UNIT 1

Unit Features

FRONTIERS IN SCIENCE Genes That Map the Body 2

TIMELINES IN SCIENCE The Story of Genetics 128

Cells and Heredity

All living things are made up of cells.

All cells need energy and materials for

life processes.

How do plants like these sunflowerschange energy from the Sun? page 38

The Cell 6

The cell is the basic unit of living things. 9CHAPTER INVESTIGATION Using a Microscope 16

Microscopes allow us to see inside the cell. 18MATH IN SCIENCE Using Scientific Notation 25

Different cells perform various functions. 26THINK SCIENCE Cells and Spacesuits 33

How Cells Function 38

Chemical reactions take place inside cells. 41SCIENCE ON THE JOB Natural Dyes and Cells 46

Cells capture and release energy. 47MATH IN SCIENCE Interpreting Graphs 55

Materials move across the cell’s membranes. 56CHAPTER INVESTIGATION Diffusion 64

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vi Life Science

GlucoseC6H12O6

�Oxygen

6O2

Carbondioxide

6CO2

Water6H2O ��

Glucose (C6H12O6)

Oxygen (6O2 )

Carbon dioxide (6CO2)

Water (6H2O)

What part of the diagram shows starting materials being changed?

Leaf cell (magnified 2200�)

Chloroplast

The starting materialsCarbon dioxide from the airand water from the soil enter the chloroplasts.

The process Inside thechloroplasts, chlorophyll captures energy from sunlight. This energy is usedto change starting materialsinto new products.

The products Glucose supplies energy and is asource of materials for theplant; most oxygen isreleased into the air.

321

Chloroplast

Photosynthesis

LightEnergy

LightEnergy

Chapter 2: How Cells Function 49 EA

Table of Contents vii

Cell Division 70

Cell division occurs in all organisms. 73CONNECTING SCIENCES Chemical Dyes Show Nerve Growth 79

Cell division is part of the cell cycle. 80CHAPTER INVESTIGATION Stages of the Cell Cycle 86

Both sexual and asexual reproduction involve cell division. 88

MATH IN SCIENCE Using Exponents 93

Patterns of Heredity 98

Living things inherit traits in patterns. 101CHAPTER INVESTIGATION Offspring Models 108

Patterns of heredity can be predicted. 110MATH IN SCIENCE Using Punnett Squares 116

Meiosis is a special form of cell division. 117THINK SCIENCE Are Traits Linked? 123

DNA and Modern Genetics 132

DNA and RNA are required to make proteins. 135CHAPTER INVESTIGATION Extract and Observe DNA 142

Changes in DNA can produce variation. 144MATH IN SCIENCE Finding Percent of a Whole 149

Modern genetics uses DNA technology. 150EXTREME SCIENCE Modern Genetics Meets the Dodo and the Solitare 155

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1Organisms grow, reproduce,

and maintain themselvesthrough cell division.

In sexual reproduction,genes are passed from parents to offspring in

predictable patterns.

DNA is a set of instructionsfor making cell parts.

Visual Highlights

Parts of a Eukaryotic Cell 22Levels of Organization 30Photosynthesis 49Cellular Respiration 51Cell Division 83Punnett Square and Probability 113Meiosis 121Translation 140

The History of Life on Earth 166

Earth has been home to living things for about 3.8 billion years. 169

MATH IN SCIENCE Using Proportions 176

Species change over time. 177CHAPTER INVESTIGATION Modeling Natural Selection 186

Many types of evidence support evolution. 188THINK SCIENCE How Did the Deep-Sea Angler Get Its Glow? 195

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FRONTIERS IN SCIENCE Life by Degrees 162

TIMELINES IN SCIENCE Life Unearthed 234

Life Over Time

Living things, like Earth itself, change over time.

viii Life Science

How do scientists learn about the history of life on Earth? page 166

UNIT 2

Table of Contents ix

Classification of Living Things 200

Scientists develop systems for classifying living things. 203MATH IN SCIENCE Writing Percents 210

Biologists use seven levels of classification. 211EXTREME SCIENCE The Undiscovered 219

Classification systems change as scientists learn more. 220CHAPTER INVESTIGATION Making a Field Guide 228

Population Dynamics 238

Populations have many characteristics. 241MATH IN SCIENCE Finding Averages 249

Populations respond to pressures. 250SCIENCE ON THE JOB Studying the Schools 257

Human populations have unique responses to change. 258CHAPTER INVESTIGATION Sustainable Resource

Management 266

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Scientists have developed a system for classifying

the great diversity of living things.

