Life The Science of Biology

by Purves, William K.; Sadava, David E.; Orians, Gordon H.; Heller, H. Craig

• ISBN13: 9780716798569
• ISBN10: 0716798565
• Edition: 7th
• Format: Hardcover
• Copyright: 2003-12-05
• Publisher: W. H. Freeman

Summary

The guide offers clearly defined learning objectives, summaries of key concepts, references to "Life" and to the student Web/CD-ROM, and review and exam-style self-test questions with answers and explanations.

Table of Contents

An Evolutionary Framework for Biology	1	(14)
What Is Life?	2	(1)
Metabolism involves conversions of matter and energy	2	(1)
Reproduction continues life and provides the basis for evolution	3	(1)
Biological Evolution: Changes over Billions of Years	3	(1)
Darwin provided a mechanistic explanation of biological evolution	4	(1)
Major Events in the History of Life on Earth	4	(2)
Life arose from nonlife via chemical evolution	4	(1)
Biological evolution began when cells formed	4	(1)
Photosynthesis changed the course of evolution	5	(1)
Cells with complex internal compartments arose	6	(1)
Multicellularity arose and cells became specialized	6	(1)
Sex increased the rate of evolution	6	(1)
Levels of Organization of Life	6	(1)
The Evolutionary Tree of Life	7	(3)
Biology Is a Science	10	(5)
Conceptual tools guide scientific research	10	(1)
Hypotheses are tested in two major ways	10	(3)
Not all forms of inquiry are scientific	13	(1)
Biology has implications for public policy	13	(2)
Part One THE CELL
Life and Chemistry: Small Molecules	15	(20)
Water and the Origin of Life's Chemistry	16	(1)
Atoms: The Constituents of Matter	16	(3)
An element is made up of only one kind of atom	17	(1)
The number of protons identifies the element	18	(1)
Isotopes differ in number of neutrons	18	(1)
Electron behavior determines chemical bonding	18	(1)
Chemical Bonds: Linking Atoms Together	19	(6)
Covalent bonds consist of shared pairs of electrons	21	(2)
Hydrogen bonds may form within or between atoms with polar covalent bonds	23	(1)
Ionic bonds form by electrical attraction	23	(1)
Polar and nonpolar substances interact best among themselves	24	(1)
Chemical Reactions: Atoms Change Partners	25	(1)
Water: Structure and Properties	26	(2)
Water has a unique structure and special properties	26	(2)
Water is the solvent of life	28	(1)
Acids, Bases, and the pH Scale	28	(2)
Acids donate H+, bases accept H+	28	(1)
The reactions between acids and bases may be reversible	29	(1)
Water is a weak acid	29	(1)
pH is the measure of hydrogen ion concentration	29	(1)
Buffers minimize pH change	30	(1)
Properties of Molecules	30	(5)
Functional groups give specific properties to molecules	31	(1)
Isomers have different arrangements of the same atoms	32	(3)
Life and Chemistry: Large Molecules	35	(26)
Theories of the Origin of Life	35	(2)
Could life have come from outside Earth?	36	(1)
Did life originate on Earth?	36	(1)
Macromolecules: Giant Polymers	37	(1)
Condensation and Hydrolysis Reactions	38	(1)
Proteins: Polymers of Amino Acids	38	(7)
Proteins are composed of amino acids	39	(1)
Peptide linkages covalently bond amino acids together	40	(1)
The primary structure of a protein is its amino acid sequence	41	(1)
The secondary structure of a protein requires hydrogen bonding	41	(1)
The tertiary structure of a protein is formed by bending and folding	41	(2)
The quaternary structure of a protein consists of subunits	43	(1)
The surfaces of proteins have specific shapes	43	(1)
Protein shapes are sensitive to the environment	44	(1)
Chaperonins help shape proteins	45	(1)
Carbohydrates: Sugars and Sugar Polymers	45	(5)
Monosaccharides are simple sugars	46	(1)
Glycosidic linkages bond monosaccharides together	46	(2)
Polysaccharides serve as energy stores or structural materials	48	(1)
Chemically modified carbohydrates contain other groups	48	(2)
Lipids: Water-Insoluble Molecules	50	(4)
Fats and oils store energy	50	(2)
Phospholipids form the core of biological membranes	52	(1)
Carotenoids and steroids	52	(1)
Some lipids are vitamins	53	(1)
Wax coatings repel water	53	(1)
Nucleic Acids: Informational Macromolecules That Can Be Catalytic	54	(3)
The nucleic acids have characteristic chemical properties	54	(1)
The uniqueness of a nucleic acid resides in its nucleotide sequence	54	(2)
DNA is a guide to evolutionary relationships	56	(1)
RNA may have been the first biological catalyst	57	(1)
Nucleotides have other important roles	57	(1)
All Life from Life	57	(4)
Cells: The Basic Units of Life	61	(26)
The Cell: The Basic Unit of Life	62	(3)
Cells may have come from stable bubbles	62	(1)
Cell size is limited by the surface area-to-volume ratio	62	(1)
Microscopes are needed to visualize cells	63	(2)
Cells are surrounded by a plasma membrane	65	(1)
Cells show two organizational patterns	65	(1)
Prokaryotic Cells	65	(1)
Prokaryotic cells share certain features	65	(1)
Some prokaryotic cells have specialized features	65	(1)
Eukaryotic Cells	66	(4)
Compartmentalization is the key to eukaryotic cell function	67	(1)
Organelles can be studied by microscopy or isolated for chemical analysis	67	(3)
Organelles that Process Information	70	(2)
The nucleus contains most of the cell's DNA	70	(2)
Ribosomes are the sites of protein synthesis	72	(1)
The Endomembrane System	72	(3)
The endoplasmic reticulum is a complex factory	72	(1)
The Golgi apparatus stores, modifies, and packages proteins	73	(1)
Lysosomes contain digestive enzymes	74	(1)
Organelles that Process Energy	75	(3)
Mitochondria are energy transformers	75	(1)
Plastids photosynthesize or store materials	76	(1)
Endosymbiosis may explain the origin of mitochondria and chloroplasts	77	(1)
Other Organelles	78	(1)
Peroxisomes house specialized chemical reactions	78	(1)
Vacuoles are filled with water and soluble substances	79	(1)
The Cytoskeleton	79	(3)
Microfilaments function in support and movement	79	(1)
Intermediate filaments are tough supporting elements	80	(1)
Microtubules are long and hollow	81	(1)
Microtubules power cilia and flagella	81	(1)
Motor proteins move along microtubules	82	(1)
Extracellular Structures	82	(5)
The plant cell wall consists largely of cellulose	83	(1)
Animal cells have elaborate extracellular matrices	83	(4)
Cellular Membranes	87	(19)
Membrane Composition and Structure	87	(4)
Lipids constitute the bulk of a membrane	88	(1)
Membrane proteins are asymmetrically distributed	89	(2)
Membrane carbohydrates are recognition sites	91	(1)
Cell Recognition and Adhesion	91	(3)
Cell recognition and adhesion involve proteins at the cell surface	92	(1)
Specialized cell junctions	93	(1)
Passive Processes of Membrane Transport	94	(4)
The physical nature of diffusion	94	(2)
Simple diffusion takes place through the membrane bilayer	96	(1)
Osmosis is the diffusion of water across membranes	96	(1)
Diffusion may be aided by channel proteins	97	(1)
Carrier proteins aid diffusion by binding substances	98	(1)
Active Transport	98	(2)
Active transport is directional	99	(1)
Primary and secondary active transport rely on different energy sources	99	(1)
Endocytosis and Exocytosis	100	(2)
Macromolecules and particles enter the cell by endocytosis	101	(1)
Receptor-mediated endocytosis is highly specific	101	(1)
Exocytosis moves materials out of the cell	102	(1)
Membranes Are Not Simply Barriers	102	(1)
Membranes Are Dynamic	103	(3)
Energy, Enzymes, and Metabolism	106	(19)
