Genetics : a conceptual approach

863 Pages·2014·128.18 MB·English

by  Benjamin A. Pierce

A Conceptual Approach
FIFTH EDITION
Contents in Brief
1. Introduction to Genetics 1
2 . Chromosomes and Cellular Reproduction 17
3. Basic Principles of Hered ity 45
4 . Sex Determination and Sex-Linked Characteristics 77
5. Extensions and Modifications of Basic Principles 103
6 . Ped ig ree Analysis, Applications, and Genetic Testing 139
7. Linkage, Recombination, and Eukaryotic Gene Mapping 165
8 . Chromosome Variation 209
9 . Bacterial and Viral Genetic Systems 241
10. DNA: The Chemical Nature of the Gene 277
11. Chromosome Structure and Organelle DNA 299
12. DNA Replication and Recombination 325
13. Transcription 357
14. RNA Molecules and RNA Processing 383
15. The Genetic Code and Translation 411
16. Control of Gene Expression in Bacteria 443
17. Control of Gene Expression in Eukaryotes 473
18. Gene Mutations and DNA Repair 493
19. Molecular Genetic Analysis and Biotechnology 535
20. Genomics and Proteomics 579
21. Epigenetics 613
22. Developmental Genetics and lmmunogenetics 633
23. Cancer Genetics 661
24. Quantitative Genetics 683
25. Population Genetics 715
26. Evolutionary Genetics 743
Reference Guide to Model Genetic Organisms A1
Contents
Letter fron1 the Author XV CONNECTING CONCEPTS Mitosi.s and M eiosis Compared 33
Preface xvi
The Separation ofS ister Chromatids and
Chapter 1 Introduction to Genetics i Hon1ologous Chron1oson1es 3 3
Meiosis in t he Life Cycles of Animals and
Albinism in the Hopis 1 Plants 35
1.1 Genetics ls lmportantto Us Individually,
to Society, and to the Study of Biology 2 Chapter 3 Basic Principles of
The Role of Genetics in Biology 4 Heredity 45
C'renetic Diversity and Evolution 4 The Genetics of Red Hair 45
Divisions of Genetics 5
Model Genetk Organisms 5 3. 1 Gregor Mendel Discovered the Basic
Principles of Heredity 46
1.2 Humans Have Been Using Genetics for
Mendeli;Su ccess 47
Thousands of Years 7
Genetic Terminology 48
The Early Use and Understanding of Heredity 7
The Rise ofthe ScienceofGenetks 9 3.2 Monohybrid Crosses Reveal the Principle
The Future of C'.enetics 10 of Segregation and the Concept of
Dominance 49
1.3 A Few Fundamental Concepts Are Important
What Monohybrid Crosses Reveal 5 0
for the Start of Our Journey into Genetics 11
CONNECTING CONCEPTS Relating Geneti c Crosse s to
Meiosis 52
Chapter 2 Chromosomes and Cellular
Reproduction 11 The Molecular Nature of Alleles 5 3
The Blind Men's Riddle 17 Predicting the Outcon1es of Genetic Cros..'ies 53
The Testcross 57
2.1 Prokaryotic and Eukaryotic Cells Differ in a
Genetk Symbols 58
Number of Genetic Characteristics 18
2.2 Cell Reproduction Requires the Copying of CONNECTING CONCEPTS Ratios in Simple Crosses 58
the Genetic Material, Separation of the
Copies, and Cell Division 20 3.3 Dihybrid Crosses Reveal the Prindple of
Independent Assortment 5 9
Prokaryotic Cell Reproduction 20
Eukaryotk Cell Reproduction 20 Di hybrid Crosses 59
The Cell Cycle and Mitosis 23 The Principle of Ind ependent Assortment 59
C'.enetic Comequences of the CeU Cycle 26 Relating the Principle of Ind epend ent Assortment to
Meiosis 60
CONNECTING CONCEPTS Counting Chromosomes and DNA Applying Probability and the Branch Diagram to
M olecules 27
Di hybrid Crosses 61
The Di hybrid Testcross 62
2.3 Sexual Reproduction Produces Genetic
