Essential Cell Biology 5th edition

Contents
xxi
POST-TRANSCRIPTIONAL CONTROLS 287
mRNAs Contain Sequences That Control Their Translation 288
Regulatory RNAs Control the Expression of Thousands of Genes 288
MicroRNAs Direct the Destruction of Target mRNAs 289
Small Interfering RNAs Protect Cells From Infections 290
Thousands of Long Noncoding RNAs May Also Regulate Mammalian Gene Activity 291
ESSENTIAL CONCEPTS 292
QUESTIONS 293
CHAPTER 9
How Genes and Genomes Evolve 297
GENERATING GENETIC VARIATION 298
In Sexually Reproducing Organisms, Only Changes to the Germ Line
Are Passed On to Progeny 299
Point Mutations Are Caused by Failures of the Normal Mechanisms
for Copying and Repairing DNA 300
Mutations Can Also Change the Regulation of a Gene 302
DNA Duplications Give Rise to Families of Related Genes 302
Duplication and Divergence Produced the Globin Gene Family 304
Whole-Genome Duplications Have Shaped the Evolutionary History of Many Species 306
Novel Genes Can Be Created by Exon Shuffling 306
The Evolution of Genomes Has Been Profoundly Influenced by Mobile Genetic Elements 307
Genes Can Be Exchanged Between Organisms by Horizontal Gene Transfer 308
RECONSTRUCTING LIFE’S FAMILY TREE 309
Genetic Changes That Provide a Selective Advantage Are Likely to Be Preserved 309
Closely Related Organisms Have Genomes That Are Similar
in Organization as Well as Sequence 310
Functionally Important Genome Regions Show Up as Islands of Conserved DNA Sequence 310
Genome Comparisons Show That Vertebrate Genomes Gain and Lose DNA Rapidly 313
Sequence Conservation Allows Us to Trace Even the Most Distant Evolutionary Relationships 313
MOBILE GENETIC ELEMENTS AND VIRUSES 315
Mobile Genetic Elements Encode the Components They Need for Movement 315
The Human Genome Contains Two Major Families of Transposable Sequences 316
Viruses Can Move Between Cells and Organisms 317
Retroviruses Reverse the Normal Flow of Genetic Information 318
EXAMINING THE HUMAN GENOME 320
The Nucleotide Sequences of Human Genomes Show How Our Genes Are Arranged 321
Differences in Gene Regulation May Help Explain How Animals with Similar Genomes Can Be So Different 323
The Genome of Extinct Neanderthals Reveals Much about What Makes Us Human 326
Genome Variation Contributes to Our Individuality—But How? 327
ESSENTIAL CONCEPTS 328
QUESTIONS 329