Ways
		12.3 Biogeography Considers Species’ Geographical Locations
			A. The Theory of Plate Tectonics Explains Earth’s Shifting Continents
			B. Species Distributions Reveal Evolutionary Events
		12.4 Anatomical Comparisons May Reveal Common Descent
			A. Homologous Structures Have a Shared Evolutionary Origin
			B. Vestigial Structures Have Lost Their Functions
			C. Convergent Evolution Produces Superfi cial Similarities
		12.5 Embryonic Development Patterns Provide Evolutionary Clues
		12.6 Molecules Reveal Relatedness
			A. Comparing DNA and Protein Sequences May Reveal Close Relationships
			B. Molecular Clocks Help Assign Dates to Evolutionary Events
		12.7 Investigating Life: Darwin’s Finches Reveal Ongoing Evolution
	13 | Speciation and Extinction
		13.1 The Defi nition of “Species” Has Evolved over Time
			A. Linnaeus Devised the Binomial Naming System
			B. Ernst Mayr Developed the Biological Species Concept
		13.2 Reproductive Barriers Cause Species to Diverge
			A. Prezygotic Barriers Prevent Fertilization
			B. Postzygotic Barriers Prevent Viable or Fertile Offspring
		13.3 Spatial Patterns Defi ne Three Types of Speciation
			A. Allopatric Speciation Refl ects a Geographic Barrier
			B. Parapatric Speciation Occurs in Neighboring Regions
			C. Sympatric Speciation Occurs in a Shared Habitat
			D. Determining the Type of Speciation May Be Diffi cult
		13.4 Speciation May Be Gradual or Occur in Bursts
			A. Gradualism and Punctuated Equilibrium Are Two Models of Speciation
			B. Bursts of Speciation Occur During Adaptive Radiation
		13.5 Extinction Marks the End of the Line
			A. Many Factors Can Combine to Put a Species at Risk
			B. Extinction Rates Have Varied over Time
		13.6 Biological Classifi cation Systems Are Based on Common Descent
			A. The Taxonomic Hierarchy Organizes Species into Groups
			B. A Cladistics Approach Is Based on Shared Derived Traits
			C. Cladograms Depict Hypothesized Evolutionary Relationships
			D. Many Traditional Groups Are Not Monophyletic
		13.7 Investigating Life: Birds Do It, Bees Do It
	14 The Origin and History of Life
		14 | 14.1 Life’s Origin Remains Mysterious
			A. The First Organic Molecules May Have Formed in a Chemical “Soup”
			B. Some Investigators Suggest an “RNA World”
			C. Membranes Enclosed the Molecules
			D. The Origin of Metabolism Would Have Involved Early Enzymes
			E. Early Life Changed Earth Forever
		14.2 Complex Cells and Multicellularity Arose over a Billion Years Ago
			A. Endosymbiosis Explains the Origin of Mitochondria and Chloroplasts
			B. Multicellularity May Also Have Its Origin in Cooperation
		14.3 Life’s Diversity Exploded in the Past 500 Million Years
			A. The Strange Ediacarans Flourished Late in the Precambrian
			B. Paleozoic Plants and Animals Emerged onto Land
			C. Reptiles and Flowering Plants Thrived During the Mesozoic Era
			D. Mammals Diversifi ed During the Cenozoic Era
		14.4 Fossils and DNA Tell the Human Evolution Story
			A. Humans Are Primates
			B. Molecular Evidence Documents Primate Relationships
			C. Hominine Evolution Is Partially Recorded in Fossils
			D. Environmental Changes Have Spurred Hominine Evolution
			E. Migration and Culture Have Changed Homo sapiens
		14.5 Investigating Life: What Makes Us Human?
UNIT 4 The Diversity of Life
	15 | Viruses
		15.1 Viruses Are Infectious Particles of Genetic Information and Protein
			A. Viruses Are Smaller and Simpler Than Cells
			B. A Virus’s Host Range Consists of the Organisms It Infects
