Principles of Genetics, Sixth Edition
Buy Rights Online Buy Rights

Rights Contact Login For More Details

More About This Title Principles of Genetics, Sixth Edition


Principles of Genetics is one of the most popular texts in use for the introductory course. It opens a window on the rapidly advancing science of genetics by showing exactly how genetics is done. Throughout, the authors incorporate a human emphasis and highlight the role of geneticists to keep students interested and motivated. The sixth edition has been updated to reflect the latest developments in the field of genetics. Principles of Genetics continues to educate today’s students for tomorrow’s science by focusing on features that aid in content comprehension and application.


D. Peter Snustad is a Professor Emeritus at the University of Minnesota, Twin Cities. He received his B.S. degree from the University of Minnesota and his M.S. and Ph.D. degrees from the University of California, Davis. He began his faculty career in the Department of Agronomy and Plant Genetics at Minnesota in 1965, became a charter member of the new Department of Genetics in 1966, and moved to the Department of Plant Biology in 2000. During his 43 years at Minnesota, he taught courses ranging from general biology to biochemical genetics. His initial research focused on the interactions between bacteriophage T4 and its host, E. coli. In the 1980s, his research switched to the cytoskeleton of Arabidopsis and the glutamine synthetase genes of corn. His honors include the Morse-Amoco and Dagley Memorial teaching awards and election to Fellow of the American Association for the Advancement of Science. A lifelong love of the Canadian wilderness has kept him in nearby Minnesota.

Michael J. Simmons is a Professor in the Department of Genetics, Cell Biology and Development at the University of Minnesota, Twin Cities. He received his B.A. degree in biology from St. Vincent College in Latrobe, Pennsylvania, and his M.S. and Ph.D. degrees in genetics from the University of Wisconsin, Madison. Dr. Simmons has taught a variety of courses, including genetics and population genetics. He has also mentored many students on research projects in his laboratory. Early in his career he received the Morse-Amoco teaching award from the University of Minnesota in recognition of his contributions to undergraduate education. Dr. Simmons’s research focuses on the genetic significance of transposable elements in the genome of Drosophila melanogaster. He has served on advisory committees at the National Institutes of Health and was a member of the Editorial Board of the journal Genetics for 21 years. One of his favorite activities, figure skating, is especially compatible with the Minnesota climate.