Variation Through the Process of Meiosis 27 3.4 Observed Ratios of Progeny May Deviate
from Expected Ratios by Chance 64
Meiosis 28
Sources of Genetic Variation in Meiosis 31 The Goodness-of-Fit Chi-Squ are Test 6 4
v
Contents vii
Chapter 7 Linkage, Recombination, Chapter 8 Chromosome
and Eukaryotic Gene Mapping 165 Variation 209
Linked Genes and Bald Heads 165 Building a Better Banana 209
7.1 linked Genes Do Not Assort 8.1 Chromosome Mutations Include
Independently 166 Rearrangements. Aneuploids, and
Polyploids 210
7.2 linked Genes Segregate Together and
Chromosome Morphology 210
Crossing OVer Produces Recombination
Types of Chron1oson1e
Between Them 167
Mutations 211
Notation for Crosses with Linkage 168
8.2 Chromosome Rearrangements Alter
Complete Linkage Compared with Independent
Chromosome Structure 212
A&<ortment 168
Duplications 212
Crossing Over with Linked Gen es 170
Deletions 214
Calculating Recombination Frequency 171
Inversions 216
Coupling and Repulsion 172
Translocations 219
CONNECTING CONCEPTS Relating Independent Assortment Fragile Sites 221
linkage, and Crossing over 173 Copy-Number Variations 222
Evidence for the Physical Basi.s of 8.3 Aneuploidy ls an Increase or Decrease in the
Number of Individual Chromosomes 222
Recombination 174
Predicting th e Outcomes of Crosses with Linked Types of Aneuploidy 222
C.enes 175 Effectsof Aneuploidy 223
Aneuploidy in Humans 224
Testing for In depend ent A&<ortment 176
Uni parental Di<nmy 22 7
Crene lvfapping \\'ith Recon1bination
Mosaicism 228
Frequencies 178
Omstructing a C.enetic Map with the Use of 8.4 Polyploidy Is the Presence of More than Two
T\.;o ~Point Testcros.ses 179 Sets of Chromosomes 228
Autopolyploidy 228
7 3 A Three-Point Testcross Can Be Used to Map
Allopolyploidy 229
Three Linked Genes 180
The Significanceof Polyploidy 232
Constructing a Genetic. !Ylap \.;ith the Three .. Point
Testcross 181
Chapter 9 Bacterial and Viral
CONNECTING CONCEPTS Stepping Through the Three-Point Genetic Systems 241
Cross 186
Life in a Bacterial World 241
Effect of Multiple Cxossovers 188
9.1 Genetic Analysis of Bacteria Requires Special
Mapping Human Genes 189
Methods 242
lv!apping with Molecular Markers 190
Bacterial Diversity 242
C',enes Can Be Located \\Tith Genon1e,~e
Techniques for t he Study of Bacteria 243
Assodatio nStud ies 191 The Bacterial Genome 244
Plasmids 245
7 .4 Physical-Mapping Methods Are Used to
Determine the Physical Positions of Genes on
9.2 Bacteria Exchange Genes Through
Particular Chromosomes 192
Conjugation, Transformation, and
Transduction 247
Somatic· Cell Hybridization 192
Conjugation 247
Deletions Mapping 194
Natural Gene Transfer and Antibiotic
Physical Chromosome Mapping Through
Resistance 254
Molecular Analysis 195
Transforn1ation in Bacteria 25 4
7.5 Recombination Rates Exhibit Extensive Bacterlal Genon1e Sequences 256
Variation 195 Horizontal Gene Transler 256
v
viii Contents
9.3 Viruses Are Simple Replicating Systems 11.2 Eukaryotic Chromosomes Possess
Amenable to Genetic Analysis 257 Centromeres and Telomeres 306
Tech niques for the Study of Bacterioph age.< 25 7 Centmn1ere Structure 306
Transduction: Using Phages to lv!ap Bacterial TelomereStructure 307
Genes 258
11.3 Eukaryotic DNA Contains Several Classes of
Sequence Variation 308
CONNECTING CONCEPTS Three Methods for Mapping
The Denaturation and Renaturation
Bacterial Gent?S 261
