Essential Cell Biology 5th edition

Contents
xxxi
GENETICS AS AN EXPERIMENTAL TOOL 674
The Classical Genetic Approach Begins with Random Mutagenesis 674
Genetic Screens Identify Mutants Deficient in Specific Cell Processes 676
Conditional Mutants Permit the Study of Lethal Mutations 676
A Complementation Test Reveals Whether Two Mutations Are in the Same Gene 678
EXPLORING HUMAN GENETICS 678
Linked Blocks of Polymorphisms Have Been Passed Down from Our Ancestors 679
Polymorphisms Provide Clues to Our Evolutionary History 679
Genetic Studies Aid in the Search for the Causes of Human Diseases 680
Many Severe, Rare Human Diseases Are Caused by Mutations in Single Genes 681
Common Human Diseases Are Often Influenced by Multiple Mutations and Environmental Factors 682
Genome-wide Association Studies Can Aid the Search for Mutations Associated with Disease 683
We Still Have Much to Learn about the Genetic Basis of Human Variation and Disease 686
ESSENTIAL CONCEPTS 687
QUESTIONS 688
CHAPTER 20
Cell Communities: Tissues, Stem Cells,
and Cancer 691
EXTRACELLULAR MATRIX AND CONNECTIVE TISSUES 692
Plant Cells Have Tough External Walls 693
Cellulose Microfibrils Give the Plant Cell Wall Its Tensile Strength 694
Animal Connective Tissues Consist Largely of Extracellular Matrix 695
Collagen Provides Tensile Strength in Animal Connective Tissues 696
Cells Organize the Collagen They Secrete 697
Integrins Couple the Matrix Outside a Cell to the Cytoskeleton Inside It 698
Gels of Polysaccharides and Proteins Fill Spaces and Resist Compression 700
EPITHELIAL SHEETS AND CELL JUNCTIONS 701
Epithelial Sheets Are Polarized and Rest on a Basal Lamina 702
Tight Junctions Make an Epithelium Leakproof and Separate Its Apical
and Basolateral Surfaces 703
Cytoskeleton-linked Junctions Bind Epithelial Cells Robustly to One Another
and to the Basal Lamina 704
Gap Junctions Allow Cytosolic Inorganic Ions and Small Molecules to Pass from Cell to Cell 707
STEM CELLS AND TISSUE RENEWAL 709
Tissues Are Organized Mixtures of Many Cell Types 710
Different Tissues Are Renewed at Different Rates 711
Stem Cells and Proliferating Precursor Cells Generate a Continuous Supply of Terminally Differentiated Cells 712
Specific Signals Maintain Stem-Cell Populations 714
Stem Cells Can Be Used to Repair Lost or Damaged Tissues 715
Induced Pluripotent Stem Cells Provide a Convenient Source of Human ES-like Cells 716
Mouse and Human Pluripotent Stem Cells Can Form Organoids in Culture 717