Energy and Energy Conversions	107	(4)
Energy changes are related to changes in matter	107	(1)
The first law: Energy is neither created nor destroyed	108	(1)
The second law: Not all energy can be used, and disorder tends to increase	109	(1)
Chemical reactions release or take up energy	110	(1)
Chemical equilibrium and free energy are related	110	(1)
ATP: Transferring Energy in Cells	111	(2)
ATP hydrolysis releases energy	111	(1)
ATP couples exergonic and endergonic reactions	112	(1)
Enzymes: Biological Catalysts	113	(4)
For a reaction to proceed, an energy barrier must be overcome	113	(1)
Enzymes bind specific reactant molecules	114	(1)
Enzymes lower the energy barrier but do not affect equilibrium	115	(1)
What are the chemical events at active sites of enzymes?	115	(2)
Molecular Structure Determines Enzyme Function	117	(2)
The active site is specific to the substrate	117	(1)
An enzyme changes shape when it binds a substrate	117	(1)
Some enzymes require other molecules in order to operate	117	(1)
Substrate concentration affects reaction rate	118	(1)
Metabolism and the Regulation of Enzymes	119	(6)
Metabolism is organized into pathways	119	(1)
Enzyme activity is subject to regulation by inhibitors	119	(1)
Allosteric enzymes control their activity by changing their shape	120	(1)
Allosteric effects regulate metabolism	121	(1)
Enzymes are affected by their environment	122	(3)
Cellular Pathways that Harvest Chemical Energy	125	(20)
Energy and Electrons from Glucose	125	(3)
Cells trap free energy while metabolizing glucose	126	(1)
Redox reactions transfer electrons and energy	126	(1)
The coenzyme NAD is a key electron carrier in redox reactions	127	(1)
An Overview: Releasing Energy from Glucose	128	(1)
Glycolysis: From Glucose to Pyruvate	128	(3)
The energy-investing reactions of glycolysis require ATP	130	(1)
The energy-harvesting reactions of glycolysis yield NADH+ H+ and ATP	130	(1)
Pyruvate Oxidation	131	(1)
The Citric Acid Cycle	131	(3)
The citric acid cycle produces two CO2 molecules and reduced carriers	131	(3)
The Respiratory Chain: Electrons, Protons, and ATP Production	134	(3)
The respiratory chain transports electrons and releases energy	134	(1)
Proton diffusion is coupled to ATP synthesis	135	(2)
Fermentation: ATP from Glucose, without O2	137	(2)
Some fermenting cells produce lactic acid and some produce alcohol	139	(1)
Contrasting Energy Yields	139	(1)
Relationships between Metabolic Pathways	140	(2)
Catabolism and anabolism involve interconversions using carbon skeletons	140	(1)
Catabolism and anabolism are integrated	141	(1)
Regulating Energy Pathways	142	(3)
Photosynthesis: Energy from the Sun	145	(19)
Identifying Photosynthetic Reactants and Products	146	(1)
The Two Pathways of Photosynthesis: An Overview	147	(7)
Light behaves as both a particle and a wave	147	(1)
Absorbing a photon puts a pigment in an excited state	148	(1)
Absorbed wavelengths correlate with biological activity	149	(1)
Photosynthesis uses energy absorbed by several pigments	149	(1)
Light absorption results in photochemical change	149	(1)
Excited chlorophyll in the reaction center acts as a reducing agent for electron transport	150	(1)
Noncyclic electron transport produces ATP and NADPH	151	(1)
Cyclic electron transport produces ATP but no NADPH	152	(1)
Chemiosmosis is the source of the ATP produced in photophosphorylation	153	(1)
Making Carbohydrate from CO2: The Calvin-Benson Cycle	154	(5)
Isotope labeling experiments revealed the steps of the Calvin-Benson cycle	154	(1)
The Calvin-Benson cycle is made up of three processes	155	(1)
Rubisco catalyzes RuBP reaction with O2 as well as CO2	156	(1)
C4 plants can bypass photorespiration	157	(2)
CAM plants also use PEP carboxylase	159	(1)
Metabolic Pathways in Plants	159	(5)
Life Essay: What is science?	163	(1)
Sal Restivo
Part Two INFORMATION AND HEREDITY
Chromosomes, the Cell Cycle, and Cell Division	164	(23)
Systems of Cell Reproduction	165	(2)
Prokaryotes divide by fission	165	(1)
Eukaryotic cells divide by mitosis or meiosis	166	(1)
Interphase and the Control of Cell Division	167	(2)
Cyclins and other proteins signal events in the cell cycle	168	(1)
Growth factors can stimulate cells to divide	169	(1)
Eukaryotic Chromosomes	169	(2)
Mitosis: Distributing Exact Copies of Genetic Information	171	(3)
The centrosomes determine the plane of cell division	171	(1)
Chromatids become visible and the spindle forms during prophase	171	(1)
Chromosome movements are highly organized	172	(2)
Nuclei re-form during telophase	174	(1)
Cytokinesis: The Division of the Cytoplasm	174	(1)
Reproduction: Asexual and Sexual	175	(2)
Reproduction by mitosis results in genetic constancy	175	(1)
Reproduction by meiosis results in genetic diversity	175	(1)
The number, shapes, and sizes of the metaphase chromosomes constitute the karyotype	176	(1)
Meiosis: A Pair of Nuclear Divisions	177	(5)
The first meiotic division reduces the chromosome number	177	(4)
The second meiotic division separates the chromatids	181	(1)
Meiosis leads to genetic diversity	181	(1)
Meiosis Errors	182	(2)
Aneuploidy can give rise to genetic abnormalities	182	(2)
Polyploids can have difficulty in cell division	184	(1)
Cell Death	184	(3)
Genetics: Mendel and Beyond	187	(26)
The Foundations of Genetics	187	(2)
Plant breeders showed that both parents contribute equally to inheritance	188	(1)
Mendel brought new methods to experiments on inheritance	188	(1)
Mendel's Experiments and the Laws of Inheritance	189	(8)
Mendel devised a careful research plan	189	(1)
Mendel's experiment 1 examined a monohybrid cross	190	(2)
Mendel's first law says that alleles segregate	192	(1)
Mendel verified his hypothesis by performing a test cross	192	(2)
Mendel's second law says that alleles of different genes assort independently	194	(1)
Punnett squares or probability calculations: A choice of methods	195	(1)
Mendel's laws can be observed in human pedigrees	196	(1)
Alleles and Their Interactions	197	(3)
New alleles arise by mutation	198	(1)
Many genes have multiple alleles	198	(1)
Dominance is not always complete	198	(1)
In codominance, both alleles are expressed	199	(1)
Some alleles have multiple phenotypic effects	199	(1)
Gene Interactions	200	(2)
Some genes alter the effects of other genes	200	(1)
Hybrid vigor results from new gene combinations and interactions	200	(1)
The environment affects gene action	201	(1)
Most complex phenotypes are determined by multiple genes and environment	201	(1)
Genes and Chromosomes	202	(3)
Genes on the same chromosome are linked	202	(1)
Genes can be exchanged between chromatids	203	(1)
Geneticists can make maps of chromosomes	203	(2)
Sex Determination and Sex-Linked Inheritance	205	(4)
Sex is determined in different ways in different species	205	(1)
The X and Y chromosomes have different functions	206	(1)
Genes on sex chromosomes are inherited in special ways	207	(1)
Humans display many sex-linked characters	208	(1)
Non-Nuclear Inheritance	209	(4)
DNA and Its Role in Heredity	213	(20)
DNA: The Genetic Material	213	(4)
DNA from one type of bacterium genetically transforms another type	214	(1)
The transforming principle is DNA	215	(1)
Viral replication experiments confirm that DNA is the genetic material	215	(2)
The Structure of DNA	217	(3)
X-ray crystallography provided clues to DNA structure	217	(1)
The chemical composition of DNA was known	217	(1)
