Ch 4 a closer look hormones and glucose levels

Engaged with you. www.cengage.com

Source Code: 14M-AA0105

Tap into engagement MindTap empowers you to produce your best work—consistently.

MindTap is designed to help you master the material. Interactive videos, animations, and activities create a learning path designed by your instructor to guide you through the course and focus on what’s important.

Tap into more info at: www.cengage.com/mindtap

“MindTap was very useful – it was easy to follow and everything was right there.” — Student, San Jose State University

“I’m definitely more engaged because of MindTap.” — Student, University of Central Florida

“MindTap puts practice questions in a format that works well for me.” — Student, Franciscan University of Steubenville

MindTap helps you stay organized and efficient by giving you the study tools to master the material.

MindTap empowers and motivates

with information that shows where you stand at all times—both individually and compared to the highest performers in class.

MindTap delivers real-world activities and assignments

that will help you in your academic life as well as your career.

Flashcards

readspeaker

progress app

MyNotes & highlights

selF QuizziNg & practice

Copyright 2016 Cengage Learning. All Rights Reserved. May not be copied, scanned, or duplicated, in whole or in part. Due to electronic rights, some third party content may be suppressed from the eBook and/or eChapter(s).

Editorial review has deemed that any suppressed content does not materially affect the overall learning experience. Cengage Learning reserves the right to remove additional content at any time if subsequent rights restrictions require it.

Today & Tomorrow

5e

Cecie Starr | Christine A. Evers | Lisa Starr

Australia • Brazil • Mexico • Singapore • United Kingdom • United States

Copyright 2016 Cengage Learning. All Rights Reserved. May not be copied, scanned, or duplicated, in whole or in part. Due to electronic rights, some third party content may be suppressed from the eBook and/or eChapter(s).

Editorial review has deemed that any suppressed content does not materially affect the overall learning experience. Cengage Learning reserves the right to remove additional content at any time if subsequent rights restrictions require it.

This is an electronic version of the print textbook. Due to electronic rights restrictions, some third party content may be suppressed. Editorial review has deemed that any suppressed content does not materially affect the overall learning experience. The publisher reserves the right to remove content from this title at any time if subsequent rights restrictions require it. For valuable information on pricing, previous editions, changes to current editions, and alternate formats, please visit www.cengage.com/highered to search by ISBN#, author, title, or keyword for materials in your areas of interest.

Important Notice: Media content referenced within the product description or the product text may not be available in the eBook version.

Copyright 2016 Cengage Learning. All Rights Reserved. May not be copied, scanned, or duplicated, in whole or in part. Due to electronic rights, some third party content may be suppressed from the eBook and/or eChapter(s).

Editorial review has deemed that any suppressed content does not materially affect the overall learning experience. Cengage Learning reserves the right to remove additional content at any time if subsequent rights restrictions require it.

© 2016, 2013 Cengage Learning

ALL RIGHTS RESERVED. No part of this work covered by the copyright herein may be reproduced, transmitted, stored, or used in any form or by any means graphic, electronic, or mechanical, including but not limited to photocopying, recording, scanning, digitizing, taping, Web distribution, information networks, or information storage and retrieval systems, except as permitted under Section 107 or 108 of the 1976 United States Copyright Act, without the prior written permission of the publisher.

Library of Congress Control Number: 2014958336

Bound Edition: ISBN: 978-1-305-11735-8

Loose-leaf Edition: ISBN: 978-1-305-62939-4

Cengage Learning 20 Channel Center Street Boston, MA 02210 USA

Cengage Learning is a leading provider of customized learning solutions with office locations around the globe, including Singapore, the United Kingdom, Australia, Mexico, Brazil, and Japan. Locate your local office at www.cengage.com/global.

Cengage Learning products are represented in Canada by Nelson Education, Ltd.

To learn more about Cengage Learning Solutions, visit www.cengage.com.

Purchase any of our products at your local college store or at our preferred online store www.cengagebrain.com.