Populations are shaped by interactions

between organisms and the environment.

How many different typesof organisms do you seeand how would yougroup them? page 200

Visual Highlights

Natural Selection 183Biological Evidence for Evolution 191Classifying Organisms 215Dichotomous Key 217Six Kingdoms 222

Unit Features

FRONTIERS IN SCIENCE Chilling Changes 274

TIMELINES IN SCIENCE Discoveries in Biodiversity 350

Diversity of Living Things

Bacteria and protists have the characteristics

of living things, while viruses are not alive.

Multicellular organisms livein and get energy from avariety of environments.

How does an organismget energy and materialsfrom its environment?page 312

Single-Celled Organisms and Viruses 278

Single-celled organisms have all the characteristics of living things. 281

MATH IN SCIENCE Making a Line Graph 287

Bacteria are single-celled organisms without nuclei. 288CHAPTER INVESTIGATION Bacteria 294

Viruses are not alive but affect living things. 296EXTREME SCIENCE The Virus and the Tulip 301

Protists are a diverse group of organisms. 302

Introduction to Multicellular Organisms 312

Multicellular organisms meet their needs in different ways. 315

MATH IN SCIENCE Using Circle Graphs 322

Plants are producers. 323

Animals are consumers. 330SCIENCE ON THE JOB An Animal’s World 337

Most fungi are decomposers. 338CHAPTER INVESTIGATION What Do Yeast Cells

Use for Energy? 344

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UNIT 3

Table of Contents xi

Plants 354

Plants are adapted to living on land. 357

Most mosses and ferns live in moist environments. 364

Seeds and pollen are reproductive adaptations. 370CHAPTER INVESTIGATION Which Seeds Will Grow? 376EXTREME SCIENCE Seed Survivors 378

Many plants reproduce with flowers and fruit. 379MATH IN SCIENCE Using Grids to Estimate 387

Invertebrate Animals 392

Most animals are invertebrates. 395MATH IN SCIENCE Line Symmetry 399

Cnidarians and worms have different body plans. 400CHAPTER INVESTIGATION Worm Behavior 406

Most mollusks have shells and echinoderms have spiny skeletons. 408

THINK SCIENCE Eating Well 413

Arthropods have exoskeletons and joints. 414

Vertebrate Animals 426

Vertebrates are animals with endoskeletons. 429MATH IN SCIENCE Dividing by Decimals 435

Amphibians and reptiles are adapted for life on land. 436CONNECTING SCIENCES Sticky Feet 444

Birds meet their needs on land, in water, and in the air. 445CHAPTER INVESTIGATION Bird Beak Adaptations 452

Mammals live in many environments. 4544

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Plants are a diverse group of organisms that

live in many land environments.

Invertebrate animals have a variety of body plans and adaptations.

Vertebrate animals live in most of Earth’s

environments.

Visual Highlights

Making New Viruses 299Adaptations in Different Environments 319Inside a Leaf 361Life Cycle of a Pine Tree 373Life Cycle of a Cherry Tree 381Three Major Groups of Arthropods 416Wood Frog Life Cycle 438Adaptations for Flight 449

UNIT 4

Ecosystems and Biomes 470

Ecosystems support life. 473CHAPTER INVESTIGATION Soil Samples 478

Matter cycles through ecosystems. 480MATH IN SCIENCE Adding Integers 485

Energy flows through ecosystems. 486CONNECTING SCIENCES Biomagnification 493

Biomes contain many ecosystems. 4944

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FRONTIERS IN SCIENCE Ecosystems on Fire 466

TIMELINES IN SCIENCE Wilderness Conservation 538

Ecology

Matter and energy togethersupport life within

an environment.

xii Life Science

How many living and nonliving things can you identify in this photograph? page 470

Visual HighlightsEnergy Flows Through Ecosystems 491Aquatic Biomes 500Levels in the Environment 513Symbiotic Relationships 524Ecosystem Recovery 565

Chapter 15: Interactions Within Ecosystems 513

Organisms living in an African savannah illustrate the different levels of the environment.