			C. Are Viruses Alive?
		15.2 Viral Replication Occurs in Five Stages
		15.3 Cell Death May Be Immediate or Delayed
			A. Some Viruses Kill Cells Immediately
			B. Viral DNA Can “Hide” in a Cell
		15.4 Effects of a Viral Infection May Be Mild or Severe
			A. Symptoms Result from Cell Death and the Immune Response
			B. Some Animal Viruses Linger for Years
			C. Drugs and Vaccines Help Fight Viral Infections
		15.5 Viruses Cause Diseases in Plants
		15.6 Viroids and Prions Are Other Noncellular Infectious Agents
			A. A Viroid Is an Infectious RNA Molecule
			B. A Prion Is an Infectious Protein
		15.7 Investigating Life: Scientifi c Detectives Follow HIV’s Trail
	16 | and Archaea
		Bacteria 16.1 Prokaryotes Are a Biological Success Story
		16.2 Prokaryote Classifi cation Traditionally Relies on Visible Features
			A. Microscopes Reveal Cell Structures
			B. Metabolic Pathways May Be Useful in Classifi cation
			C. Molecular Data Reveal Evolutionary Relationships
		16.3 Prokaryotes Transmit DNA Vertically and Horizontally
		16.4 Prokaryotes Include Two Domains with Enormous Diversity
			A. Domain Bacteria Includes Many Familiar Groups
			B. Many, But Not All, Archaea Are “Extremophiles”
		16.5 Bacteria and Archaea Are Important to Human Life
			A. Microbes Form Vital Links in Ecosystems
			B. Bacteria and Archaea Live in and on Us
			C. Humans Put Many Prokaryotes to Work
		16.6 Investigating Life: A Bacterial Genome Solves Two Mysteries
	17 | Protists
		17.1 Protists Lie at the Crossroads Between Simple and Complex Organisms
			A. What Is a Protist?
			B. Protists Are Important in Many Ways
			C. Protists Have a Lengthy Evolutionary History
		17.2 Many Protists Are Photosynthetic
			A. Euglenoids Are Heterotrophs and Autotrophs
			B. Dinofl agellates Are “Whirling Cells”
			C. Golden Algae, Diatoms, and Brown Algae Contain Yellowish Pigments
			D. Red Algae Can Live in Deep Water
			E. Green Algae Are the Closest Relatives of Plants
		17.3 Some Heterotrophic Protists Were Once Classifi ed as Fungi
			A. Slime Molds Are Unicellular and Multicellular
			B. Water Molds Are Decomposers and Parasites
		17.4 Protozoa Are Diverse Heterotrophic Protists
			A. Several Flagellated Protozoa Cause Disease
			B. Amoeboid Protozoa Produce Pseudopodia
			C. Ciliates Are Common Protozoa with Complex Cells
			D. Apicomplexans Include Nonmotile Animal Parasites
		17.5 Protist Classifi cation Is Changing Rapidly
		17.6 Investigating Life: Glassy Fossils Reveal the Birth of a Species
	18 |  Plants
		18.1 Plants Have Changed the World
			A. Green Algae Are the Closest Relatives of Plants
			B. Plants Are Adapted to Life on Land
		18.2 Bryophytes Are the Simplest Plants
			A. Bryophytes Are Small and Lack Vascular Tissue
			B. Bryophytes Have a Conspicuous Gametophyte
		18.3 Seedless Vascular Plants Have Xylem and Phloem but No Seeds
			A. Seedless Vascular Plants Include Ferns and Their Close Relatives
			B. Seedless Vascular Plants Have a Conspicuous Sporophyte
		18.4 Gymnosperms Are “Naked Seed” Plants
			A. Gymnosperms Include Conifers and Three Related Groups
			B. Conifers Produce Pollen and Seeds in Cones
		18.5 Angiosperms Produce Seeds in Fruits
			A. Most Angiosperms Are Eudicots or Monocots
			B. Flowers and Fruits Are Unique to the Angiosperm Life Cycle
			C. Animals Often Participate in Angiosperm Reproduction
		18.6 Investigating Life: Genetic Messages from the Dead Tell Tales of Ancient Ecosystems
	19 | Fungi
		19.1 Fungi Are Essential Decomposers