Biology Today and Tomorrow, Fifth Edition Cecie Starr, Christine A. Evers, Lisa Starr

Product Director: Mary Finch

Senior Product Team Manager: Yolanda Cossio

Managing Content Developer: Trudy Brown

Product Assistant: Victor Luu

Content Developer: Lauren Oliveira

Associate Content Developers: Kellie N. Petruzzelli, Casey J. Lozier

Senior Market Development Manager: Tom Ziolkowski

IP Analyst: Christine M. Myaskovsky

IP Project Manager: John N. Sarantakis

Content Project Manager: Hal Humphrey

Senior Art Director: Bethany Casey

Manufacturing Planner: Karen Hunt

Production Service: Grace Davidson & Associates

Photo Researchers: Cheryl DuBois and Megan Cooper, Lumina Datamatics

Text Researcher: Kavitha Balasundaram, Lumina Datamatics

Copy Editor: Anita Wagner Hueftle

Illustrators: Lisa Starr, ScEYEnce Studios, Precision Graphics, Gary Head

Interior Designer: Michael Stratton, Stratton Design

Cover Designer: Michael Stratton, Stratton Design

Cover Image: © Shutterstock, Inc./Felix Rohan

Compositor: Lachina Publishing Services

For product information and technology assistance, contact us at Cengage Learning Customer & Sales Support, 1-800-354-9706.

For permission to use material from this text or product, submit all requests online at www.cengage.com/permissions.

Further permissions questions can be e-mailed to permissionrequest@cengage.com.

Printed in the United States of America Print Number: 01 Print Year: 2015

WCN: 02-200-202

Copyright 2016 Cengage Learning. All Rights Reserved. May not be copied, scanned, or duplicated, in whole or in part. Due to electronic rights, some third party content may be suppressed from the eBook and/or eChapter(s).

Editorial review has deemed that any suppressed content does not materially affect the overall learning experience. Cengage Learning reserves the right to remove additional content at any time if subsequent rights restrictions require it.

1 Invitation to Biology

Unit 1 How Cells work

2 Molecules of Life

3 Cell Structure

4 Energy and Metabolism

5 Capturing and Releasing Energy

Unit 2 GenetiCs

6 DNA Structure and Function

7 Gene Expression and Control

8 How Cells Reproduce

9 Patterns of Inheritance

10 Biotechnology

Unit 3 evolUtion and diversity

11 Evidence of Evolution

12 Processes of Evolution

13 Early Life Forms and the Viruses

14 Plants and Fungi

15 Animal Evolution

Unit 4 eColoGy

16 Population Ecology

17 Communities and Ecosystems

18 The Biosphere and Human Effects

Unit 5 How animals work

19 Animal Tissues and Organs

20 How Animals Move

21 Circulation and Respiration

22 Immunity

23 Digestion and Excretion

24 Neural Control and the Senses

25 Endocrine Control

26 Reproduction and Development

Unit 6 How Plants work

27 Plant Form and Function

28 Plant Reproduction and Development

B r

IE F

C o

N T

E N

T S

BC

Copyright 2016 Cengage Learning. All Rights Reserved. May not be copied, scanned, or duplicated, in whole or in part. Due to electronic rights, some third party content may be suppressed from the eBook and/or eChapter(s).

Editorial review has deemed that any suppressed content does not materially affect the overall learning experience. Cengage Learning reserves the right to remove additional content at any time if subsequent rights restrictions require it.

