内容

目次

Preface. 1. An Introduction to Genetics. Genetics Has a Rich andInteresting History. Nucleic Acids and Proteins Serve as the Molecular Basisof Genetics. Genetics Has Been Investigated Using Many Different Approaches.Genetics Has a Profound Impact on Society. GENETICS, TECHNOLOGY, AND SOCIETY.The Frankenfood Debates: Genetically Modified Foods. Chapter Summary. KeyTerms. Problems and Discussion Questions. Selected Readings. 2. Mitosis andMeiosis. Cell Structure Is Closely Tied to Genetic Function. ChromosomesExist in Homologous Pairs in Diploid Organisms. Mitosis PartitionsChromosomes into Dividing Cells. The Cell Cycle Is Genetically Regulated.Meiosis Reduces the Chromosome Number from Diploid to Haploid in Germ Cellsand Spores. The Development of Gametes Varies During Spermatogenesis andOogenesis. Meiosis Is Critical to the Successful Sexual Reproduction of AllDiploid Organisms. Electron Microscopy Has Revealed the Cytological Nature ofMitotic and Meiotic Chromosomes. Chapter Summary. Key Terms. Insights andSolutions. Problems and Discussion Questions. Selected Readings. 3.Mendelian Genetics. Mendel Used a Model Experimental Approach to StudyPatterns of Inheritance. The Monohybrid Cross Reveals How One Trait IsTransmitted from Generation to Generation. Mendel's Dihybrid Cross Generateda Unique F2 Ratio. The Trihybrid Cross Demonstrates that Mendel's PrinciplesApply to Inheritance of Multiple Traits. Mendel's Work Was Rediscovered inthe Early Twentieth Century. Independent Assortment Leads to ExtensiveGenetic Variation. Laws of Probability Help to Explain Genetic Events. HowMendel's Peas Become Wrinkled: A Molecular Explanation. Chi-Square AnalysisEvaluates the Influence of Chance on Genetic Data. Pedigrees Reveal Patternsof Inheritance in Humans. Chapter Summary. Key Terms. Insights and Solutions.Problems and Discussion Questions. Selected Readings. 4. Modification ofMendelian Ratios. Alleles Alter Phenotypes in Different Ways. GeneticistsUse a Variety of Symbols for Alleles. Neither Allele Is Dominant inIncomplete, or Partial, Dominance. In Codominance, the Influence of BothAlleles in a Heterozygote Is Clearly Evident. Multiple Alleles of a Gene MayExist in a Population. Lethal Alleles Represent Essential Genes. Combinationsof Two Gene Pairs with Two Modes of Inheritance Modify the 9:3:3:1 Ratio.Phenotypes Are Often Affected by More than One Gene. Complementation AnalysisCan Determine if Two Mutations Causing a Similar Phenotype Are Alleles.X-Linkage Describes Genes on the X Chromosome. In Sex-Limited andSex-Influenced Inheritance, an Individual's Sex Influences the Phenotype.Phenotypic Expression Is Not Always a Direct Reflection of the Genotype.Extranuclear Inheritance Modifies Mendelian Patterns. GENETICS, TECHNOLOGY,AND SOCIETY. Improving the Genetic Fate of Purebred Dogs. Chapter Summary.Key Terms. Insights and Solutions. Problems and Discussion Questions.Selected Readings. 5. Sex Determination and Sex Chromosomes. Life CyclesDepend on Sexual Differentiation. X and Y Chromosomes Were First Linked toSex Determination Early in the Twentieth Century. The Y Chromosome DeterminesMaleness in Humans. The Ratio of Males to Females in Humans Is Not 1.0.Dosage Compensation Prevents Excessive Expression of X-Linked Genes in Humansand Other Mammals. The Ratio of X Chromosomes to Sets of Autosomes DeterminesSex in Drosophila. Temperature Variation Controls Sex Determination inReptiles. GENETICS, TECHNOLOGY, AND SOCIETY. A Question of Gender: SexSelection in Humans. Chapter Summary. Key Terms. Insights and Solutions.Problems and Discussion Questions. Selected Readings. 6. QuantitativeGenetics. Continuous Variation Characterizes the Inheritance of QuantitativeTraits. The Study of Polygenic Traits Relies on Statistical Analysis.Heritability Is a Measure of the Genetic Contribution to PhenotypicVariability. Quantitative Trait Loci Can Be Mapped. GENETICS, TECHNOLOGY, ANDSOCIETY. The Green Revolution Revisited. Chapter Summary. Key Terms. Insightsand Solutions. Problems and Discussion Questions. Selected Readings. 