Levels in the Environment

Biome The African savannah ispart of a grassland biome.

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EcosystemThe community of organisms, along withwater, soil, and otherabiotic factors, make upan ecosystem.

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CommunityPopulations of wildebeests, gazelles,lions, and grasses sharethe same living areasand resources. These andother populations form asavannah community.

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PopulationGazelles travel togetherin herds looking forareas to graze in. Thetotal number of gazellesin an ecosystem is calleda population of gazelles.

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OrganismThe gazelle lives in various grassland habitatsin eastern Africa and fillsa particular niche.

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Describe the gazelle’s place ineach level of the environment.

513

Table of Contents xiii

Interactions Within Ecosystems 506

Groups of living things interact within ecosystems. 509CHAPTER INVESTIGATION Estimating Populations 516

Organisms can interact in different ways. 518THINK SCIENCE Where Are the Salamanders? 526

Ecosystems are always changing. 527MATH IN SCIENCE Multiplying a Fraction by a Whole Number 533

Human Impact on Ecosystems 542

Human population growth presents challenges. 545SCIENCE ON THE JOB Ecology in Urban Planning 552

Human activities affect the environment. 553MATH IN SCIENCE Finding Volumes 561

People are working to protect ecosystems. 562CHAPTER INVESTIGATION Cleaning Oil Spills 570

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Humans and human population growth affect

the environment.

Living things within anecosystem interact

with each other and the environment.

How do living thingsinteract? page 506

Systems, Support, and Movement 582

The human body is complex. 585THINK SCIENCE What Does the Body Need to Survive? 589

The skeletal system provides support and protection. 590MATH IN SCIENCE Comparing Rates 597

The muscular system makes movement possible. 598CHAPTER INVESTIGATION A Closer Look at Muscles 604

Absorption, Digestion, and Exchange 610

The respiratory system gets oxygen and removes carbon dioxide. 613

SCIENCE ON THE JOB Breathing and Yoga 620

The digestive system breaks down food. 621MATH IN SCIENCE Choosing Units of Length 627

The urinary system removes waste materials. 628CHAPTER INVESTIGATION Modeling a Kidney 632

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FRONTIERS IN SCIENCE Surprising Senses 578

TIMELINES IN SCIENCE Seeing Inside the Body 670

The human body is made up of systems that work

together to perform neces-sary functions.

Systems in the body obtainand process materials and

remove waste.

xiv Life Science

What materials doesyour body need tofunction properly?page 610

Human BiologyUNIT 5

Table of Contents xv

Transport and Protection 638

The circulatory system transports materials. 641CHAPTER INVESTIGATION Heart Rate and Exercise 648

The immune system defends the body. 650MATH IN SCIENCE Making a Line Graph 658

The integumentary system shields the body. 659EXTREME SCIENCE Artificial Skin 665

Control and Reproduction 674

The nervous system responds and controls. 677CHAPTER INVESTIGATION Are You a Supertaster? 684

The endocrine system helps regulate body conditions. 686CONNECTING SCIENCES Heating and Cooling 693

The reproductive system allows the production of offspring. 694

MATH IN SCIENCE Solving Proportions 701

Growth, Development, and Health 706

The human body changes over time. 709SCIENCE ON THE JOB Aging the Face 715

Systems in the body function to maintain health. 716MATH IN SCIENCE Choosing a Data Display 723

Science helps people prevent and treat disease. 724CHAPTER INVESTIGATION Cleaning Your Hands 730

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Systems function to transport materials and

to defend and protect the body.

The nervous and endocrinesystems allow the body to

respond to internal andexternal conditions.

The body develops andmaintains itself over time.

Red blood cells travel through ablood vessel. How do you thinkblood carries materials aroundyour body? page 638

Visual Highlights

The Skeletal System 593Muscle Tissue 601Respiratory System 617Digestive System 625Circulatory System 644Growth of the Fetus 699Pathogens and Disease 727

The skull protectsthe brain.

Twelve pairs ofribs protect thelungs and heart.

The vertebrae ofthe spinal columnprotect the spinalcord and supportthe cranium andother bones.

The kneecap iscalled the patella.

There are 26bones in the ankleand the foot.

The lower leg bonesare called the tibiaand the fibula.

The upper leg bone, calledthe femur, is the longestbone in the body.