of DNA 3 08
Gene Mapping in Phages 261 Types of DNA Sequences in Eukaryotes 308
Fine-Structure Analysis of Bacteriophage
11.4 Organelle DNA Has Unique
Genes 263
Characteristics 309
RNA Viruses 265
Mitochond rion and Chloroplast Structur e 309
Human Immunodeficiency Virus and AIDS 267
The Endosymbiotic Theory 310
l nfluenz.a 268
Uniparental In heritance of Organelle· Encoded
T raits 31 1
Chapter 10 DNA: The Chemical
The Mitochon drial Genome 314
Nature of the Gene 277 The Evolution oflvlitoch ondrial DNA 316
Damage to Mitochondrial DNA ls Associated with
Arctic Treks and Ancient DNA 277
Aging 316
10.1 Genetic Material Possesses Several Key The Chloropla.st Genome 317
Characteristics 278
Through Evolutionary T in1e. Genetk Jnf0rn1ation
10.2 All Genetic Information Is Encoded in the Has rvtoved Bet\'leen Nuclear, lvlitochondr ial, and
Structure of DNA or RNA 278 Chloroplast Genome.< 318
EarlyStud iesof DNA 278
DNA As the Source of Genetic InlOrmation 280 Chapter 12 DNA Replication and
\iVatson and Crkk's Di'ic.overy of the Three. .
Recombination 325
Dimensional Structure of DNA 283
Topoisomerase, Replication, and
RNA As Genetk Material 285
Cancer 325
10.3 DNA Consists of Two Complementary and
Antiparallel Nucleotide Strands That Form a 12.1 Genetk Information Must Be Accurately
Double Helix 286 Copied Every Time a Cell Divides 326
The Primary Structure of DN A 286 12.2 All DNA Replkation Takes Place in a
Secondary Structures of DNA 288 Semiconservative Manner 326
Meselson and Stahl&E 'l'eriment 327
CONNECTING CONCEPTS Genetic Implications of DNA
Mode.of Replb tion 329
St ructure 290
Requirements of Replication 332
Direction of Replication 332
10.4 Special Structures Can Form in DNA and
RNA 291
CONNECTING CONCEPTS The Direction of Synthesis in
Di fferent Models of Replicati on 334
Chapter 11 Chromosome Structure
and Organelle DNA 299 12.3 Bacterial Replication Requires a Large
Number of Enzymes and Proteins 334
Telomeres and Childhood Adversity 299
Initiation 334
11.1 Large Amounts of DNA Are Packed into a Unwinding 33 4
Cell 300 Elongation 336
Supercoiling 300 Termination 339
The Bacterial Chromosome 301 The Fidelity of DNA Replkation 339
Eukarrotic Chron1oson1es 302
CONNECTING CONCEPTS The Basic Rul es of Replication 340
Changes in Chromatin Structure 304
Contents ix
12.4 Eukaryotic DNA Replication Is Similar to Initiation 371
Bacterial Replication but Differs in Several Elongation 373
Aspects 340 Termination 373
Eukaryotic Origins 340
13.5 Transcription in Archaea Is More Similar
The Licensing of DNA Replication 341
to Transcription in Eukaryotes Than to
Unwinding 341 Transcription in Eubacteria 374
Eukaryotic DNA Polymerases 341
Nucleo.son1e A~s.en1bly 342
Chapter 14 RNA Molecules and
The Location of Replication \'l'ithin the
RNA Processing 383
Nucleus 343
DNA Synthesis and the CeU Cycle 343 A Royal Disease 383
Replication at t he Ends of
14.1 Many Genes Have Complex Structures 384
Chron1oson1e.s 344
Gene Organiz~tion 384
Replication in Archaea 346
lntrons 385
12.5 Recombination Takes Place Through the
The Concept of the Gene Retisited 387
Breakage, Alignment, and Repair of DNA
14.2 Messenger RNAs. Which Encode the Amino
Strands 346
Acid Sequences of Proteins, Are Modified
Models of Recombination 347
after Transcription in Eukaryotes 387
Enzymes Required for Recombination 348