Watson and Crick described the double helix	217	(1)
Four key features define DNA structure	218	(2)
The double helical structure of DNA is essential to its function	220	(1)
Determining the DNA Replication Mechanism	220	(2)
Three modes of DNA replication appeared possible	220	(1)
Meselson and Stahl demonstrated that DNA replication is semiconservative	221	(1)
The Molecular Mechanisms of DNA Replication	222	(5)
DNA is threaded through a replication complex	222	(1)
Small, circular DNAs replicate from a single origin	223	(1)
Large, linear DNAs have many origins	223	(1)
DNA polymerases need a primer	224	(1)
Cells contain several different DNA polymerases	224	(1)
The lagging strand is synthesized from Okazaki fragments	225	(1)
Telomeres are not fully replicated	226	(1)
DNA Proofreading and Repair	227	(1)
Proofreading mechanisms ensure that DNA replication is accurate	227	(1)
Mismatch repair mechanisms correct base-pairing errors	227	(1)
Excision repair mechanisms repair chemical damage	228	(1)
Practical Applications of DNA Replication	228	(5)
The polymerase chain reaction makes multiple copies of DNA	229	(2)
The nucleotide sequence of DNA can be determined	231	(2)
From DNA to Protein: Genotype to Phenotype	233	(24)
One Gene, One Polypeptide	233	(3)
DNA, RNA, and the Flow of Information	236	(1)
RNA differs from DNA	236	(1)
Information flows in one direction when genes are expressed	236	(1)
RNA viruses modify the central dogma	237	(1)
Transcription: DNA-Directed RNA Synthesis	237	(2)
Initiation of transcription requires a promoter and RNA polymerase	237	(2)
RNA polymerase elongates the transcript	239	(1)
Transcription terminates at particular base sequences	239	(1)
The Genetic Code	239	(2)
The genetic code is redundant but not ambiguous	240	(1)
The genetic code is (nearly) universal	240	(1)
Biologists deciphered the genetic code by using artificial messengers	240	(1)
Preparation for Translation: Linking RNAs, Amino Acids, and Ribosomes	241	(3)
Transfer RNAs carry specific amino acids and bind to specific codons	241	(1)
Activating enzymes link the right tRNAs and amino acids	242	(1)
The ribosome is the workbench for translation	242	(2)
Translation: RNA-Directed Polypeptide Synthesis	244	(2)
Translation begins with an initiation complex	244	(1)
The polypeptide elongates from the N terminus	244	(1)
Elongation continues and the polypeptide grows	245	(1)
A release factor terminates translation	245	(1)
Regulation of Translation	246	(1)
Some antibiotics and bacterial toxins work by inhibiting translation	246	(1)
Polysome formation increases the rate of protein synthesis	247	(1)
Posttranslational Events	247	(3)
Chemical signals in proteins direct them to their cellular destinations	247	(2)
Many proteins are modified after translation	249	(1)
Mutations: Heritable Changes in Genes	250	(7)
Point mutations are changes in single nucleotides	251	(1)
Chromosomal mutations are extensive changes in the genetic material	252	(1)
Mutations can be spontaneous or induced	253	(1)
Mutations are the raw material of evolution	254	(3)
The Genetics of Viruses and Prokaryotes	257	(22)
Probing the Nature of Genes	258	(1)
Viruses: Reproduction and Recombination	258	(5)
Scientists studied viruses before they could see them	258	(1)
Viruses reproduce only with the help of living cells	258	(1)
There are many kinds of viruses	259	(1)
Bacteriophage reproduce by a lytic cycle or a lysogenic cycle	259	(2)
Lytic bacteriophage could be useful in treating bacterial infections	261	(1)
Animal viruses have diverse reproductive cycles	261	(2)
Many plant viruses spread with the help of vectors	263	(1)
Prokaryotes: Reproduction and Recombination	263	(6)
The reproduction of prokaryotes gives rise to clones	264	(1)
In recombination, bacteria conjugate	264	(2)
In transformation, cells pick up genes from their environment	266	(1)
In transduction, viruses carry genes from one cell to another	266	(1)
Plasmids are extra chromosomes in bacteria	267	(1)
Transposable elements move genes among plasmids and chromosomes	268	(1)
Regulation of Gene Expression in Prokaryotes	269	(4)
Regulation of transcription conserves energy	269	(1)
A single promoter controls the transcription of adjacent genes	270	(1)
Operons are units of transcription in prokaryotes	270	(1)
Operator-repressor control that induces transcription: The lac operon	271	(1)
Operator-repressor control that represses transcription: The trp operon	272	(1)
Protein synthesis can be controlled by increasing promoter efficiency	273	(1)
Control of Transcription in Viruses	273	(2)
Prokaryotic Genomes	275	(4)
Functional genomics relates gene sequences to functions	275	(1)
The sequencing of prokaryotic genomes has medical applications	276	(1)
What genes are required for cellular life?	276	(3)
The Eukaryotic Genome and Its Expression	279	(22)
The Eukaryotic Genome	279	(4)
The eukaryotic genome is larger and more complex than the prokaryotic genome	279	(1)
The yeast genome adds some eukaryotic functions to a prokaryotic model	280	(1)
The nematode genome adds developmental complexity	281	(1)
The fruit fly genome has surprisingly few genes	282	(1)
The puffer fish is a vertebrate with a compact genome	282	(1)
The rice genome reflects that of a model plant, Arabidopsis	282	(1)
Repetitive Sequences in the Eukaryotic Genome	283	(2)
Highly repetitive sequences are present in large numbers of copies	283	(1)
Some moderately repetitive sequences are transcribed	284	(1)
Transposons move about the genome	284	(1)
The Structures of Protein-Coding Genes	285	(3)
Protein-coding genes contain noncoding internal and flanking sequences	285	(1)
Many eukaryotic genes are members of gene families	286	(2)
RNA Processing	288	(2)
The primary transcript of a protein-coding gene is modified at both ends	289	(1)
Splicing removes introns from the primary transcript	289	(1)
Transcriptional Regulation of Gene Expression	290	(6)
Specific genes can be selectively transcribed	290	(3)
Genes can be inactivated by chromatin structure	293	(2)
A DNA sequence can be moved to a new location to activate transcription	295	(1)
Selective gene amplification results in more templates for transcription	295	(1)
Posttranscriptional Regulation	296	(2)
Different mRNAs can be made from the same gene by alternative splicing	296	(1)
The stability of mRNA can be regulated	297	(1)
RNA can be edited to change the encoded protein	297	(1)
Translational and Posttranslational Regulation	298	(3)
The translation of mRNA can be regulated	298	(1)
The proteasome controls the longevity of proteins after translation	298	(3)
Cell Signaling and Communication	301	(16)
Cells receive signals from the physical environment and from other cells	302	(15)
A signal transduction pathway involves a signal, a receptor, transduction, and effects	302	(2)
Receptors have specific binding sites for their signals	304	(1)
There are several types of receptors	305	(2)
Protein kinase cascades amplify a response to receptor binding	307	(2)
Cyclic AMP is a common second messenger	309	(1)
Two second messengers are derived from lipids	310	(1)
Calcium ions are involved in many signal transduction pathways	310	(1)
Nitric oxide is a gas that can act as a second messenger	311	(1)
Signal transduction is highly regulated	311	(1)
Ion channels are opened	312	(1)
Enzyme activities are changed	312	(1)
Different genes are transcribed	313	(1)