7.Chromosome Mutations: Variation in Number and Arrangement. SpecificTerminology Describes Variations in Chromosome Number. Variation in theNumber of Chromosomes Results from Nondisjunction. Monosomy, the Loss of aSingle Chromosome, May Have Severe Phenotypic Effects. Trisomy Involves theAddition of a Chromosome to a Diploid Genome. Polyploidy, in Which More thanTwo Haploid Sets of Chromosomes Are Present, Is Prevalent in Plants.Variation Occurs in the Structure and Arrangement of Chromosomes. A DeletionIs a Missing Region of a Chromosome. A Duplication Is a Repeated Segment of aChromosome. Inversions Rearrange the Linear Gene Sequence. TranslocationsAlter the Location of Chromosomal Segments in the Genome. Fragile Sites inHumans Are Susceptible to Chromosome Breakage. Chapter Summary. Key Terms.Insights and Solutions. Problems and Discussion Questions. Selected Readings.8. Linkage and Chromosome Mapping in Eukaryotes. Genes Linked on the SameChromosome Segregate Together. Crossing over Serves as the Basis ofDetermining the Distance Between Genes During Mapping. Determining the GeneSequence During Mapping Relies on the Analysis of Multiple Crossovers. As theDistance Between Two Genes Increases, Mapping Estimates Become MoreInaccurate. Drosophila Genes Have Been Extensively Mapped. Lod Score Analysisand Somatic Cell Hybridization Were Historically Important in Creating HumanChromosome Maps. Linkage and Mapping Studies Can Be Performed in HaploidOrganisms. Other Aspects of Genetic Exchange. Did Mendel Encounter Linkage?Why Didn't Gregor Mendel Find Linkage? Chapter Summary. Key Terms. Insightsand Solutions. Problems and Discussion Questions. Selected Readings. 9.Mapping in Bacteria and Bacteriophages. Bacteria Mutate Spontaneously andGrow at an Exponential Rate. Conjugation Is One Means of GeneticRecombination in Bacteria. Rec Proteins Are Essential to BacterialRecombination. F Factors Are Plasmids. Transformation Is Another ProcessLeading to Genetic Recombination in Bacteria. Bacteriophages Are BacterialViruses. Transduction Is Virus-Mediated Bacterial DNA Transfer.Bacteriophages Undergo Intergenic Recombination. GENETICS, TECHNOLOGY, ANDSOCIETY. Eradicating Cholera: Edible Vaccines. Chapter Summary. Key Terms.Insights and Solutions. Problems and Discussion Questions. Selected Readings.10. DNA Structure and Analysis. The Genetic Material Must Exhibit FourCharacteristics. Until 1944, Observations Favored Protein as the GeneticMaterial. Evidence Favoring DNA as the Genetic Material Was First ObtainedDuring the Study of Bacteria and Bacteriophages. Indirect and Direct EvidenceSupports the Concept that DNA Is the Genetic Material in Eukaryotes. RNAServes as the Genetic Material in Some Viruses. The Structure of DNA Holdsthe Key to Understanding Its Function. Molecular Structure of Nucleic Acids:A Structure for Deoxyribose Nucleic Acid. Alternative Forms of DNA Exist. TheStructure of RNA Is Chemically Similar to DNA, but Single-Stranded. ManyAnalytical Techniques Have Been Useful During the Investigation of DNA andRNA. Nucleic Acids Can Be Separated Using Electrophoresis. GENETICS,TECHNOLOGY, AND SOCIETY. The Twists and Turns of the Helical Revolution.Chapter Summary. Key Terms. Insights and Solutions. Problems and DiscussionQuestions. Selected Readings. 11. DNA-Replication and Synthesis. DNA IsReproduced by Semiconservative Replication. DNA Synthesis in BacteriaInvolves Three Polymerases, as Well as Other Enzymes. Many Complex IssuesMust Be Resolved During DNA Replication. A Coherent Model Summarizes DNAReplication. Replication Is Controlled by a Variety of Genes. Eukaryotic DNASynthesis Is Similar to, but More Complex than, Synthesis in Prokaryotes. TheEnds of Linear Chromosomes Are Problematic During Replication. DNARecombination, Like DNA Replication, Is Directed by Specific Enzymes.GENETICS, TECHNOLOGY, AND SOCIETY. Telomerase: The Key to Immortality?Chapter Summary. Key Terms. Insights and Solutions. Problems and DiscussionQuestions. Selected Readings. 12. Chromosome Structure and DNA SequenceOrganization. Viral and Bacterial Chromosomes Are Relatively Simple DNAMolecules. Mitochondria and Chloroplasts Contain DNA Similar to Bacteria andViruses. Specialized Chromosomes Reveal Variations in the Organization ofDNA. DNA Is Organized into Chromatin in Eukaryotes. Eukaryotic GenomesDemonstrate Complex Sequence Organization Characterized by Repetitive DNA.The Vast Majority of a Eukaryotic Genome Does Not Encode Functional Genes.Chapter Summary. Key Terms. Insights and Solutions. Problems and DiscussionQuestions. Selected Readings. 