The Structnre of Messenger RNA 387
C'rene Conversion 349
Pre· mRNA Processing 388
1
The Addition of the 5 Cap 388
The Addition of the Poly( A) Tail 389
Chapter 13 Transcription 357
RNA Splicing 390
Death Cap Poisoning 357 Alternative Processing Path\'lays 393
RNA Editing 3 95
13.1 RNA .• Consisting of a Single Strand of
Ribonucleotides, Participates in a Variety of
CONNECTING CONCEPTS Eukaryotic Gene Structure and
Cellular Functions 3 58
Pre·mRNA Processing 396
An Early RNA World 358
The Structure of RNA 3 58
14.3 Transfer RNAs, Which Attach to Amino Acids,
Classes of RNA 359
Are Modified after Transcription in Bacterial
and Eukaryotic Cells 397
13.2 Transcription Is the Synthesis of an RNA
The Structure of Transfer RNA 398
Molecule from a DNA Template 360
Transfer RNA C',ene Structure and
The Template 361
Processing 399
The Substrate for Transcription 363
The Transcription Apparatus 363 14.4 Ribosomal RNA, a Component of the
Ribosome. Is Also Processed after
13.3 Bacterial Transcription Consists of Initiation,
Transcription 400
Elongation, and Termination 365
The Structnre of the Ribosome 400
Initiation 365
Ribosomal RNA Gene Structure and
Elongation 367
Processing 401
Ternlination 368
14.5 Small RNA Molecules Participate in a Variety
CONNECTING CONCEPTS The Basic Rules of
of Functions 402
Transcription 369
Ri"JA Interference 402
Small Interfering and Micro RNAs 403
13.4 Eukaryotic Transcription Is Similar to Bacterial
Piwi·I nteracting RNAs 404
Transcription but Has Some Important
CRISPR RNA 404
Differences 370
Transcription and Nucleoson1eStructnre 370 14.6 Long Noncoding RNAs Regulate Gene
Promoters 3 70 Expression 405
x Contents
Negative and Positive Control: Inducible and
Chapter 15 The Genetic Code and
Repressible Operons 448
Translation 411
The lac Operon of E.coli 450
Hutterites, Ribosomes, and
lac Mutations 453
Bowen-Conradi Syndrome 4 11 Positive Control and Catabolite Repression 457
The trp Operon of E. e-0/i 458
15.1 Many Genes Encode Proteins 412
Bacterial Enhancen; 460
The One Gene, One Enzyme Hypothesis 412
The Structure and Function of Proteins 415 16.3 Some Operons Regulate Transcription
Through Attenuation, the Premature
15.2 The Genetic Code Determines How the
Termination of Transcription 460
Nucleotide Sequence Specifies the Amino
Attenuation in the trp Operon of E. coli 460
Acid Sequence of a Protein 41 7
Why Does Attenuation Take Place in the trp
Breaking the Genetic Code 418
Operon? 464
The Degeneracy of the Code 420
The Reading Frame and Initiation Cod ons 421 16.4 RNA Molecules Control the Expression of
Termination Codons 422 Some Bacterial Genes 464
The Universality of the Code 422 AntL<ense RNA 464
Riboswitches 464
CONNECTING CONCEPTS Characteristics of the Genetic
RNA-Mediated Repres_~on Throug h
Code 422
Ribozymes 466
15.3 Amino Acids Are Assembled into a Protein
Through Translation 422 Chapter 17 Control of Gene
The Binding of Amino Acids to Transfer IU'1As 423 Expression in Eukaryotes 473
The Initiation of Translation 424
Genetic Differences That Make Us
Elongation 426
Human 473
Termination 427
17. 1 Eukaryotic Cells and Bacteria Have Many
CONNECTING CONCEPTS A Comparison of Bacterial and
Features of Gene Regulation in Common, but
Eukaryotic Translation 430
They Differ in Several Important Ways 474
15.4 Additional Properties of RNA and Ribosomes 17.2 Changes in Chromatin Structure Affect the