Animal cells communicate by gap junctions	314	(1)
Plant cells communicate by plasmodesmata	314	(3)
Recombinant DNA and Biotechnology	317	(22)
Cleaving and Rejoining DNA	318	(3)
Restriction enzymes cleave DNA at specific sequences	318	(1)
Gel electrophoresis identifies the sizes of DNA fragments	319	(1)
Recombinant DNA can be made in the test tube	320	(1)
Getting New Genes into Cells	321	(3)
Genes can be inserted into prokaryotic or eukaryotic cells	321	(1)
Vectors can carry new DNA into host cells	322	(1)
Reporter genes identify host cells containing recombinant DNA	323	(1)
Sources of Genes for Cloning	324	(2)
Gene libraries contain pieces of a genome	324	(1)
A DNA copy of mRNA can be made by reverse transcriptase	325	(1)
DNA can be synthesized chemically in the laboratory	325	(1)
DNA can be mutated in the laboratory	326	(1)
Some Additional Tools for DNA Manipulation	326	(4)
Genes can be inactivated by homologous recombination	326	(1)
DNA chips can reveal DNA mutations and RNA expression	327	(1)
Antisense RNA and RNA interference can prevent the expression of specific genes	328	(1)
The two-hybrid system shows which proteins interact in a cell	329	(1)
Biotechnology: Applications of DNA Manipulation	330	(9)
Expression vectors can turn cells into protein factories	330	(1)
Medically useful proteins can be made by biotechnology	331	(1)
DNA manipulation is changing agriculture	331	(3)
There is public concern about biotechnology	334	(1)
DNA fingerprinting is based on the polymerase chain reaction	335	(4)
Molecular Biology and Medicine	339	(25)
Abnormal or Missing Proteins: The Mutant Phenotype	340	(4)
Dysfunctional enzymes can cause diseases	340	(1)
Abnormal hemoglobin is the cause of sickle-cell disease	341	(1)
Altered membrane proteins cause many diseases	341	(1)
Altered structural proteins can cause disease	342	(1)
Prion diseases are disorders of protein conformation	343	(1)
Most diseases are caused by both genes and environment	343	(1)
Human genetic diseases have several patterns of inheritance	343	(1)
Mutations and Human Diseases	344	(4)
One way to identify a gene is to start with its protein	345	(1)
Chromosome deletions can lead to gene and then protein isolation	345	(1)
Genetic markers can point the way to important genes	346	(1)
Human gene mutations come in many sizes	347	(1)
Expanding triplet repeats demonstrate the fragility of some human genes	347	(1)
Genomic imprinting shows that mammals need both a mother and a father	348	(1)
Detecting Genetic Variations: Screening for Human Diseases	348	(2)
Screening for abnormal phenotypes can make use of protein expression	349	(1)
Several screening methods can find abnormal genes	349	(1)
Cancer: A Disease of Genetic Changes	350	(5)
Cancer cells differ from their normal counterparts	351	(1)
Some cancers are caused by viruses	352	(1)
Most cancers are caused by genetic mutations	352	(1)
Two kinds of genes are changed in many cancers	353	(1)
The pathway from normal cell to cancerous cell is complex	354	(1)
Treating Genetic Diseases	355	(2)
One approach to treatment is to modify the phenotype	355	(1)
Gene therapy offers the hope of specific treatments	356	(1)
Sequencing the Human Genome	357	(7)
There are two approaches to genome sequencing	358	(1)
The sequence of the human genome has been determined	359	(1)
The human genome sequence has many applications	360	(1)
How should genetic information be used?	360	(1)
The proteome is more complex than the genome	361	(3)
Natural Defenses against Disease	364	(26)
Animal Defense Systems	365	(2)
Blood and lymph tissues play important roles in defense systems	365	(1)
White blood cells play many defensive roles	366	(1)
Immune system proteins bind pathogens or signal other cells	367	(1)
Nonspecific Defenses	367	(3)
Barriers and local agents defend the body against invaders	368	(1)
Nonspecific defenses include chemical and cellular processes	368	(2)
A cell signaling pathway stimulates defense	370	(1)
Specific Defenses: The Immune System	370	(4)
Four features characterize the immune system	370	(1)
There are two interactive immune responses	371	(1)
Genetic processes and clonal selection generate the characteristics of the immune response	371	(1)
Immunity and immunological memory result from clonal selection	372	(1)
Vaccines are an application of immunological memory	372	(2)
Animals distinguish self from nonself and tolerate their own antigens	374	(1)
B Cells: The Humoral Immune Response	374	(3)
Some B cells develop into plasma cells	374	(1)
Different antibodies share a common structure	374	(1)
Hybridomas produce monoclonal antibodies	375	(2)
T Cells: The Cellular Immune Response	377	(4)
T cell receptors are found on two types of T cells	378	(1)
The major histocompatibility complex encodes proteins that present antigens to the immune system	378	(1)
Helper T cells and MHC II proteins contribute to the humoral immune response	379	(2)
Cytotoxic T cells and MHC I proteins contribute to the cellular immune response	381	(1)
MHC proteins underlie the tolerance of self	381	(1)
MHC proteins are responsible for transplant rejection	381	(1)
The Genetic Basis of Antibody Diversity	381	(3)
Antibody diversity results from DNA rearrangement and other mutations	382	(1)
The constant region is involved in class switching	383	(1)
Disorders of the Immune System	384	(6)
AIDS is an immune deficiency disorder	384	(1)
HIV infection and replication occur in TH cells	385	(1)
Treatments for HIV infection rely on knowing its molecular biology	386	(3)
Life Essay: What are the ethical issues surrounding genetic modification of nature?	389	(1)
Gary Comstock
Part Three DEVELOPMENT
Differential Gene Expression in Development	390	(18)
The Processes of Development	391	(2)
Development consists of growth, differentiation, and morphogenesis	391	(1)
As development proceeds, cells become more and more specialized	392	(1)
The Role of Differential Gene Expression in Cell Differentiation	393	(4)
With differentiation, there is generally no irreversible change in the genome	393	(3)
Stem cells can be induced to differentiate by environmental signals	396	(1)
Genes are differentially expressed in cell differentiation	396	(1)
The Roles of Cytoplasmic Segregation and Induction in Cell Determination	397	(4)
Polarity results from cytoplasmic segregation	398	(1)
Tissues direct the development of their neighbors by secreting inducers	399	(1)
Single cells can induce changes in their neighbors	399	(2)
The Role of Pattern Formation in Organ Development	401	(2)
Some cells are programmed to die	401	(1)
Plants have organ identity genes	401	(1)
Morphogen gradients provide positional information	402	(1)
The Role of Differential Gene Expression in Establishing Body Segmentation	403	(5)
Maternal effect genes encode morphogens that determine polarity	403	(1)
Segmentation and homeotic genes act after the maternal effect genes	404	(1)
Drosophila development results from a transcriptionally controlled gene cascade	404	(1)
Homeotic mutations produce changes in segment identity	405	(1)
Homeobox-containing genes encode transcription factors	406	(2)
Animal Development: From Genes to Organism	408	(21)
Development Begins with Fertilization	409	(1)
The sperm and the egg make different contributions to the zygote	409	(1)
Fertilization causes rearrangements of egg cytoplasm	409	(1)