1 Invitation to Biology 1.1 the secret life of earth 4

1.2 life is more than the sum of its Parts 4

1.3 How living things are alike 6

Organisms Require Energy and Nutrients 6

Organisms Sense and Respond to Change 6

Organisms Grow and Reproduce 6

1.4 How living things differ 8

What Is a Species? 8

A Rose by Any Other Name 10

1.5 the science of nature 11

Thinking About Thinking 12

How Science Works 12

Examples of Experiments in Biology 13

1.6 the nature of science 16

Bias in Interpreting Experimental Results 16

Sampling Error 17

Scientific Theories 18

The Scope of Science 19

UNIT 1 HOw CELLS wORk

2 Molecules of Life 2.1 Fear of Frying 24

2.2 start with atoms 25

Why Electrons Matter 26

2.3 From atoms to molecules 28

Ionic Bonds 28

Covalent Bonds 28

2.4 Hydrogen Bonds and water 29

Water Is an Excellent Solvent 30

Water Has Cohesion 31

Water Stabilizes Temperature 31

2.5 acids and Bases 32

2.6 organic molecules 33

What Cells Do to Organic Compounds 33

2.7 Carbohydrates 34

2.8 lipids 36

Fats 36

Phospholipids 36

Waxes 37

Steroids 37

2.9 Proteins 38

The Importance of Protein Structure 39

2.10 nucleic acids 41

3 Cell Structure 3.1 Food for thought 46

3.2 what, exactly, is a Cell? 46

The Cell Theory 46

Components of All Cells 47

Constraints on Cell Size 47

How Do We See Cells? 48

3.3 Cell membrane structure 50

Membrane Proteins 51

3.4 introducing Prokaryotic Cells 52

Biofilms 53

3.5 introducing eukaryotic Cells 54

The Nucleus 54

The Endomembrane System 54

Mitochondria 55

Chloroplasts 56

The Cytoskeleton 56

Extracellular Matrix 58

Cell Junctions 58

3.6 the nature of life 59

C C

o N

T E

N T

S

Copyright 2016 Cengage Learning. All Rights Reserved. May not be copied, scanned, or duplicated, in whole or in part. Due to electronic rights, some third party content may be suppressed from the eBook and/or eChapter(s).

Editorial review has deemed that any suppressed content does not materially affect the overall learning experience. Cengage Learning reserves the right to remove additional content at any time if subsequent rights restrictions require it.

4 Energy and Metabolism 4.1 a toast to alcohol dehydrogenase 64

4.2 life runs on energy 65

4.3 energy in the molecules of life 66

Why Earth Does Not Go Up in Flames 67

Energy In, Energy Out 68

4.4 How enzymes work 68

The Need for Speed 68

Factors That Influence Enzyme Activity 69

Cofactors 70

Metabolic Pathways 71

Controlling Metabolism 71

Electron Transfers 72

4.5 diffusion and membranes 73

Semipermeable Membranes 73

4.6 membrane transport mechanisms 75

Passive Transport 75

Active Transport 76

Membrane Trafficking 76

5 Capturing and Releasing Energy

5.1 a Burning Concern 82

5.2 to Catch a rainbow 83

Storing Energy in Sugars 84

5.3 light-dependent reactions 85

5.4 light-independent reactions 87

Alternative Carbon-Fixing Pathways 87

5.5 a Global Connection 89

Aerobic Respiration in Mitochondria 89

5.6 Fermentation 92

5.7 Food as a source of energy 94

Complex Carbohydrates 94

Fats 94

Proteins 95

UNIT 2 GENETICS

6 DNA Structure and Function 6.1 Cloning 100

6.2 Fame, Glory, and dna structure 102

Discovery of DNA’s Function 102

Discovery of DNA’s Structure 104

DNA Sequence 105

6.3 dna in Chromosomes 106

6.4 dna replication and repair 108

How Mutations Arise 108

7 Gene Expression and Control 7.1 ricin, riP 114

7.2 Gene expression 115

7.3 transcription: dna to rna 116

RNA Modifications 117

7.4 the Genetic Code 118

7.5 translation: rna to Protein 119

7.6 Products of mutated Genes 122

7.7 Control of Gene expression 124

Master Genes 124

Sex Chromosome Genes 125

Lactose Tolerance 125

DNA Methylation 126

CONTENTS v

Copyright 2016 Cengage Learning. All Rights Reserved. May not be copied, scanned, or duplicated, in whole or in part. Due to electronic rights, some third party content may be suppressed from the eBook and/or eChapter(s).