13. The Genetic Code and Transcription. TheGenetic Code Exhibits a Number of Characteristics. Early Studies Establishedthe Basic Operational Patterns of the Code. Studies by Nirenberg, Matthaei,and Others Deciphered the Code. The Coding Dictionary Reveals the Function ofthe 64 Triplets. The Genetic Code Has Been Confirmed in Studies ofBacteriophage MS2. The Genetic Code Is Nearly Universal. TranscriptionSynthesizes RNA on a DNA Template. RNA Polymerase Directs RNA Synthesis.Transcription in Eukaryotes Differs from Prokaryotic Transcription in SeveralWays. The Coding Regions of Eukaryotic Genes Are Interrupted by InterveningSequences. RNA Editing Modifies the Final Transcript. GENETICS, TECHNOLOGY,AND SOCIETY. Antisense Oligonucleotides: Attacking the Messenger. ChapterSummary. Key Terms. Insights and Solutions. Problems and DiscussionQuestions. Selected Readings. 14. Translation and Proteins. Translation ofmRNA Depends on Ribosomes and Transfer RNAs. Translation of mRNA Can BeDivided into Three Steps. Crystallographic Analysis Has Revealed Many DetailsAbout the Functional Prokaryotic Ribosome. Translation Is More Complex inEukaryotes. The Initial Insight that Proteins Are Important in Heredity WasProvided by the Study of Inborn Errors of Metabolism. Studies of NeurosporaLed to the One-Gene: One-Enzyme Hypothesis. Studies of Human HemoglobinEstablished that One Gene Encodes One Polypeptide. The Nucleotide Sequence ofa Gene and the Amino Acid Sequence of the Corresponding Protein ExhibitColinearity. Protein Structure Is the Basis of Biological Diversity.Posttranslational Modification Alters the Final Protein Product. ProteinFunction Is Directly Related to the Structure of the Molecule. ProteinsConsist of Functional Domains. GENETICS, TECHNOLOGY, AND SOCIETY. Mad Cowsand Heresies: The Prion Story. Chapter Summary. Key Terms. Insights andSolutions. Problems and Discussion Questions. Selected Readings. 15. GeneMutation, DNA Repair, and Transposable Elements. Mutations May Be Classifiedin Various Ways. Genetic Techniques, Cell Cultures, and Pedigree Analysis AreAll Used to Detect Mutations. The Spontaneous Mutation Rate Varies GreatlyAmong Organisms. Mutations Occur in Many Forms and Arise in Different Ways.Ultraviolet and Ionizing Radiation Are Mutagenic. Gene Sequencing HasEnhanced Understanding of Mutations in Humans. The Ames Test Is Used toAssess the Mutagenicity of Compounds. Organisms Can Counteract DNA Damage byActivating Several Types of Repair Systems. Site-Directed Mutagenesis AllowsResearchers to Investigate Specific Genes. Transposable Genetic Elements MoveWithin the Genome and May Disrupt Genetic Function. GENETICS, TECHNOLOGY, ANDSOCIETY. Chernobyl's Legacy. Chapter Summary. Key Terms. Insights andSolutions. Problems and Discussion Questions. Selected Readings. 16.Regulation of Gene Expression. Prokaryotes Exhibit Efficient GeneticMechanisms to Respond to Environmental Conditions. Lactose Metabolism in E.coli Is Regulated by an Inducible System. Crystal Structure Analysis ofRepressor Complexes Has Confirmed the Operon Model. Tryptophan Metabolism inE. coli Is Controlled by a Repressible Gene System. Eukaryotic GeneRegulation Differs from Regulation in Prokaryotes. Regulatory Elements andTranscription Factors Control the Expression of Eukaryotic Genes. SteroidHormones Regulate Some Genes. Posttranscriptional Events Also Regulate GeneExpression. GENETICS, TECHNOLOGY, AND SOCIETY. Why Is There No Effective AIDSVaccine? Chapter Summary. Key Terms. Insights and Solutions. Problems andDiscussion Questions. Selected Readings. 17. Recombinant DNA Technology.An Overview of Recombinant DNA Technology. Recombinant DNA Molecules AreConstructed Using Several Components. Cloning in Prokaryotic Host Cells.Cloning in Eukaryotic Host Cells. The Polymerase Chain Reaction PermitsCloning Without Host Cells. Libraries Are Collections of Cloned Sequences.Specific Clones Can Be Recovered from a Library. Cloned Sequences Can BeCharacterized in Several Ways. DNA Sequencing: The Ultimate Way toCharacterize a Clone. GENETICS, TECHNOLOGY, AND SOCIETY. Beyond Dolly: TheCloning of Humans. Chapter Summary. Key Terms. Insights and Solutions.Problems and Discussion Questions. Selected Readings. 