			A. Fungi Are Eukaryotic Heterotrophs That Digest Food Externally
			B. Fungal Classifi cation Is Traditionally Based on Reproductive Structures
		19.2 Chytridiomycetes Produce Swimming Spores
		19.3 Zygomycetes Are Fast Growing and Prolifi c
		19.4 Glomeromycetes Colonize Living Plant Roots
		19.5 Ascomycetes Are the Sac Fungi
		19.6 Basidiomycetes Are the Familiar Club Fungi
		19.7 Fungi Interact with Other Organisms
			A. Endophytes Live in Aerial Plant Parts
			B. Mycorrhizal Fungi Live on or in Roots
			C. Some Ants Cultivate Fungi
			D. Lichens Are Distinctive Dual Organisms
		19.8 Investigating Life: The Battle for Position in Cacao Tree Leaves
	20 | Animals
		20.1 Animals Live Nearly Everywhere
			A. The First Animals Likely Evolved from Protists
			B. Animals Share Several Characteristics
			C. Biologists Classify Animals Based on Organization, Morphology, and Development
			D. Biologists Also Consider Additional Characteristics
		20.2 Sponges Are Simple Animals That Lack Differentiated Tissues
		20.3 Cnidarians Are Radially Symmetrical, Aquatic Animals
		20.4 Flatworms Have Bilateral Symmetry and Incomplete Digestive Tracts
		20.5 Mollusks Are Soft, Unsegmented Bodies
		20.6 Annelids Are Segmented Worms
		20.7 Nematodes Are Unsegmented, Cylindrical Worms
		20.8 Arthropods Have Exoskeletons and Jointed Appendages
			A. Arthropods Have Complex Organ Systems
			B. Arthropods Are the Most Diverse Animals
		20.9 Echinoderms Have Five-Part, Radial Symmetry
		20.10 Most Chordates Are Vertebrates
			A. Four Features Distinguish Chordates
			B. Biologists Use Many Features to Classify Chordates
		20.11 Tunicates and Lancelets Have Neither Cranium nor Backbone
		20.12 Hagfi shes Have a Cranium but Lack a Backbone
		20.13 Fishes Are Aquatic Vertebrates with Gills and Fins
			A. Fishes Changed the Course of Vertebrate Evolution
			B. Fishes May or May Not Have Jaws
		20.14 Amphibians Lead a Double Life on Land and in Water
			A. Amphibians Were the First Tetrapods
			B. Amphibians Include Three Main Lineages
		20.15 Reptiles Were the First Vertebrates to Thrive on Dry Land
			A. Nonavian Reptiles Include Four Main Groups
			B. Birds Are Warm, Feathered Reptiles
		20.16 Mammals Are Warm, Furry Milk-Drinkers
			A. Mammals Share a Common Ancestor with Reptiles
			B. Mammals Lay Eggs or Bear Live Young
		20.17 Investigating Life: Limbs Gained and Limbs Lost
UNIT 5 Plant Life Plant Form and Function
	21 | Plant Form and Function
		21 | 21.1 Vegetative Plant Parts Include Stems, Leaves, and Roots
		21.2 Plants Have Flexible Growth Patterns, Thanks to Meristems
			A. Plants Grow by Adding New Modules
			B. Plant Growth Occurs at Meristems
		21.3 Plant Cells Build Tissues
			A. Plants Have Several Cell Types
			B. Plant Cells Form Three Main Tissue Systems
		21.4 Tissues Build Stems, Leaves, and Roots
			A. Stems Support Leaves
			B. Leaves Are the Primary Organs of Photosynthesis
			C. Roots Absorb Water and Minerals, and Anchor the Plant
		21.5 Lateral Meristems Produce Wood and Bark
			A. The Vascular Cambium Produces Xylem and Phloem in Woody Plants
			B. The Cork Cambium Produces the Outer Layer of a Woody Stem or Root
			C. Wood Is Durable and Useful
		21.6 Investigating Life: An Army of Tiny Watchdogs
	22 | Plant Nutrition and Transport
		22.1 Soil and Air Provide Water and Nutrients
			A. Plants Require 16 Essential Elements
			B. Soils Have Distinct Layers
			C. Leaves and Roots Absorb Essential Elements
		22.2 Water and Dissolved Minerals Are Pulled Up to Leaves