Rearrangements of egg cytoplasm set the stage for determination	410	(1)
Cleavage: Repackaging the Cytoplasm	410	(4)
The amount of yolk influences cleavage	411	(1)
The orientation of mitotic spindles influences the pattern of cleavage	411	(1)
Cleavage in mammals is unique	412	(1)
Specific blastomeres generate specific tissues and organs	413	(1)
Gastrulation: Producing the Body Plan	414	(6)
Invagination of the vegetal pole characterizes gastrulation in the sea urchin	414	(1)
Gastrulation in the frog begins at the gray crescent	415	(1)
The dorsal lip of the blastopore organizes embryo formation	416	(3)
Reptilian and avian gastrulation is an adaptation to yolky eggs	419	(1)
Mammals have no yolk, but retain the avian-reptilian gastrulation pattern	420	(1)
Neurulation: Initiating the Nervous System	420	(3)
The stage is set by the dorsal lip of the blastopore	420	(1)
Body segmentation develops during neurulation	421	(1)
Hox genes control development along the anterior-posterior axis	422	(1)
Extraembryonic Membranes	423	(1)
Extraembryonic membranes form with contributions from all germ layers	423	(1)
Extraembryonic membranes in mammals form the placenta	423	(1)
The extraembryonic membranes provide means of detecting genetic diseases	424	(1)
Human Development	424	(5)
Intrauterine development can be divided into three trimesters	424	(2)
Developmental changes continue throughout life	426	(3)
Development and Evolutionary Change	429	(13)
Evolution and Development	430	(2)
Development uses the same sets of genes throughout the animal kingdom	431	(1)
Regulatory Genes and Modularity: Modifying Morphology	432	(2)
Mutations can result in new phenotypes	432	(1)
The timing of a gene's expression can affect morphology	433	(1)
Plant Development and Evolution	434	(1)
Environmental Influences on Developmental Patterns	435	(3)
Organisms respond to signals that accurately predict the future	435	(2)
Some conditions that accurately predict the future may not always occur	437	(1)
Organisms do not respond to environmental signals that are poorly correlated with future conditions	438	(1)
Organisms may lack appropriate responses to new environmental signals	438	(1)
Learning: A Modification of Development	438	(4)
Life Essay: What are the moral issues surrounding stem cell therapy?	441	(1)
Bonnie Steinbock
Part Four EVOLUTIONARY PROCESSES
The History of Life on Earth	442	(18)
Defining Biological Evolution	443	(1)
Determining Earth's Age	443	(2)
Radioactivity provides a way to date rocks	443	(1)
Radioisotope dating methods have been expanded and refined	444	(1)
The Changing Face of Earth	445	(3)
The continents have changed their positions	445	(1)
Earth's atmosphere has changed unidirectionally	445	(2)
Earth's climate shifts between hot/humid and cold/dry conditions	447	(1)
Volcanoes occasionally changed the history of life	447	(1)
External events have triggered changes on Earth	448	(1)
The Fossil Record	448	(1)
Major Patterns in the History of Life on Earth	449	(6)
Life expanded rapidly during the Cambrian period	449	(1)
Major changes continued during the rest of the Paleozoic era	450	(2)
Geographic differentiation increased during the Mesozoic era	452	(2)
The modern biota evolved during the Cenozoic era	454	(1)
Three major faunas have dominated life on Earth	454	(1)
Rates of Evolutionary Change within Lineages	455	(3)
Some living species closely resemble ancient ancestors	455	(1)
Evolutionary changes have been gradual in some lineages	456	(1)
Rates of evolutionary change are sometimes rapid	456	(1)
Extinction rates vary over time	457	(1)
The Future of Evolution	458	(2)
The Mechanisms of Evolution	460	(21)
Charles Darwin's Theory of Evolution	461	(2)
Genetic Variation within Populations	463	(3)
Most populations are genetically variable	464	(1)
How do we measure genetic variation?	465	(1)
The Hardy-Weinberg Equilibrium	466	(1)
Why is the Hardy-Weinberg equilibrium important?	467	(1)
Evolutionary Agents and Their Effects	467	(3)
Mutations are changes in the genetic material	467	(1)
Movement of individuals or gametes, followed by reproduction, produces gene flow	468	(1)
Genetic drift may cause large changes in small populations	468	(1)
Nonrandom mating changes the frequency of homozygotes	469	(1)
Natural selection results in adaptation	470	(1)
The Results of Natural Selection	470	(4)
Sexual selection results in conspicuous traits	473	(1)
Assessing the Costs of Adaptations	474	(1)
Maintaining Genetic Variation	475	(2)
Sexual recombination amplifies the number of possible genotypes	475	(1)
Neutral mutations accumulate within species	476	(1)
Frequency-dependent selection maintains genetic variation within populations	476	(1)
Genetic variation is maintained in geographically distinct subpopulations	476	(1)
Constraints on Evolution	477	(1)
Cultural Evolution	478	(1)
Short-Term versus Long-Term Evolution	478	(3)
Species and Their Formation	481	(15)
What Are Species?	482	(1)
How Do New Species Arise?	483	(4)
Allopatric speciation requires total genetic isolation	483	(3)
Sympatric speciation occurs without physical barriers	486	(1)
Completing Speciation: Reproductive Isolating Mechanisms	487	(3)
Prezygotic barriers operate before fertilization	488	(1)
Postzygotic barriers operate after fertilization	489	(1)
We can observe speciation in progress	489	(1)
Hybrid Zones: Incomplete Reproductive Isolation	490	(2)
Variation in Speciation Rates	492	(1)
Evolutionary Radiations	492	(4)
Reconstructing and Using Phylogenies	496	(14)
Phylogenetic Trees	497	(2)
Homologous traits are inherited from a common ancestor	498	(1)
Identifying ancestral traits is sometimes difficult	498	(1)
Steps in Reconstructing Phylogenies	499	(1)
Morphological and developmental traits are used in reconstructing phylogenies	499	(1)
Molecular traits are also useful in reconstructing phylogenies	500	(1)
Reconstructing a Simple Phylogeny	500	(3)
Systematists use the parsimony principle when reconstructing phylogenies	502	(1)
Biological Classification and Evolutionary Relationships	503	(2)
Current biological classifications reflect evolutionary relationships	504	(1)
Phylogenetic Trees Have Many Uses	505	(5)
How many times has a trait evolved?	505	(1)
When did lineages split?	506	(1)
How recently did Lake Victoria's cichlid fishes radiate?	506	(4)
Molecular and Genomic Evolution	510	(14)
Genomes and Their Evolution	511	(1)
The Evolution of Macromolecules	511	(1)
Molecular evolution is driven by changes in nucleotide sequences	511	(1)
Many mutations may be selectively neutral	512	(1)
Determining and Comparing the Structure of Macromolecules	512	(4)
Rates of nucleotide substitution vary because the roles of molecules differ	513	(1)
Changes in macromolecules can serve as molecular clocks	514	(2)
Proteins Acquire New Functions	516	(1)
Proteins may acquire new functions via gene duplication	516	(1)
Physiological changes may lead to the evolution of new functions for a protein	516	(1)
The Evolution of Genome Size	517	(2)
Complex organisms have more DNA than do simpler ones	517	(1)
Gene duplication can increase genome size and complexity	518	(1)
The Uses of Molecular Genomic Information	519	(5)
Molecular information is used to reconstruct phylogenies	519	(1)
Molecular data are used to determine the phylogenetic histories of genes	520	(1)
Molecular information provides new ways to combat diseases	520	(1)
Molecular data cannot solve all disease problems	521	(2)