Editorial review has deemed that any suppressed content does not materially affect the overall learning experience. Cengage Learning reserves the right to remove additional content at any time if subsequent rights restrictions require it.

8 How Cells Reproduce 8.1 Henrietta’s immortal Cells 132

8.2 multiplication by division 133

Cytoplasmic Division 136

8.3 mitosis and Cancer 137

Cell Division Gone Wrong 137

Cancer 138

Telomeres 139

8.4 sex and alleles 140

On the Advantages of Sex 140

8.5 meiosis in sexual reproduction 142

How Meiosis Mixes Alleles 144

From Gametes to Offspring 144

9 Patterns of Inheritance 9.1 menacing mucus 150

9.2 tracking traits 151

Mendel’s Experiments 151

Inheritance in Modern Terms 151

9.3 mendelian inheritance Patterns 152

Monohybrid Crosses 153

Dihybrid Crosses 154

9.4 Beyond simple dominance 155

Incomplete Dominance 155

Codominance 155

Pleiotropy and Epistasis 156

9.5 Complex variation in traits 158

Continuous Variation 159

9.6 Human Genetic analysis 160

Types of Genetic Variation 160

9.7 Human Genetic disorders 161

The Autosomal Dominant Pattern 162

The Autosomal Recessive Pattern 163

The X-Linked Recessive Pattern 164

9.8 Chromosome number Changes 165

Autosomal Change and Down Syndrome 166

Change in the Sex Chromosome Number 166

9.9 Genetic screening 168

10 Biotechnology 10.1 Personal Genetic testing 174

10.2 Finding needles in Haystacks 175

Cutting and Pasting DNA 175

DNA Libraries 176

PCR 177

10.3 studying dna 178

Sequencing the Human Genome 178

Genomics 179

DNA Profiling 179

10.4 Genetic engineering 181

Genetically Modified Microorganisms 181

Designer Plants 181

Biotech Barnyards 182

10.5 modifying Humans 184

Gene Therapy 184

Eugenics 185

UNIT 3 EVOLUTION AND DIVERSITy

11 Evidence of Evolution 11.1 reflections of a distant Past 190

11.2 Confusing discoveries 191

11.3 a Flurry of new ideas 192

Squeezing New Evidence Into Old Beliefs 192

Darwin and the HMS Beagle 193

A Key Insight—Variation in Traits 194

Great Minds Think Alike 195

11.4 Fossil evidence 196

The Fossil Record 196

vi CONTENTS

Copyright 2016 Cengage Learning. All Rights Reserved. May not be copied, scanned, or duplicated, in whole or in part. Due to electronic rights, some third party content may be suppressed from the eBook and/or eChapter(s).

Editorial review has deemed that any suppressed content does not materially affect the overall learning experience. Cengage Learning reserves the right to remove additional content at any time if subsequent rights restrictions require it.