			A. Water Vapor Is Lost from Leaves Through Transpiration
			B. Xylem Transport Relies on Cohesion
			C. The Cuticle and Stomata Help Conserve Water
		22.3 Organic Compounds Are Pushed to Nonphotosynthetic Cells
			A. Phloem Sap Contains Sugars and Other Organic Compounds
			B. The Pressure Flow Theory Explains Phloem Function
		22.4 Parasitic Plants Tap into Another Plant’s Vascular Tissue
		22.5 Investigating Life: The Hidden Cost of Traps
	23 | Reproduction and Development of Flowering Plants
		23.1 Angiosperms Reproduce Asexually and Sexually
			A. Asexual Reproduction Yields Clones
			B. Sexual Reproduction Generates Variability
		23.2 The Angiosperm Life Cycle Includes Flowers, Fruits, and Seeds
			A. Flowers Are Reproductive Organs
			B. The Pollen Grain and Embryo Sac Are Gametophytes
			C. Pollination Brings Pollen to the Stigma
			D. Double Fertilization Yields Zygote and Endosperm
			E. A Seed Is an Embryo and Its Food Supply Inside a Seed Coat
			F. The Fruit Develops from the Ovary
			G. Fruits Protect and Disperse Seeds
		23.3 Plant Growth Begins with Seed Germination
		23.4 Hormones Regulate Plant Growth and Development
			A. Auxins and Cytokinins Are Essential for Plant Growth
			B. Gibberellins, Ethylene, and Abscisic Acid Infl uence Plant Development in Many Ways
			C. Biologists Continue to Discover Additional Plant Hormones
		23.5 Light Is a Powerful Infl uence on Plant Life
			A. Phototropism Is Growth Toward Light
			B. Phytochrome Regulates Seed Germination, Daily Rhythms, and Flowering
		23.6 Plants Respond to Gravity and Touch
		23.7 Plant Parts Die or Become Dormant
		23.8 Investigating Life: A Red Hot Chili Pepper Paradox
UNIT 6 Animal Life | Animal Tissues and Organ Systems
	24 | Animal and Organ Systems
		24.1 Specialized Cells Build Animal Bodies
		24.2 Animals Consist of Four Tissue Types
			A. Epithelial Tissue Covers Surfaces
			B. Most Connective Tissues Bind Other Tissues Together
			C. Muscle Tissue Provides Movement
			D. Nervous Tissue Forms a Rapid Communication Network
		24.3 Organ Systems Are Interconnected
			A. The Nervous and Endocrine Systems Coordinate Communication
			B. The Skeletal and Muscular Systems Support and Move the Body
			C. The Digestive, Circulatory, and Respiratory Systems Work Together to Acquire Energy
			D. The Urinary, Integumentary, Immune, and Lymphatic Systems Protect the Body
			E. The Reproductive System Produces the Next Generation
		24.4 Organ System Interactions Promote Homeostasis
		24.5 The Integumentary System Regulates Temperature and Conserves Moisture
		24.6 Investigating Life: Vitamins and the Evolution of Human Skin Pigmentation
	25 | The Nervous System
		25.1 The Nervous System Forms a Rapid Communication Network
			A. Invertebrates Have Nerve Nets, Nerve Ladders, or Nerve Cords
			B. Vertebrate Nervous Systems Are Highly Centralized
		25 .2 Neurons Are Functional Units of a Nervous System
			A. A Typical Neuron Consists of a Cell Body, Dendrites, and an Axon
			B. The Nervous System Includes Three Classes of Neurons
		25.3 Action Potentials Convey Messages
			A. A Neuron at Rest Has a Negative Charge
			B. A Neuron Transmitting an Impulse Undergoes a Wave of Depolarization
			C. The Myelin Sheath Speeds Impulse Conduction
		25.4 Neurotransmitters Pass the Message from Cell to Cell
			A. Neurons Communicate at Synapses
			B. The Postsynaptic Cell Integrates Signals from Multiple Synapses
		25.5 The Peripheral Nervous System Consists of Nerve Cells Outside the Central Nervous System