Affect Protein Synthesis 430 Expression of Genes 474
The Three· Dinlensional Structure of the DNase I Hypersensitivity 474
Ribosome 430 Ch romatin Remodeling 475
Polyribosomes 43 1 Hi<tone Modification 475
Messenger RNA Surveillance 431 DNA Methylation 478
Folding and Po sttranslational Modific~tions of
17.3 The Initiation of Transcription Is Regulated
Proteins 433 by Transcription Factors and Transcriptional
Translation and Antibiotics 433 Regulator Proteins 479
Transcriptional Activators and Coactivators 479
Transcriptional Repressors 481
Chapter 16 Control of Gene
Enhancers and l nsulaton; 481
Expression in Bacteria 443
Regulation of Transcriptional Stalling and
Operons and the Noisy Cell 443 Elongation 482
Coordinated Gene Regulation 482
16.1 The Regulation of Gene Expression Is Critical
for All Organisms 444 17.4 Some Gen es Are Regulated by RNA
Genes and Regulatory Element< 445 Processing and Degradation 483
LeveLrnfGene Regulation 445 Gene Regulation Through RNA Splicing 483
DNA-Bind ing Proteins 446 The Degradation of RNA 484
16.2 Operons Control Transcription in Bacterial 17.5 RNA Interference Is an Important Mechanism
Cells 447 of Gene Regulation 485
Operon Structure 447 Small Interfering RNAs and MicroRNA.< 485
Contents xi
Mech anisms of Gene Regulation by RNA
CONNECTING CONCEPTS The Basi c Pathway of DNA
Interference 486
Repair 524
The C.ontrol of Development by RNA
Repair of Doubte~5trand Breaks 524
Interference 487
Translesion DNA Polymerases 524
17.6 Some Genes Are Regulated by Processes That
Genetic Dl<eases and Faulty DNA Repair 525
Affect Translation or by Modifications of
Proteins 487
Chapter 19 Molecular Genetic
CONNECTING CONCEPTS A Compa rison of Bacterial and
Eukaryotic Gene Control 488 Analysis and Biotechnology 535
Helping the Blind to See 535
Chapter 18 Gene Mutations and
19.1 Techniques of Molecular Genetics Have
DNA Repair 493
Revolutionized Biology 536
The Molecular C'.enetics Revolution 536
A Fly Without a Heart 493
Working at the Molecular Level 536
18.1 Mutations Are Inherited Alterations in the
19.2 Molecular Techniques Are Used to Isolate,
DNA Sequence 494
Recombine, and Amplify Genes 537
The Importance of Mutations 494
Cutting and Joining DNA Fragment< 537
C"..ategories of Mutations 494
Viewing DNA Fragments 539
Types of C'.ene Mutations 495
Locating DNA Fragment< with Southern Blotting and
Phenotypic Effects of Mutations 497
Probes 540
Suppressor Mutations 498
Cloning Genes 541
Mutation Rates 502
Application: The Genetic Engineering of Plant< with
18.2 Mutations Are Potentially Caused by a
Pestkides 545
Number of Different Factors 503
Amplifying DNA Fragments with the Polymerase
Spontaneous Replkation Error.; 503
Chain Reaction 546
Spontane.ous Chemical Changes 504
19.3 Molecular Techniques Can Be Used to Find
ChemicaUy Induced Mutations 506
Genes of Interest 549
Radiation 508
Gene Libraries 549
18.3 Mutations Are the Focus of Intense Study by
In Situ Hybridization 552
Geneticists 509
Positional Cloning 552
Detecting Mutations \'lith the An1es Test 509
Application: l<olating the Gene for Cystk Fibrosl< 553
Radiation Exposure in Hun1ans 510
19.4 DNA Sequences Can Be Determined and
18.4 Transposable Elements Cause Mutations 511 Analyzed 555
C'.eneral Characteristics of Transposable Element< 5 11 Restriction Fragment Length Polymorphisms 555