Life Essay: How has Darwin's theory of natural selection transformed our view of humanity's place in the universe?	523	(1)
Daniel Dennett
Part Five THE EVOLUTION OF DIVERSITY
Bacteria and Archaea: The Prokaryotic Domains	524	(19)
Why Three Domains?	525	(1)
General Biology of the Prokaryotes	526	(5)
Prokaryotes and their associations take a few characteristic forms	527	(1)
Prokaryotes lack nuclei, organelles, and a cytoskeleton	527	(1)
Prokaryotes have distinctive modes of locomotion	527	(1)
Prokaryotes have distinctive cell walls	528	(1)
Prokaryotes reproduce asexually, but genetic recombination does occur	529	(1)
Prokaryotes have exploited many metabolic possibilities	529	(2)
Prokaryotes in Their Environments	531	(2)
Prokaryotes are important players in element cycling	531	(1)
Archaea help stave off global warming	531	(1)
Prokaryotes live on and in other organisms	532	(1)
A small minority of bacteria are pathogens	532	(1)
Prokaryotes may form biofilms	533	(1)
Prokaryote Phylogeny and Diversity	533	(1)
The nucleotide sequences of prokaryotes reveal their evolutionary relationships	533	(1)
Lateral gene transfer muddied the phylogenetic waters	534	(1)
Mutations are a major source of prokaryotic variation	534	(1)
The Bacteria	534	(5)
Some bacteria are heat lovers	535	(1)
The Proteobacteria are a large and diverse group	535	(1)
Cyanobacteria are important photoautotrophs	536	(1)
Spirochetes look like corkscrews	536	(1)
Chlamydias are extremely small	537	(1)
Most firmicutes are Gram-positive	537	(2)
The Archaea	539	(4)
The Archaea share some unique characteristics	539	(1)
Most Crenarchaeota live in hot, acidic places	539	(1)
The Euryarchaeota live in many surprising places	540	(3)
Protists and the Dawn of the Eukarya	543	(27)
Protists Defined	543	(1)
The Origin of the Eukaryotic Cell	544	(2)
The modern eukaryotic cell arose in several steps	544	(2)
Many uncertainties remain	546	(1)
General Biology of the Protists	546	(3)
Protists have diverse means of locomotion	546	(1)
Vesicles perform a variety of functions	546	(1)
The cell surfaces of protists are diverse	547	(1)
Many protists contain endosymbionts	548	(1)
Both asexual and sexual reproduction occur among the protists	548	(1)
Protist Diversity	549	(1)
Diplomonads and Parabasalids	549	(2)
Euglenozoans	551	(1)
Euglenoids have anterior flagella	551	(1)
Kinetoplastids have mitochondria that edit their own RNA	551	(1)
Alveolates	552	(4)
Dinoflagellates are unicellular marine organisms with two flagella	552	(1)
Apicomplexans are parasites with unusual spores	552	(2)
Ciliates have two types of nuclei	554	(2)
Stramenopiles	556	(4)
Diatoms are everywhere in the marine environment	556	(1)
The brown algae include the largest protists	557	(1)
Many protist and all plant life cycles feature alternation of generations	558	(1)
The oomycetes include water molds and their relatives	559	(1)
Red Algae	560	(1)
Chlorophytes	560	(2)
Chlorophytes vary in shape and cellular organization	561	(1)
Chlorophyte life cycles are diverse	561	(1)
There are green algae other than chlorophytes	562	(1)
Choanoflagellates	562	(1)
A History of Endosymbiosis	563	(1)
Some Recurrent Body Forms	564	(6)
Amoebas form pseudopods	564	(1)
Slime molds release spores from erect fruiting bodies	565	(5)
Plants without Seeds: From Sea to Land	570	(18)
The Plant Kingdom	571	(2)
There are ten surviving phyla of plants	571	(1)
Life cycles of plants feature alternation of generations	571	(1)
The Plantae arose from a green algal clade	572	(1)
The Conquest of the Land	573	(1)
Adaptations to life on land distinguish plants from green algae	573	(1)
Most present-day plants have vascular tissues	573	(1)
The Nontracheophytes: Liverworts, Hornworts, and Mosses	574	(4)
Nontracheophyte sporophytes are dependent on gametophytes	575	(1)
Liverworts may be the most ancient surviving plant clade	576	(1)
Hornworts evolved stomata as an adaptation to terrestrial life	576	(1)
Water and sugar transport mechanisms emerged in the mosses	577	(1)
Introducing the Tracheophytes	578	(5)
Tracheophytes have been evolving for almost half a billion years	579	(1)
The earliest tracheophytes lacked roots and leaves	579	(2)
Early tracheophytes added new features	581	(2)
The Surviving Nonseed Tracheophytes	583	(5)
The club mosses are sister to the other tracheophytes	583	(1)
Horsetails, whisk ferns, and ferns constitute a clade	583	(1)
Ferns evolved large, complex leaves	584	(1)
The sporophyte generation dominates the fern life cycle	585	(3)
The Evolution of Seed Plants	588	(15)
The Seed Plants	588	(2)
Seed plants are heterosporous and have tiny gametophytes	589	(1)
The seed is a complex package	590	(1)
The Gymnosperms: Naked Seeds	590	(3)
Conifers have cones but no motile cells	592	(1)
The Angiosperms: Flowering Plants	593	(10)
The sexual structures of angiosperms are flowers	594	(1)
Flower structure has evolved over time	595	(1)
Angiosperms have coevolved with animals	596	(1)
The angiosperm life cycle features double fertilization	597	(1)
Angiosperms produce fruits	598	(1)
There are several clades of angiosperms	598	(3)
Determining the oldest angiosperm clade	601	(1)
The origin of the angiosperms remains a mystery	601	(2)
Fungi: Recyclers, Pathogens, Parasites, and Plant Partners	603	(16)
General Biology of the Fungi	604	(4)
Some fungi are unicellular	604	(1)
The body of a multicellular fungus is composed of hyphae	604	(2)
Fungi are in intimate contact with their environment	606	(1)
Fungi are absorptive heterotrophs	606	(1)
Most fungi reproduce both asexually and sexually	607	(1)
The presence of a dikaryon is a synapomorphy of three phyla	607	(1)
Some fungi are pathogens	607	(1)
Diversity in the Kingdom Fungi	608	(7)
Chytrids probably resemble the ancestral fungi	608	(1)
Zygomycetes reproduce sexually by fusion of two gametangia	609	(1)
The sexual reproductive structure of ascomycetes is an ascus	609	(3)
The sexual reproductive structure of basidiomycetes is a basidium	612	(2)
Imperfect fungi lack a sexual stage	614	(1)
Fungal Associations	615	(4)
Mycorrhizae are essential to many plants	615	(1)
Lichens can grow where plants cannot	616	(3)
Animal Origins and the Evolution of Body Plans	619	(22)
Animals: Descendants of a Common Ancestor	620	(1)
Animals are multicellular heterotrophs	620	(1)
Several traits show evolutionary relationships among animals	620	(1)
Body Plans: Basic Structural Designs	621	(1)
Sponges: Loosely Organized Animals	622	(2)
Cnidarians: Two Cell Layers and Blind Guts	624	(3)
Cnidarians are simple but specialized carnivores	624	(1)
Cnidarian life cycles have two stages	625	(2)
Ctenophores: Complete Guts and Tentacles	627	(1)
The Evolution of Bilaterally Symmetrical Animals	628	(1)
An early lineage split separated protostomes and deuterostomes	628	(1)
The protostomes split into two lineages	629	(1)
Simple Lophotrochozoans	629	(2)
Flatworms move by beating cilia	629	(2)
Rotifers are small but structurally complex	631	(1)
Lophophorates: An Ancient Body Plan	631	(2)
Phoronids are sedentary lophophorates	632	(1)
Ectoprocts are colonial lophophorates	632	(1)
Brachiopods superficially resemble bivalve mollusks	632	(1)
Spiralians: Spiral Cleavage and Wormlike Body Plans	633	(8)
Ribbon worms are unsegmented	633	(1)
Segmentation improved locomotion in the annelids	634	(2)
Mollusks evolved shells	636	(5)