		25.6 The Central Nervous System Consists of the Spinal Cord and Brain
			A. The Spinal Cord Transmits Information Between Body and Brain
			B. The Human Brain Is Divided into Several Regions
			C. Many Brain Regions Participate in Memory Formation
			D. Damage to the Central Nervous System Can Be Devastating
		25.7 Investigating Life: The Nerve of Those Clams!
	26 | The Senses
		26.1 Diverse Senses Operate by the Same Principles
			A. Sensory Receptors Respond to Stimuli by Generating Action Potentials
			B. Continuous Stimulation May Cause Sensory Adaptation
		26.2 The General Senses Detect Touch, Temperature, Pain, and Position
		26.3 The Senses of Smell and Taste Detect Chemicals
			A. Chemoreceptors in the Nose Detect Odor Molecules
			B. Chemoreceptors in the Mouth Detect Taste
		26.4 Vision Depends on Light-Sensitive Cells
			A. Invertebrate Eyes Take Many Forms
			B. In the Vertebrate Eye, Light Is Focused on the Retina
			C. Signals Travel from the Retina to the Optic Nerve and Brain
		26.5 The Senses of Hearing and Equilibrium Begin in the Ears
			A. Mechanoreceptors in the Inner Ear Detect Sound Waves
			B. The Inner Ear Also Provides the Sense of Equilibrium
		26.6 Investigating Life: Unraveling the Mystery of the Origin of the Eye
	27 | The Endocrine System
		27.1 The Endocrine System Uses Hormones to Communicate
			A. Endocrine Glands Secrete Hormones That Interact with Target Cells
			B. The Nervous and Endocrine Systems Work Together
		27.2 Hormones Stimulate Responses in Target Cells
			A. Water-Soluble Hormones Trigger Second Messenger Systems
			B. Lipid-Soluble Hormones Directly Alter Gene Expression
		27.3 The Hypothalamus and Pituitary Gland Oversee Endocrine Control
			A. The Posterior Pituitary Stores and Releases Two Hormones
			B. The Anterior Pituitary Produces and Secretes Six Hormones
		27.4 Hormones from Many Glands Regulate Metabolism
			A. The Thyroid Gland Sets the Metabolic Pace
			B. The Parathyroid Glands Control Calcium Level
			C. The Adrenal Glands Coordinate the Body’s Stress Responses
			D. The Pancreas Regulates Nutrient Use
			E. The Pineal Gland Secretes Melatonin
		27.5 Hormones from the Ovaries and Testes Control Reproduction
		27.6 Investigating Life: Something’s Fishy in Evolution — The Origin of the Parathyroid Gland
	28 | The Skeletal and Muscular Systems
		28.1 Skeletons Take Many Forms
		28.2 The Vertebrate Skeleton Features a Central Backbone
		28.3 Bones Provide Support, Protect Internal Organs, and Supply Calcium
			A. Bones Consist Mostly of Bone Tissue and Cartilage
			B. Bones Are Constantly Built and Degraded
			C. Bones Help Regulate Calcium Homeostasis
			D. Bone Meets Bone at a Joint
		28.4 Muscle Movement Requires Contractile Proteins, Calcium, and ATP
			A. Actin and Myosin Filaments Fill Muscle Cells
			B. Sliding Filaments Are the Basis of Muscle Fiber Contraction
			C. Motor Neurons Stimulate Muscle Fiber Contraction
		28.5 Muscle Fibers Generate ATP in Many Ways
		28.6 Many Muscle Fibers Combine to Form One Muscle
			A. Each Muscle May Contract with Variable Force
			C. Muscles Contain Slow-Twitch and Fast-Twitch Fibers
			D. Exercise Strengthens Muscles
		28.7 Investigating Life: Did a Myosin Gene Mutation Make Humans Brainier?
	29 | The Circulatory System
		29.1 Circulatory Systems Deliver Nutrients and Remove Wastes
			A. Circulatory Systems Are Open or Closed
			B. Vertebrate Circulatory Systems Have Become Increasingly Complex
		29.2 Blood Is a Complex Mixture