The many bones in thewrist and the hand allow itto perform a great varietyof activities.

The lowerarm bonesare the ulnaand radius.

The upper arm bone iscalled the humerus.

The shoulderblade is calledthe scapula.

The lower jaw is theonly bone in the skullthat can move.

Chapter 1: Systems, Support, and Movement 17

Axial skeleton

Appendicularskeleton

The word appendicular has the same root as the word append, which means toattach. How do you think this word applies to the appendicular skeleton?

The skeletal system interacts with other body systems toallow this soccer player to stand, run, and kick.

The Skeletal System

Math in Science

CELLS AND HEREDITYUsing Scientific Notation 25Interpreting Graphs 55Using Exponents 93Using Punnett Squares 116Finding Percent of a Whole 149

LIFE OVER TIMEUsing Proportions 176Writing Percents 210Finding Averages 249

DIVERSITY OF LIVING THINGSMaking a Line Graph 287Using Circle Graphs 322Using Grids to Estimate 387Line Symmetry 399Dividing by Decimals 435

ECOLOGYAdding Integers 485Multiplying a Fraction by a Whole Number 533Finding Volumes 561

HUMAN BIOLOGYComparing Rates 597Choosing Units of Length 627Making a Line Graph 658Solving Proportions 701Choosing a Data Display 723

Think Science

CELLS AND HEREDITYMaking Comparisons 33Determining Relevance 123

LIFE OVER TIMEEvaluating Hypotheses 195

DIVERSITY OF LIVING THINGSEvaluating Conclusions 413

ECOLOGYInferring 526

HUMAN BIOLOGYInferring 589

Connecting Sciences

CELLS AND HEREDITYLife Science and Physical Science 79

DIVERSITY OF LIVING THINGSLife Science and Physical Science 444

ECOLOGYLife Science and Physical Science 493

HUMAN BIOLOGYLife Science and Physical Science 693

Features

xvi Life Science

Table of Contents xvii

Science on the Job

CELLS AND HEREDITYNatural Dyes and Cells 46

LIFE OVER TIMEStudying the Schools 257

DIVERSITY OF LIVING THINGSAn Animal’s World 337

ECOLOGYEcology in Urban Planning 552

HUMAN BIOLOGYBreathing and Yoga 620Aging the Face 715

Extreme Science

CELLS AND HEREDITYModern Genetics Meets the Dodo and the Solitare 155

LIFE OVER TIMEThe Undiscovered 219

DIVERSITY OF LIVING THINGSThe Virus and the Tulip 301Seed Survivors 378

HUMAN BIOLOGYArtificial Skin 665

Frontiers in Science

CELLS AND HEREDITYGenes That Map the Body 2

LIFE OVER TIMELife by Degrees 162

DIVERSITY OF LIVING THINGSChilling Changes 274

ECOLOGYEcosystems on Fire 466

HUMAN BIOLOGYSurprising Senses 578

Timelines in Science

CELLS AND HEREDITYThe Story of Genetics 128

LIFE OVER TIMELife Unearthed 234

DIVERSITY OF LIVING THINGSDiscoveries in Biodiversity 350

ECOLOGYWilderness Conservation 538

HUMAN BIOLOGYSeeing Inside the Body 670

xviii Life Science

Simulations

CELLS AND HEREDITYVirtual Cell Tour 7Cells through Different Microscopes 19Stages of Cell Division 71Mendel’s Experiment 99Punnett Squares 111

LIFE OVER TIMEMatching Finch Beaks to Food 167Dichotomous Key 216

DIVERSITY OF LIVING THINGSSeed Dispersal 384

ECOLOGYCarrying Capacity 507

HUMAN BIOLOGYHuman Body Systems 583Assemble a Skeleton 592

Visualizations

CELLS AND HEREDITYPhotosynthesis 39Active Transport 60Mitosis 82Protein Synthesis 141

LIFE OVER TIMEFossil Formation 170Response to Environmental Change 248

DIVERSITY OF LIVING THINGSBinary Fission 284Bacteriophage Replication 298Plant Response to Stimuli 328Seeds Sprouting 355Cephalopod Movement 410Animal Distribution in North America 427How Fish Breathe 431