Transposition 512 DNA Sequencing 556
The Mutagenic Effects of Transposition 513 Next-Generation Sequencing Technologies 559
Transposable Elements in Bacteria 514 DNA Fingerprinting 561
Transposable Elements in Eukaryotes 515 Application: Identifying People Who Died in the
Collapse of the World Trade C,enter 562
CONNECTING CONCEPTS Types ofTransposable
Elements 519 19.5 Molecular Techniques Are Increasingly Used
to Analyze Gene Function 563
Transposable Elements Have Played an
Forward and Reverse Genetics 563
ln1portant Role in Genon1e Evolution 520
Creating Random Mutations 564
18.5 A Number of Pathways Repair Changes in Site-Directed Mutagenesis 564
DNA 520 Transgenic Animals 565
lvfismatch Repair 520 Knockout Mke 566
Direct Repair 522 Silencing Genes with RNAi 567
Ba.<e· Excision Repair 522 Application: Using Rl'lAi to Treat Human
Nucleotide-Excision Repair 523 Disease 568
xii Contents
19.6 Biotechnology Harnesses the Power of 21.2 Several Molecular Processes Lead to
Molecular Genetics 569 Epigenetic Changes 615
Pharmaceutical Produrn 569 DNA Methylation 615
Specialized Bacteria 569 H istone Modifications 617
Agrkultural Products 569 Epigenetic Effects by RNA Molecules 618
Genetk Testing 570
21.3 Epigenetic Processes Produce a Diverse Set of
Gene Therapy 571
Effects 619
Paran1utation 619
Chapter 20 Genomics and
Behavioral Epigenetks 621
Proteomics 579
Epigenetic Effects of Environmental C.hemical< 623
Decoding the Waggle Dance: The Genome Transgenerational Epigenetic Efti?cts on
of the Honeybee 579 Metabolism 623
Epigenetic Effects in Monozygotic Twins 623
20. 1 Structural Genomics Determines the DNA
X Inactivation 623
Sequences of Entire Genomes 580
Epigenetic Changes Associated with Cell
Genetk Maps 580
Differentiation 625
Physkal Maps 581
Genomk Imprinting 626
Sequencing an Entire Genome 582
The Human Genome Project 583 21.4 The Epigenome 627
Single-Nucleotide Polymorphisms 587
Copy· Number Variations 588 Chapter 22 Developmental
Sequence-Tagged Sites and Expressed ..Sequence
Genetics and lmmunogenetics 633
Tags 589
Bioinformatics 589 The Origin of Spineless Sticklebacks 633
Metagenomics 590 22.1 Development Takes Place Through Cell
Synthetk Biology 591 Determination 634
20.2 Functional Genomics Determines the Cloning Experiments on Plants 635
Function of Genes by Using Genomic-Based Cloning E'"periments on Animals 635
Approaches 591
22.2 Pattern Formation in Drosophila Serves
Predicting Function from Sequ ence 591
As a Model for the Genetic Control of
Gene E.'Xpression and ~'1 icroarrays 592
Development 636
Gene Expression and Reporter Sequences 595 The Development of the Fruit Fly 636
Genon1e. . \<\'ide !Ylutagenesis 595
Egg-Polarity Genes 637
20.3 Comparative Genomics Studies How Segmentation Genes 640
Genomes Evolve 596 Hon1eotk Genes in Drosopllila 640
PmkaryoticGenomes 596 Hon1eobox. C'Jt>nes in Other Organisn1s 642
Eukarrotic C,enon1es 598
CONNECTING CONCEPTS The Control Of Developm ent 643
Con1parative Drosophila Genon1ks 601
The Human Genome 601 Epigenetic Changes in Development 643
20.4 Proteomics Analyzes the Complete Set of 22.3 Genes Control the Development of Flowers in
Proteins Found in a Cell 603 Plants 644
Determination of Cellular Proteins 603 Flo,V'er Anaton1y 644
Affinity Capture 604 Genetic C'Amtrol of Flower Development 644
Protein Mkroarrays 604
CONNECTING CONCEPTS Comparison of Development in