Ecdysozoans: The Molting Animals	641	(14)
Cuticles: Flexible, Unsegmented Exoskeletons	641	(3)
Some marine ecdysozoan phyla have few species	642	(1)
Tough cuticles evolved in some unsegmented worms	643	(1)
Arthropods and Their Relatives: Segmented External Skeletons	644	(2)
Some relatives of the arthropods have unjointed legs	645	(1)
Jointed legs appeared in the trilobites	645	(1)
Modern arthropods dominate Earth's fauna	645	(1)
Crustaceans: Diverse and Abundant	646	(1)
Insects: Terrestrial Descendants of Marine Crustaceans	647	(3)
Arthropods with Two Body Regions	650	(2)
Myriapods have many legs	650	(1)
Most chelicerates have four pairs of walking legs	650	(2)
Themes in the Evolution of Protostomes	652	(3)
Deuterostomate Animals	655	(27)
Deuterostome Ancestors	655	(1)
Echinoderms: Pentaradial Symmetry	656	(4)
Pelmatozoans have jointed arms	657	(1)
Eleutherozoans are the dominant echinoderms	657	(3)
Hemichordates: Conservative Evolution	660	(1)
Chordates: New Ways of Feeding	660	(6)
A jointed vertebral column replaced the notochord in vertebrates	661	(2)
Jaws improved feeding efficiency	663	(1)
Fins improved mobility	664	(1)
Swim bladders allowed control of buoyancy	664	(2)
Colonizing the Land: Obtaining Oxygen from the Air	666	(4)
Amphibians invaded the land	666	(1)
Amniotes colonized dry environments	667	(1)
Reptilian lineages diverged	668	(2)
Birds: More Feathers and Better Flight	670	(2)
The Origin and Diversity of Mammals	672	(1)
Primates and the Origin of Humans	673	(5)
Human ancestors evolved bipedal locomotion	676	(1)
Humans arose from australopithecine ancestors	676	(1)
Human brains became larger	677	(1)
Humans evolved language and culture	678	(1)
Deuterostomes and Protostomes: Shared Evolutionary Themes	678	(4)
Life Essay: What is our duty to nature?	681	(1)
Holmes Rolston, III
Part Six THE BIOLOGY OF FLOWERING PLANTS
The Plant Body	682	(19)
Vegetative Organs of the Flowering Plant Body	683	(3)
Roots anchor the plant and take up water and minerals	683	(1)
Stems bear buds, leaves, and flowers	684	(1)
Leaves are the primary sites of photosynthesis	685	(1)
Plant Cells	686	(4)
Cell walls may be complex in structure	686	(1)
Parenchyma cells are alive when they perform their functions	687	(2)
Collenchyma cells provide flexible support while alive	689	(1)
Sclerenchyma cells provide rigid support	689	(1)
Xylem transports water from roots to stems and leaves	689	(1)
Phloem translocates carbohydrates and other nutrients	689	(1)
Plant Tissues and Tissue Systems	690	(1)
Forming the Plant Body	691	(7)
Plants and animals grow differently	691	(1)
A hierarchy of meristems generates a plant's body	691	(2)
The root apical meristem gives rise to the root cap and the primary meristems	693	(1)
The products of the root's primary meristems become root tissues	694	(1)
The products of the stem's primary meristems become stem tissues	695	(1)
Many stems and roots undergo secondary growth	696	(2)
Leaf Anatomy Supports Photosynthesis	698	(3)
Transport in Plants	701	(15)
Uptake and Movement of Water and Solutes	702	(4)
Water moves through a membrane by osmosis	702	(1)
Aquaporins facilitate the movement of water across membranes	703	(1)
Uptake of mineral ions requires membrane transport proteins	703	(1)
Water and ions pass to the xylem by way of the apoplast and symplast	704	(2)
Transport of Water and Minerals in the Xylem	706	(3)
Experiments ruled out xylem transport by pumping action of living cells	706	(1)
Root pressure does not account for xylem transport	706	(1)
The transpiration-cohesion-tension mechanism accounts for xylem transport	707	(1)
A pressure bomb measures tension in the xylem sap	708	(1)
Transpiration and the Stomata	709	(1)
The guard cells control the size of the stomatal opening	710	(1)
Transpiration from crops can be decreased	710	(1)
Translocation of Substances in the Phloem	710	(6)
The pressure flow model appears to account for translocation in the phloem	712	(1)
The pressure flow model has been experimentally tested	712	(1)
Plasmodesmata and material transfer between cells	713	(3)
Plant Nutrition	716	(13)
The Acquisition of Nutrients	716	(1)
Autotrophs make their own organic compounds	717	(1)
How does a stationary organism find nutrients?	717	(1)
Mineral Nutrients Essential to Plants	717	(2)
Deficiency symptoms reveal inadequate nutrition	718	(1)
Several essential elements fulfill multiple roles	719	(1)
Experiments were designed to identify essential elements	719	(1)
Soils and Plants	719	(3)
Soils are complex in structure	720	(1)
Soils form through the weathering of rock	721	(1)
Soils are the source of plant nutrition	721	(1)
Fertilizers and lime are used in agriculture	721	(1)
Plants affect soil fertility and pH	722	(1)
Nitrogen Fixation	722	(4)
Nitrogen fixers make all other life possible	723	(1)
Nitrogenase catalyzes nitrogen fixation	723	(1)
Some plants and bacteria work together to fix nitrogen	724	(1)
Biological nitrogen fixation does not always meet agricultural needs	725	(1)
Plants and bacteria participate in the global nitrogen cycle	725	(1)
Carnivorous and Heterotrophic Plants	726	(3)
Regulation of Plant Growth	729	(20)
Interacting Factors in Plant Development	730	(1)
Several hormones and photoreceptors regulate plant growth	730	(1)
Signal transduction pathways mediate hormone and photoreceptor action	730	(1)
An Overview of Plant Development	730	(2)
The seed germinates and forms a growing seedling	731	(1)
The plant flowers and sets fruit	731	(1)
The plant senesces and dies	732	(1)
Ending Seed Dormancy and Beginning Germination	732	(1)
Seed dormancy affords adaptive advantages	732	(1)
Seed germination begins with the uptake of water	733	(1)
The embryo must mobilize its reserves	733	(1)
Gibberellins: Regulators from Germination to Fruit Growth	733	(2)
Foolish seedlings led to the discovery of the gibberellins	734	(1)
The gibberellins have many effects	735	(1)
Auxin Affects Plant Growth and Form	735	(7)
Phototropism led to the discovery of auxin	736	(1)
Auxin transport is polar	737	(1)
Carrier proteins move auxin into and out of cells	737	(1)
Light and gravity affect the direction of plant growth	738	(1)
Auxin affects plant growth in several ways	738	(1)
Auxin analogs as herbicides	739	(1)
Auxin promotes growth by acting on cell walls	740	(1)
Plants contain specific auxin receptor proteins	741	(1)
Auxin and other hormones evoke cell differentiation and organ formation	741	(1)
Cytokinins Are Active from Seed to Senescence	742	(1)
Ethylene: A Hormone that Hastens Leaf Senescence and Fruit Ripening	742	(1)
Ethylene hastens the ripening of fruit	742	(1)
Ethylene affects stems in several ways	742	(1)
The ethylene signal transduction pathway is well understood	743	(1)
Abscisic Acid: The Stress Hormone	743	(1)
Brassinosteroids: Hormones that Mediate Effects of Light	744	(1)
Light and Photoreceptors	744	(5)
Phytochromes mediate the effects of red and far-red light	745	(1)
Phytochromes have many effects on plant growth and development	745	(1)
There are multiple phytochromes with different developmental roles	746	(1)
Cryptochromes, phototropins, and zeaxanthin are blue-light receptors	746	(3)
Reproduction in Flowering Plants	749	(16)
Many Ways to Reproduce	749	(1)
Sexual Reproduction in Plants	750	(5)
The flower is an angiosperm's device for sexual reproduction	750	(1)
Flowering plants have microscopic gametophytes	750	(2)