ECOLOGYNitrogen Cycle 484Human Population Growth 546

HUMAN BIOLOGYLung and Diaphragm Movement 611Peristalsis 622Heart Pumping Blood 639Skin Healing 663Fertilization and Implantation 696

of an Egg CellHuman Aging 707

Career CentersMolecular Biology 5

Paleontology 165

Zoology 277

Ecology 469

Neurobiology 581

Internet Resources @ ClassZone.com

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Table of Contents xix

Resource Centers

CELLS AND HEREDITYResources for the following topics may be found atClassZone.com: Cell Structures, UnicellularOrganisms, Macromolecules, Diffusion, NerveRegeneration, Cell Cycle, Asexual Reproduction,Sexual Reproduction, Meiosis, Genetics Research,Human Genome Project, DNA, Mutations, DNATechnology.

LIFE OVER TIMEResources for the following topics may be found atClassZone.com: Mass Extinctions, Natural Selection,Evidence Supporting Evolution, Linnaeus, Taxonomy,New Insect Species, Modern Classification, CurrentFossil and Living Fossil Finds, Population Dynamics,Human Population Growth, Introduced Species inthe United States.

DIVERSITY OF LIVING THINGSResources for the following topics may be found atClassZone.com: Single-Celled Organisms and theHuman Body, Bacteria, Viruses, Bee Dance, PlantAdaptations, Animal Adaptations, Fungi, BiodiversityDiscoveries and Research, Plant Systems, PlantEvolution, Seeds, Extreme Seeds, InvertebrateDiversity, Worms, Mollusks, Arthropods, Fish,Amphibians, Reptiles, Mammals.

ECOLOGYResources for the following topics may be found atClassZone.com: Prairie Ecosystems, Ecosystems,Cycles in Nature, Land and Aquatic Biomes,Symbiotic Relationships, Succession, ConservationEfforts, The Environment, Urban Expansion, NaturalResources, Ecosystem Recovery.

HUMAN BIOLOGYResources for the following topics may be found at ClassZone.com: Shackleton Expedition, SkeletalSystem, Muscles, Respiratory System, Urinary System,Circulatory System, Blood Types, Lymphatic System,Skin, Current Medical Imaging Techniques, Senses,Nervous System, Endocrine System, Human Health,Nutrition, Fighting Disease.

Math Tutorials

CELLS AND HEREDITYScientific Notation 25Interpreting Line Graphs 55Exponents 93Probability 116The Percent Equation 149

LIFE OVER TIMEWriting and Solving Proportions 176Percents and Fractions 210Finding the Mean 249

DIVERSITY OF LIVING THINGSInterpreting Line Graphs 287Interpreting Circle Graphs 322Perimeter and Area 387Line Symmetry 399Dividing by Decimals 435

ECOLOGYAdding Integers 485Multiplying Fractions and Whole Numbers 533Finding the Volume of a Rectangular Prism 561

HUMAN BIOLOGYUnit Rates 597Measuring Length 627Making Line Graphs 658Solving Proportions 701Choosing a Data Display 723

NSTA SciLinksCodes for use with the NSTA SciLinks site maybe found on every chapter opener.

Content ReviewThere is a content review for every chapter atClassZone.com

Test PracticeThere is a standardized test practice for everychapter at ClassZone.com

Cells and HereditySeeing and Understanding; Bits and Pieces 7Leaves Underwater; Just a Spoonful

of Sugar 39Dividing to Multiply; Division Math 71How Are Traits Distributed? Combinations 99What Is the Pattern? What Vegetable

Is That? 99

Life Over TimeWhat Can Rocks Show About Earth’s History?

Which One of These Things Is Not Like the Others? 167

How Are Fingerprints Different? How Would You Sort Pennies? 201

How Does Population Grow? How Do Populations Differ? 239

Diversity of Living ThingsWhere Can You Find Microscopic Life?

How Quickly Do Bacteria Multiply? 279Where Does It Come From? How Can a

Multicellular Organism Reproduce on Its Own? 313

How Are Plants Alike, How Are They Different? How Are Seeds Dispersed? 355

Worm-Watching; Insects and You 393What Animals Live Near You? How Is a

Bird like a Frog? 427

EcologyHow Do Plants React to Sunlight?