			A. Plasma Carries Many Dissolved Substances
			B. Red Blood Cells Transport Oxygen
			C. White Blood Cells Fight Infection
			D. Blood Clotting Requires Platelets and Plasma Proteins
		29.3 Blood Circulates Through the Heart and Blood Vessels
		29.4 The Human Heart Is a Muscular Pump
			A. The Heart Has Four Chambers
			B. The Right and Left Halves of the Heart Deliver Blood Along Different Paths
			C. Cardiac Muscle Cells Produce the Heartbeat
			D. Exercise Strengthens the Heart
		29.5 Blood Vessels Form the Circulation Pathway
			A. Arteries, Capillaries, and Veins Have Different Structures
			B. Blood Pressure and Velocity Differ Among Vessel Types
		29.6 The Lymphatic System Maintains Circulation and Protects Against Infection
		29.7 Investigating Life: In (Extremely) Cold Blood
	30 | The Respiratory System
		30.1 Gases Diffuse Across Respiratory Surfaces
			A. Some Invertebrates Exchange Gases Across the Body Wall or in Internal Tubules
			B. Gills Exchange Gases with Water
			C. Terrestrial Vertebrates Exchange Gases in Lungs
		30.2 The Human Respiratory System Delivers Air to the Lungs
			A. The Nose, Pharynx, and Larynx Form the Upper Respiratory Tract
			B. The Lower Respiratory Tract Consists of the Trachea and Lungs
		30.3 Breathing Requires Pressure Changes in the Lungs
		30.4 Blood Delivers Oxygen and Removes Carbon Dioxide
			A. Blood Carries Gases in Several Forms
			B. Blood Gas Levels Help Regulate the Breathing Rate
		30.5 Investigating Life: Why Do Bugs Hold Their Breath?
	31 | Digestion and Nutrition
		31.1 Digestive Systems Derive Nutrients from Food
			A. Animals Eat to Obtain Energy and Building Blocks
			B. How Much Food Does an Animal Need?
			C. Animals Process Food in Four Stages
			D. Animal Diets and Feeding Strategies Vary Greatly
		31.2 Animal Digestive Tracts Take Many Forms
		31.3 The Human Digestive System Consists of Several Organs
			A. Digestion Begins in the Mouth and Esophagus
			B. The Stomach Stores, Digests, and Pushes Food
			C. The Small Intestine Digests and Absorbs Nutrients
			D. The Large Intestine Completes Nutrient and Water Absorption
		31.4 A Healthy Diet Includes Essential Nutrients and the Right Number of Calories
			A. A Varied Diet Is Essential to Good Health
			B. Body Weight Refl ects Food Intake and Activity Level
			C. Starvation: Too Few Calories to Meet the Body’s Needs
			D. Obesity: More Calories Than the Body Needs
		31.5 Investigating Life: The Ultimate Sacrifi ce
	32 | Regulation of Temperature and Body Fluids
		32.1 Animals Regulate Their Internal Temperature
			A. Heat Gains and Losses Determine an Animal’s Body Temperature
			B. Several Adaptations Help an Animal to Adjust Its Temperature
		32.2 Animals Regulate Water and Ions in Body Fluids
		32.3 Nitrogenous Wastes Include Ammonia, Urea, and Uric Acid
		32.4 The Urinary System Produces, Stores, and Eliminates Urine
		32.5 The Nephron Is the Functional Unit of the Kidney
			A. Nephrons Interact Closely with Blood Vessels
			B. Urine Formation Includes Filtration, Reabsorption, and Secretion
			C. The Glomerular Capsule Filters Blood
			D. Reabsorption and Secretion Occur in the Renal Tubule
			E. The Collecting Duct Conserves More Water
			F. Hormones Regulate Kidney Function
		32.6 Investigating Life: Sniffi ng Out the Origin of Fur and Feathers
	33 | The Immune System
		33.1 Many Cells, Tissues, and Organs Defend the Body
			A. White Blood Cells and Macrophages Play Major Roles in the Immune System