Structural Proteon1ics 605
Drosophila and Flowers 646
Chapter 21 Epigenetics 613
22.4 Programmed Cell Death Is an Integral Part of
How Your Grandfather's Diet Could Affect
Development 646
Your Health 613
22.5 The Study of Development Reveals Patterns
21. 1 What Is Epigenetics? 614 and Processes of Evolution 647
Contents xiii
22.6 The Development of Immunity Is Through Kernel Color in Wheat 687
Genetic Rearrangement 649 Detern1ining Gene Nun1ber for a Polygenic
The Organizatfon of the ln1n1uneSysten1 650 Characteristk 688
Jmmunoglobulin Structure 651
24.2 Statistical Methods Are Required for
The Generation of Antibody Diversity 652
Analyzing Quantitative Characteristics 689
T· Cell· Receptor Diveraity 653
Distributions 689
Major Histocompatibility Complex Genes 654
Samples and Populations 690
C'><?nes and Organ Transplants 6 54
The Mean 690
The Variance and Standard Deviation 691
Chapter 23 Cancer Genetics 661 Correlation 692
Regression 693
Palladin and the Spread of Cancer 661
ApplyingStatistks to the Study of a Polygenk
23.1 Cancer Is a Group of Diseases Characterized Characteristk 695
by Cell Proliferation 662
24.3 Heritability Is Used to Estimate the
Tu n1or Forn1ation 662
Proportion of Variation in a Trait That
C'..ancer As a Genetk Di.<;ease 663
Is Genetic 696
The Role of Environn1ental Factors in Cancer 665
Ph enotypic Variance 696
23.2 Mutations in a Number of Different Types of
Types of Heritability 698
Genes Contribute to Cancer 666
Caln tlating Heritability 698
Oncogenes and Tumor-Suppressor Genes 666
The Limitations of Heritability 700
Mutations in Genes That Control the Cycle of Cell
Locating Gen es That Affect Quantitative
Division 668
Characteristks 702
DNA-Repair Genes 672
C'><?nes That RegLtlateTelomerase 672 24.4 Genetically Variable Traits Change in
Cienes That Pmn1ote Va<;culariz.ation and t he Spread Response to Selection 704
ofTumors 672 Predkting the Response to Selection 705
lvlicroRNAs and Cancer 6 73 Limit< to Selection Response 706
Cmcer Genome Projects 674 Correlated Responses 707
23.3 Epigenetic Changes Are Often Associated
with Cancer 674 Chapter 25 Population Genetics 715
23.4 Colorectal Cancer Arises Through the
Genetic Rescue of Bighorn Sheep 715
Sequential Mutation of a Number of
Genes 675 25.1 Genotypic and Allelic Frequencies Are Used to
Describe the Gene Pool of a Population 716
23.5 Changes in Chromosome Number and
Calculating C'.enotypic Frequencies 717
Structure Are Often Associated with
Calculating Allelk Frequencies 717
Cancer 676
23.6 Viruses Are Associated with Some Cancers 678 25.2 The Hardy- Weinberg law Describes the
Effect of Reproduction on Genotypic and
Allelic Frequencies 719
Chapter 24 Quantitative
Genotypic Frequencies at Hardy- Weinberg
Genetics 683
Equilibrium 719
Closer Exan1ination of the Hardy- Weinberg Law 720
Corn Oil and Quantitative Genetics 683
Implications of the Hardy- Weinberg Law 720
24. 1 Quantitative Characteristics Vary
Extensions of the Hardy- Weinberg Law 721
Continuously and Many Are Influenced by
Testing for Hardy- Weinberg Proportions 721
Alleles at Multiple loci 684
Estin1ating Allelic Frequencies \\1ith the
The Relation Between Genotype and
Hardy- Weinberg Law 722
Phenotype 684
Types of Quantitative Ch aracteristics 686 25.3 Nonrandom Mating Affects the Genotypic
Polygenic Inheritance 686 Frequencies of a Population 723