18. Genomics,Bioinformatics, and Proteomics. Genomics: Sequencing Helps Identify and MapAll Genes in a Genome. Bioinformatics Provides Tools for Analyzing GenomicInformation. Functional Genomics Classifies Genes and Identifies TheirFunctions. Prokaryotic Genomes Have Some Unexpected Features. EukaryoticGenomes Have a Mosaic of Organizational Patterns. Genomics Provides Insightinto Genome Evolution. Comparative Genomics: Multigene Families DiversifyGene Function. Proteomics Identifies and Analyzes the Proteins in a Cell.GENETICS, TECHNOLOGY, AND SOCIETY. Footprints of a Killer. Chapter Summary.Key Terms. Insights and Solutions. Problems and Discussion Questions.Selected Readings. 19. Applications and Ethics of Biotechnology.Biotechnology Has Revolutionized Agriculture. Pharmaceutical Products AreSynthesized in Genetically Altered Organisms. Biotechnology Is Used toDiagnose and Screen Genetic Disorders. Genetic Disorders Can Be Treated byGene Therapy. Gene Therapy Raises Many Ethical Concerns. Ethical Issues Arean Outgrowth of the Human Genome Project. Mapping Human Genes withRecombinant DNA Technology. DNA Fingerprints Can Identify Individuals.GENETICS, TECHNOLOGY, AND SOCIETY. Gene Therapy-Two Steps Forward or TwoSteps Back? Chapter Summary. Key Terms. Insights and Solutions. Problems andDiscussion Questions. Selected Readings. 20. Genes and Development. BasicConcepts in Developmental Genetics. Maternal and Zygotic Genes Interact toEstablish the Body Axis in Drosophila. Homeotic Genes Control PatternFormation Along the Anterior-Posterior Body Axis. Cell-Cell Interactions CanControl Developmental Fate. GENETICS, TECHNOLOGY, AND SOCIETY. Stem CellWars. Chapter Summary. Key Terms. Insights and Solutions. Problems andDiscussion Questions. Selected Readings. 21. The Genetic Basis of Cancer.Cancer as a Disorder of the Cell Cycle. Genes that Control the Cell Cycle AreInvolved in Cancer. Tumor-Suppressor Genes Repress Cell Division.Proto-oncogenes Promote or Maintain Cell Division. Colon Cancer as a GeneticModel of Cancer. The Pathway to Cancer Leads Through Gatekeeper and CaretakerGenes. Chromosomal Translocations Are a Hallmark of Leukemia. EnvironmentalFactors Contribute to Cancer. GENETICS, TECHNOLOGY, AND SOCIETY. TheDouble-Edged Sword of Genetic Testing: The Case of Breast Cancer. ChapterSummary. Key Terms. Insights and Solutions. Problems and DiscussionQuestions. Selected Readings. 22. Population Genetics. Populations andGene Pools. Calculating Allele Frequencies. The Hardy-Weinberg Law.Extensions of the Hardy-Weinberg Law. Using the Hardy-Weinberg Law:Calculating Heterozygote Frequency. Natural Selection. Mutation. Migration.Genetic Drift. Nonrandom Mating. GENETICS, TECHNOLOGY, AND SOCIETY. TrackingOur Genetic Footprints out of Africa. Chapter Summary. Key Terms. Insightsand Solutions. Problems and Discussion Questions. Selected Readings. 23.Genetics and Evolution. Speciation Can Occur by Transformation or Splittingof Gene Pools. Genetic Variation Is Present in Populations and Species.Explaining High Levels of Genetic Variation in Populations. The GeneticStructure of Populations Changes Across Space and Time. Reduced Gene Flow,Selection, and Drift Can Form New Species. Using Genetic Differences toReconstruct Evolutionary History. Evolutionary History Can Be Used to AnswerMany Questions. GENETICS, TECHNOLOGY, AND SOCIETY. What Can We Learn from theFailure of the Eugenics Movement? Chapter Summary. Key Terms. Insights andSolutions. Problems and Discussion Questions. Selected Readings. 24.Conservation Genetics. Genetic Diversity Is at the Heart of ConservationGenetics. Population Size Has a Major Impact on Species Survival. GeneticEffects Are More Pronounced in Small, Isolated Populations. Genetic ErosionDiminishes Genetic Diversity. Conservation of Genetic Diversity Is Essentialto Species Survival. GENETICS, TECHNOLOGY, AND SOCIETY. Gene Pools andEndangered Species: The Plight of the Florida Panther. Chapter Summary. KeyTerms. Insights and Solutions. Problems and Discussion Questions. SelectedReadings. Appendix: Answers to Selected Problems. Glossary. Index.