			B. The Lymphatic System Consists of Several Tissues and Organs
			C. The Immune System Has Two Main Subdivisions
		33.2 Innate Defenses Are Nonspecifi c and Act Early
			A. Barriers Form the First Line of Defense
			B. White Blood Cells and Macrophages Destroy Invaders
			C. Redness and Swelling Indicate Infl ammation
			D. Complement Proteins and Cytokines Are Chemical Defenses
			E. Fever Helps Fight Infection
		33.3 Adaptive Immunity Defends Against Specifi c Pathogens
			A. Macrophages Trigger Both Cell-Mediated and Humoral Immunity
			B. T Cells Coordinate Cell-Mediated Immunity
			C. B Cells Direct the Humoral Immune Response
			D. The Immune Response Turns Off Once the Threat Is Gone
			E. The Secondary Immune Response Is Stronger Than the Primary Response
		33.4 Vaccines Jump-Start Immunity
		33.5 Several Disorders Affect the Immune System
			A. Autoimmune Disorders Are Devastating and Mysterious
			B. Immunodefi ciencies Lead to Opportunistic Infections
			C. Allergies Misdirect the Immune Response
			D. A Pregnant Woman’s Immune System May Attack Her Fetus
		33.6 Investigating Life: The Hidden Cost of Hygiene
	34 | Animal Reproduction and Development
		34.1 Animal Development Begins with Reproduction
			A. Reproduction Is Asexual or Sexual
			B. Gene Expression Dictates Animal Development
			C. Development Is Indirect or Direct
		34.2 Males Produce Sperm Cells
			A. Male Reproductive Organs Are Inside and Outside the Body
			B. Spermatogenesis Yields Sperm Cells
			C. Hormones Infl uence Male Reproductive Function
		34.3 Females Produce Egg Cells
			A. Female Reproductive Organs Are Inside the Body
			B. Oogenesis Yields Egg Cells
			C. Hormones Infl uence Female Reproductive Function
			D. Hormonal Fluctuations Can Cause Discomfort
			E. Contraceptives Prevent Pregnancy
		34.4 Sexual Activity May Transmit Disease
		34.5 The Human Infant Begins Life as a Zygote
			A. Fertilization Joins Genetic Packages and Initiates Pregnancy
			B. Preembryonic Events Include Cleavage, Implantation, and Gastrulation
			C. Organs Take Shape During the Embryonic Stage
			D. Organ Systems Become Functional in the Fetal Stage
			E. Muscle Contractions in the Uterus Drive Labor and Childbirth
		34.6 Birth Defects Have Many Causes
		34.7 Investigating Life: The “Cross-Dressers” of the Reef
UNIT 7 Behavior and Ecology
	35 | Animal Behavior
		35.1 Animal Behaviors Have Proximate and Ultimate Causes
		35.2 Animal Behaviors Combine Innate and Learned Components
			A. Innate Behaviors Do Not Require Experience
			B. Learning Requires Experience
			C. Genes and Environment Interact to Determine Behavior
		35.3 Many Behaviors Improve Survival
			A. Some Animals Can Find Specifi c Locations
			B. Animals Balance the Energy Content and Costs of Acquiring Food
			C. Avoiding Predation Is Another Key to Survival
		35.4 Many Behaviors Promote Reproductive Success
			A. Courtship Sets the Stage for Mating
			B. Sexual Selection Leads to Differences Between the Sexes
			C. Animals Differ in Mating Systems and Degrees of Parental Care
			D. Human Reproductive Choices May Refl ect Natural Selection
		35.5 Social Behaviors Often Occur in Groups
			A. Group Living Has Costs and Benefi ts
			B. Dominance Hierarchies and Territoriality Reduce Competition
			C. Kin Selection and Reciprocal Altruism Explain Some Acts of Cooperation
			D. Eusocial Animals Have Highly Developed Societies
		35.6 Investigating Life: Addicted to Affection
	36 | Population Ecology
		36.1 A Population Consists of Individuals of One Species