The Science of Genetics 1

An Invitation 2

Three Great Milestones in Genetics 2

DNA as the Genetic Material 6

Genetics and Evolution 10

Levels of Genetic Analysis 11

Genetics in the World: Applications of Genetics to Human Endeavors 12


Cellular Reproduction 18

Cells and Chromosomes 19

Mitosis 24

Meiosis 27

Life Cycles of Some Model Genetic Organisms 32


Mendelism: The Basic Principles of Inheritance 40

Mendel’s Study of Heredity 41

Applications of Mendel’s Principles 46

Testing Genetic Hypotheses 48

Mendelian Principles in Human Genetics 52


Extensions of Mendelism 62

Allelic Variation and Gene Function 63

Gene Action: From Genotype to Phenotype 70

Inbreeding: Another Look at Pedigrees 77


The Chromosomal Basis of Mendelism 89

Chromosomes 90

The Chromosome Theory of Heredity 92

Sex-Linked Genes in Humans 98

Sex Chromosomes and Sex 98

Determination 100

Dosage Compensation of X-Linked Genes 104


Variation in Chromosome Number and Structure 110

Cytological Techniques 111

Polyploidy 115

Aneuploidy 119

Rearrangements of Chromosome Structure 126


Linkage, Crossing Over, and Chromosome Mapping in Eukaryotes 135

Linkage, Recombination, and Crossing Over 136

Chromosome Mapping 141

Cytogenetic Mapping 148

Linkage Analysis in Humans 150

Recombination and Evolution 153


The Genetics of Bacteria and Their Viruses 163

Viruses and Bacteria in Genetics 164

The Genetics of Viruses 165

The Genetics of Bacteria 169

Mechanisms of Genetic Exchange in Bacteria 172

The Evolutionary Significance of Genetic Exchange in Bacteria 186


DNA and the Molecular Structure of Chromosomes 192

Functions of the Genetic Material 193

Proof That Genetic Information Is Stored in DNA 193

The Structures of DNA and RNA 197

Chromosome Structure in Prokaryotes and Viruses 205

Chromosome Structure in Eukaryotes 207


Replication of DNA and Chromosomes 220

Basic Features of DNA Replication In Vivo 221

DNA Replication in Prokaryotes 231

Unique Aspects of Eukaryotic Chromosome Replication 244


Transcription and RNA Processing 256

Transfer of Genetic Information: The Central Dogma 257

The Process of Gene Expression 259

Transcription in Prokaryotes 263

Transcription and RNA Processing in Eukaryotes 267

Interrupted Genes in Eukaryotes: Exons and Introns 274

Removal of Intron Sequences by RNA Splicing 277


Translation and the Genetic Code 285

Protein Structure 286

One Gene—One Colinear Polypeptide 289

Protein Synthesis: Translation 293

The Genetic Code 306

Codon-tRNA Interactions 312


Mutation, DNA Repair, and Recombination 320

Mutation: Source of the Genetic Variability Required for Evolution 321

The Molecular Basis of Mutation 321

Mutation: Basic Features of the Process 332

Mutation: Phenotypic Effects 337

Assigning Mutations to Genes by the Complementation Test 342

Screening Chemicals for Mutagenicity: The Ames Test 346

DNA Repair Mechanisms 348

Inherited Human Diseases with Defects in DNA Repair 351

DNA Recombination Mechanisms 354


The Techniques of Molecular Genetics 366

Basic Techniques Used to Identify, Amplify, and Clone Genes 367

Construction and Screening of DNA Libraries 377

The Molecular Analysis of DNA, RNA, and Protein 380

The Molecular Analysis of Genes and Chromosomes 386


Genomics 397

Genomics: An Overview 402

Correlated Genetic, Cytological, and Physical Maps of Chromosomes 402

Map Position-Based Cloning of Genes 407

The Human Genome Project 409

RNA and Protein Assays of Genome Function 415

Comparative Genomics 420


Applications of Molecular Genetics 439

Use of Recombinant DNA Technology to Identify Human Genes and Diagnose Human Diseases 440

Molecular Diagnosis of Human Diseases 448

Human Gene Therapy 450

DNA Profiling 455

Production of Eukaryotic Proteins in Bacteria 461

Transgenic Plants and Animals 463

Reverse Genetics: Dissecting Biological Processes by Inhibiting Gene Expression 467


Transposable Genetic Elements 477

Transposable Elements: An Overview 478

Transposable Elements in Bacteria 479

Cut-and-Paste Transposons in Eukaryotes 483

Retroviruses and Retrotransposons 488

Transposable Elements in Humans 494

The Genetic and Evolutionary Significance of Transposable Elements 496


Regulation of Gene Expression in Prokaryotes 504

Constitutive, Inducible, and Repressible Gene Expression 506

Positive and Negative Control of Gene Expression 507

Operons: Coordinately Regulated Units of Gene Expression 509

The Lactose Operon in E. coli: Induction and Catabolite Repression 511

The Tryptophan Operon in E. coli: Repression and Attenuation 519

Translational Control of Gene Expression 525

Posttranslational Regulatory Mechanisms 526


Regulation of Gene Expression in Eukaryotes 531

Ways of Regulating Eukaryotic Gene Expression: An Overview 532

Induction of Transcriptional Activity by Environmental and Biological Factors 534

Molecular Control of Transcription in Eukaryotes 537

Posttranscriptional Regulation of Gene Expression by RNA Interference 541

Gene Expression and Chromatin Organization 544

Activation and Inactivation of Whole Chromosomes 550


The Genetic Control of Animal Development 558

A Genetic Perspective on Development 559

Maternal Gene Activity in Development 561

Genetic Analysis of Development in Vertebrates 571


The Genetic Basis of Cancer 581

Cancer: A Genetic Disease 582

Oncogenes 585

Tumor Suppressor Genes 590

Genetic Pathways to Cancer 600


Inheritance of Complex Traits 607

Complex Traits 608

Statistics of Quantitative Genetics 611

Analysis of Quantitative Traits 613

Correlations Between Relatives 624

Quantitative Genetics of Human Behavioral Traits 628


Population Genetics 634

The Theory of Allele Frequencies 635

Natural Selection 641

Random Genetic Drift 645

Populations in Genetic Equilibrium 647


Evolutionary Genetics 656

The Emergence of Evolutionary Theory 657

Genetic Variation in Natural Populations 659

Molecular Evolution 662

Speciation 672

Human Evolution 676


Appendix A: The Rules of Probability 685

Appendix B: Binomial Probabilities 687

Appendix C: In Situ Hybridization 689

Appendix D: Evidence for an Unstable Messenger RNA 691

Appendix E: Evolutionary Rates 693

Answers to Odd-Numbered Questions and Problems 697

Glossary 720

Photo Credits 743

Illustration Credits 745

Index 746