CONTENTS vii

Radiometric Dating 197

Missing Links 199

11.5 drifting Continents 200

Putting Time Into Perspective 201

11.6 evidence in Form 204

Morphological Divergence 204

Morphological Convergence 205

11.7 evidence in Function 206

Patterns in Animal Development 207

12 Processes of Evolution 12.1 superbug Farms 212

12.2 alleles in Populations 213

An Evolutionary View of Mutations 213

Allele Frequency 214

12.3 modes of natural selection 215

Directional Selection 215

Stabilizing Selection 217

Disruptive Selection 217

12.4 natural selection and diversity 218

Survival of the Sexiest 218

Maintaining Multiple Alleles 219

12.5 Genetic drift and Gene Flow 220

Bottlenecks and the Founder Effect 220

Gene Flow 221

12.6 speciation 222

Reproductive Isolation 222

Allopatric Speciation 224

Sympatric Speciation 224

12.7 macroevolution 226

Evolutionary Theory 228

12.8 Phylogeny 229

Applications of Phylogeny 230

13 Early Life Forms and the Viruses 13.1 the Human micobiome 236

13.2 on the road to life 237

Conditions on the Early Earth 237

Origin of the Building Blocks of Life 237

Origin of Metabolism 238

Origin of Genetic Material 238

Origin of Cell Membranes 239

13.3 origin of the three domains 240

Reign of the Prokaryotes 240

Origin of Eukaryotes 241

13.4 viruses 242

Viral Structure and Replication 242

Bacteriophages 242

Plant Viruses 243

Viruses and Human Health 243

HIV—The AIDS Virus 244

Ebola 245

New Flus 245

13.5 Bacteria and archaea 246

Structure and Function 246

Reproduction and Gene Transfers 246

Metabolic Diversity 247

Domain Archaea 248

Domain Bacteria 248

13.6 Protists 250

Flagellated Protozoans 250

Foraminifera 251

Ciliates 251

Dinoflagellates 252

Apicomplexans 252

Water Molds, Diatoms, and Brown Algae 254

Red Algae 255

Green Algae 255

Amoebas and Slime Molds 256

Choanoflagellates 257

14 Plants and Fungi 14.1 Fungal threats to Crops 262

14.2 Plant traits and evolution 263

Life Cycle 263

Structural Adaptations to Life on Land 264

Reproduction and Dispersal 264

14.3 nonvascular Plants 265

Mosses 265

Liverworts and Hornworts 266

14.4 seedless vascular Plants 266

Ferns 266

Horsetails and Club Mosses 267

14.5 rise of the seed Plants 269

Copyright 2016 Cengage Learning. All Rights Reserved. May not be copied, scanned, or duplicated, in whole or in part. Due to electronic rights, some third party content may be suppressed from the eBook and/or eChapter(s).

Editorial review has deemed that any suppressed content does not materially affect the overall learning experience. Cengage Learning reserves the right to remove additional content at any time if subsequent rights restrictions require it.

14.6 Gymnosperms 270

Conifers 270

Cycads and Ginkgos 271

Gnetophytes 271

14.7 angiosperms—Flowering Plants 272

Floral Structure and Function 272

A Flowering Plant Life Cycle 273

Keys to Angiosperm Diversity 273

Major Groups 273

Ecology and Human Uses of Angiosperms 274

14.8 Fungal traits and diversity 274

Yeasts, Molds, Mildews, and Mushrooms 274

Lineages and Life Cycles 275

14.9 ecological roles of Fungi 277

Decomposers 277

Parasites 277

Fungal Partnerships 278

Human Uses of Fungi 279

15 Animal Evolution 15.1 medicines From the sea 284

15.2 origins and diversification 285

Animal Origins 285

Evidence of Early Animals 285

Major Groups and Evolutionary Trends 286

15.3 invertebrate diversity 288

Sponges 288

Cnidarians 288

Flatworms 289

Annelids 290

Mollusks 290

Roundworms 291

Arthropods 292

Echinoderms 296

15.4 introducing the Chordates 297

Chordate Traits 297

Invertebrate Chordates 297

Vertebrate Traits and Trends 298

15.5 Fishes and amphibians 299

Jawless Fishes 299

Jawed Fishes 299

Early Tetrapods 300

Modern Amphibians 301

15.6 escape From water—amniotes 302

Amniote Innovations 302

Nonbird Reptiles 302

Birds 303

Mammals 303

15.7 Human evolution 305

Primate Traits 305

Primate Origins and Diversification 305

Australopiths 306

Early Humans 307

Homo Sapiens 308

Neanderthals and Denisovans 308

UNIT 4 ECOLOGy

16 Population Ecology 16.1 a Honkin’ mess 314

16.2 Characteristics of Populations 315

Demographic Traits 315

Collecting Demographic Data 316

16.3 Population Growth 317

Exponential Growth 317

Carrying Capacity and Logistic Growth 318