			A. Density and Distribution Patterns Are Static Measures of a Population
			B. Isolated Subpopulations May Evolve into New Species
		36.2 Births and Deaths Help Determine Population Size
			A. Births Add Individuals to a Population
			B. Survivorship Curves Show the Probability of Dying at a Given Age
		36.3 Population Growth May Be Exponential or Logistic
			A. Growth Is Exponential When Resources Are Unlimited
			B. Population Growth Eventually Slows
			C. Many Conditions Limit Population Size
		36.4 Natural Selection Infl uences Life Histories
			A. Organisms Balance Reproduction Against Other Requirements
			B. r- and K-Selected Species Differ in the Trade-Off Between Quantity and Quality
			C. Guppies Illustrate the Importance of Natural Selection
		36.5 The Human Population Continues to Grow
			A. Population Dynamics Refl ect the Demographic Transition
			B. The Ecological Footprint Is an Estimate of Resource Use
		36.6 Investigating Life: Let Your Love Light Shine
	37 | Communities and Ecosystems
		37.1 Multiple Species Interact in Communities
			A. Populations Interact in Many Ways
			B. A Keystone Species Has a Pivotal Role in the Community
			C. Closely Interacting Species May Coevolve
		37.2 Communities Change over Time
		37.3 Ecosystems Require Continuous Energy Input
			A. Food Webs Depict the Transfer of Energy and Atoms
			B. Every Trophic Level Loses Energy
			C. Harmful Chemicals May Accumulate in the Highest Trophic Levels
		37.4 Chemicals Cycle Within Ecosystems
			A. Water Circulates Between the Land and the Atmosphere
			B. Autotrophs Obtain Carbon as CO2
			C. The Nitrogen Cycle Relies on Bacteria
			D. The Phosphorus Cycle Begins with the Weathering of Rocks
			E. Terrestrial and Aquatic Ecosystems Are Linked in Surprising Ways
		37.5 Investigating Life: Two Kingdoms and a Virus Team Up to Beat the Heat
	38 | Biomes
		38.1 The Physical Environment Determines Where Life Exists
		38.2 Earth Has Diverse Climates
		38.3 Terrestrial Biomes Range from the Lush Tropics to the Frozen Tundra
			A. Towering Trees Dominate the Forests
			B. Grasslands Occur in Tropical and Temperate Regions
			C. Whether Hot or Cold, All Deserts Are Dry
			D. Fire- and Drought-Adapted Plants Dominate Mediterranean Shrublands (Chaparral)
			E. Tundras Occupy High Latitudes and High Elevations
			F. The Polar Ice Caps House Cold-Adapted Species
		38.4 Freshwater Biomes Include Lakes, Ponds, and Streams
			A. Lakes and Ponds Contain Standing Water
			B. Streams Carry Running Water
		38.5 Oceans Make Up Earth’s Largest Ecosystem
			A. Land Meets Sea at the Coast
			B. The Open Ocean Remains Mysterious
		38.6 Investigating Life: Some Like It Hot
	39 Preserving Biodiversity
		39.1 Earth’s Biodiversity Is Dwindling
		39.2 Human Activities Destroy Habitats
		39.3 Pollution Degrades Habitats
			A. Water Pollution Threatens Aquatic Life
			B. Air Pollution Causes Many Types of Damage
			C. Global Climate Change Alters and Shifts Habitats
		39.4 Exotic Invaders and Overexploitation Devastate Many Species
			A. Invasive Species Displace Native Organisms
			B. Overexploitation Can Drive Species to Extinction
		39.5 Some Biodiversity May Be Recoverable
		39.6 Investigating Life: The Case of the Missing Frogs: Is Climate the Culprit?
Appendix A Answers to Multiple Choice Questions
Appendix B A Brief Guide to Statistical Significance
Appendix C Metric Units and Conversions
Appendix D Periodic Table of Elements
Appendix E Amino Acid Structures
Glossary
Credits
Index