What Is Soil? 471How Do Living Things Interact Where You

Live? How Many Roles Can a Living ThingHave in an Ecosystem? 507

How Many is Six Billion? How Easily DoesPolluted Water Move Through Plants? 543

Human BiologyHow Many Bones Are in Your Hand?

How Does It Move? 583Mirror, Mirror; Water Everywhere 611Blood Pressure; Wet Fingers 639Color Confusion; Eggs 675How Much Do You Exercise? How Safe

Is Your Food? 707

Explore the Big IdeaExplore the Big IdeaChapter Opening Inquiry

Each chapter opens with hands-on explorations that introduce the chapter’s Big Idea.

xx Life Science

Cells and HeredityUsing a Microscope 16Diffusion 64Stages of the Cell Cycle 86Offspring Models 108Extract and Observe DNA 142

Life Over TimeModeling Natural Selection 186Making a Field Guide 228Sustainable Resource Management 266

Diversity of Living ThingsBacteria 294What Do Yeast Cells Use for Energy? 344Which Seeds Will Grow? 376Worm Behavior 406Bird Beak Adaptations 452

EcologySoil Samples 478Estimating Populations 516Cleaning Oil Spills Design Your Own 570

Human BiologyA Closer Look at Muscles 604Modeling a Kidney 632Heart Rate and Exercise 648Are You a Supertaster? 684Cleaning Your Hands 730

name of lab, skill?, mod-ule and page number

Chapter InvestigationsChapter InvestigationsFull-Period Labs

The Chapter Investigations are in-depth labs thatlet you form and test a hypothesis, build a model,or sometimes design your own investigation.

Table of Contents xxi

Cells and HeredityActivity and Life 9Specialization 26Food Molecules 41Diffusion 56Cell Division 73Probability 110Meiosis 117Templates 135Codes 144

Life Over TimeFossils 169Evidence 188Classification 211Population Density 250Population Change 258

Diversity of Living ThingsOrganisms 281Viruses 296Stored Energy 323Mushrooms 338Leaf Characteristics 357Moss Plants 364Fruit 379Worm Movement 400Arthropods 414Streamlined Shapes 429Moving on Land 436Feathers 445

EcologyYour Environment 473The Water Cycle 480Energy 486Counting Animals 509Population Growth 527Sharing Resources 545Environmental Impacts 562

Human BiologyLevers 590Muscles 598Breathing 613Digestion 621Waste Removal 628The Circulatory System 641Membranes 650The Skin 659Smell 677Reproduction 694Growth 709The Immune System 724

ExploreExploreIntroductory Inquiry Activities

Most sections begin with a simple activity that lets youexplore the Key Concept before you read the section.

xxii Life Science

InvestigateInvestigateSkill Labs

Each Investigate activity gives you a chance to practice a specificscience skill related to the content that you’re studying.

Cells and HeredityPlant and Animal Cells Observing 21Cell Models Making models 31Oil and Water Observing 44Fermentation Observing 53Cells Making models 62Chromosomes Making models 76Cell Division Making models 84Asexual Reproduction Drawing conclusions 91Multiple Probabilities Analyzing data 114Fertilization Design Your Own 119Neutral Mutations Making models 146

Life Over TimeFossil Records Analyzing 171Genes Sequencing 193Classifying Leaves Classifying 206Binomial Nomenclature Classifying 212Limiting Factors Design Your Own 254Population Graphing data 262

Diversity of Living ThingsMicroorganisms Observing 285Viruses Analyzing 297Protists Observing 303Specialization Making models 316What Plants Need to Grow Design Your Own 324Owl Pellets Inferring 332Capturing the Sun’s Energy Measuring 366Pinecones Observing 374Flower Parts Observing 383Invertebrates Observing 396Mollusks and Echinoderms Observing 410Insect Metamorphosis Observing 418Eggs Observing 442How Body Fat Insulates Making models 456

EcologyCarbon Observing 483Decomposers Observing 489Climate Graphing Data 499Species Interactions Analyzing Data 521Limiting Factors Design Your Own 529Resources Interpreting 548Particles in the Air Observing 555

Human BiologySystems Predicting 586Movable Joints Observing 595Lungs Making models 615Chemical Digestion Making models 623Antibodies Making models 655Skin Protection Observing 661Response to Exercise Observing 690Life Expectancy Graphing 713Food Labels Analyzing 719

Table of Contents xxiii