Pollination enables fertilization in the absence of liquid water	752	(1)
Some plants practice ``mate selection''	752	(1)
A pollen tube delivers male cells to the embryo sac	752	(1)
Angiosperms perform double fertilization	753	(1)
Embryos develop within seeds	754	(1)
Some fruits assist in seed dispersal	755	(1)
The Transition to the Flowering State	755	(1)
Apical meristems can become inflorescence meristems	755	(1)
A cascade of gene expression leads to flowering	756	(1)
Photoperiodic Control of Flowering	756	(5)
There are short-day, long-day, and day-neutral plants	756	(1)
The length of the night determines whether a photoperiodic plant will flower	757	(1)
Circadian rhythms are maintained by a biological clock	758	(1)
Photoreceptors set the biological clock	759	(1)
Is there a flowering hormone?	759	(2)
Vernalization and Flowering	761	(1)
Asexual Reproduction	761	(4)
There are many forms of asexual reproduction	761	(1)
Asexual reproduction is important in agriculture	762	(3)
Plant Responses to Environmental Challenges	765	(15)
Plant-Pathogen Interactions	765	(4)
Plants seal off infected parts to limit damage	766	(1)
Plants have potent chemical defenses against pathogens	766	(1)
The hypersensitive response is a localized containment strategy	767	(1)
Systemic acquired resistance is a form of long-term ``immunity''	767	(1)
Some plant genes match up with pathogen genes	768	(1)
Plants develop specific immunity to RNA viruses	768	(1)
Plants and Herbivores: Benefits and Losses	769	(3)
Grazing increases the productivity of some plants	769	(1)
Some plants produce chemical defenses	769	(1)
Some secondary metabolites play multiple roles	770	(1)
Many defenses depend on extensive signaling	770	(1)
Recombinant DNA technology may confer resistance to insects	771	(1)
Why don't plants poison themselves?	771	(1)
The plant doesn't always win	772	(1)
Water Extremes: Dry Soils and Saturated Soils	772	(2)
Some plants evade drought	772	(1)
Some leaves have special adaptations to dry environments	772	(1)
Plants have other adaptations to a limited water supply	773	(1)
In water-saturated soils, oxygen is scarce	774	(1)
Too Much Salt: Saline Environments	774	(2)
Most halophytes accumulate salt	775	(1)
Halophytes and xerophytes have some similar adaptations	775	(1)
Habitats Laden with Heavy Metals	776	(1)
Hot and Cold Environments	776	(4)
Plants have ways of coping with high temperatures	777	(1)
Some plants are adapted to survival at low temperatures	777	(2)
Life Essay: How should we manage fire in the forest?	779	(1)
David E. Pesonen
Part Seven THE BIOLOGY OF ANIMALS
Physiology, Homeostasis, and Temperature Regulation	780	(19)
Homeostasis: Maintaining the Internal Environment	781	(1)
Tissues, Organs, and Organ Systems	782	(3)
Epithelial tissues cover the body and line organs	782	(1)
Connective tissues support and reinforce other tissues	783	(1)
Muscle tissues contract	783	(1)
Nervous tissues process information	784	(1)
Organs consist of multiple tissues	784	(1)
Physiological Regulation and Homeostasis	785	(1)
Temperature and Life	786	(1)
Q10 is a measure of temperature sensitivity	786	(1)
An animal's sensitivity to temperature can change	786	(1)
Maintaining Optimal Body Temperature	787	(5)
Ectotherms and endotherms respond differently to changes in environmental temperature	787	(1)
Ectotherms and endotherms use behavior to regulate body temperature	788	(1)
Energy budgets reflect all physiological adaptations for regulating body temperature	789	(1)
Both ectotherms and endotherms control blood flow to the skin	790	(1)
Some ectotherms produce heat	790	(1)
Some fish elevate body temperature by conserving metabolic heat	791	(1)
Thermoregulation in Endotherms	792	(2)
Basal metabolic rates of endotherms are related to body size	792	(1)
Endotherms respond to cold by producing heat	792	(1)
Decreasing heat loss is important for life in the cold	793	(1)
Evaporation of water is an effective way to lose heat	793	(1)
The Vertebrate Thermostat	794	(5)
The vertebrate thermostat uses feedback information	794	(1)
Fevers help the body fight infections	795	(1)
Turning down the thermostat saves energy	796	(3)
Animal Hormones	799	(21)
Hormones and Their Actions	800	(2)
Hormones can be divided into three chemical groups	800	(1)
Hormone receptors are found on the cell surface or in the cell interior	800	(1)
Some hormones act locally	800	(1)
Most hormones are distributed in the blood	801	(1)
Endocrine glands secrete hormones	801	(1)
Hormonal Control of Molting and Development in Insects	802	(2)
Hormones from the head control molting in insects	802	(1)
Juvenile hormone controls development in insects	803	(1)
Vertebrate Endocrine Systems	804	(11)
The pituitary is closely associated with the brain	805	(3)
Negative feedback loops control hormone secretion	808	(1)
Thyroxine controls cell metabolism	809	(1)
Thyroid dysfunction causes goiter	809	(1)
Calcitonin reduces blood calcium	810	(1)
Parathyroid hormone elevates blood calcium	811	(1)
Vitamin D is really a hormone	811	(1)
PTH lowers blood phosphate levels	811	(1)
Insulin and glucagon regulate blood glucose levels	811	(1)
Somatostatin is a hormone of the brain and the gut	812	(1)
The adrenal gland is two glands in one	812	(2)
The sex steroids are produced by the gonads	814	(1)
Changes in control of sex steroid production initiate puberty	814	(1)
Melatonin is involved in biological rhythms and photo-periodicity	815	(1)
The list of hormones is long	815	(1)
Hormone Actions: The Role of Signal Transduction Pathways	815	(5)
Regulation of hormone receptors controls the sensitivity of cells to hormones	816	(1)
Responses to hormones can vary greatly	816	(4)
Animal Reproduction	820	(24)
Asexual Reproduction	821	(1)
Budding and regeneration produce new individuals by mitosis	821	(1)
Parthenogenesis is the development of unfertilized eggs	821	(1)
Sexual Reproduction	822	(7)
Eggs and sperm form through gametogenesis	822	(2)
Fertilization is the union of sperm and egg	824	(2)
Anatomical and behavioral adaptations bring eggs and sperm together	826	(1)
A single body can function as both male and female	827	(1)
The evolution of vertebrate reproductive systems parallels the move to land	827	(1)
Reproductive systems are distinguished by where the embryo develops	828	(1)
The Human Reproductive System	829	(7)
Male sex organs produce and deliver semen	829	(2)
Male sexual function is controlled by hormones	831	(1)
Female sex organs produce eggs, receive sperm, and nurture the embryo	832	(1)
The ovarian cycle produces a mature egg	833	(1)
The uterine cycle prepares an environment for the fertilized egg	834	(1)
Hormones control and coordinate the ovarian and uterine cycles	834	(1)
In pregnancy, hormones from the extraembryonic membranes take over	835	(1)
Childbirth is triggered by hormonal and mechanical stimuli	835	(1)
Human Sexual Behavior	836	(8)
Human sexual responses consist of four phases	836	(1)
Humans use a variety of technologies to control fertility	837	(2)
Reproductive technologies help solve problems of infertility	839	(2)
Sexual behavior transmits many disease organisms	841	(3)
Neurons and Nervous Systems	844	(21)
Nervous Systems: Cells and Functions	844	(3)
Nervous systems process information	845	(1)
Neurons are the functional units of nervous systems	845	(1)
Glial cells are also important components of nervous systems	846	(1)
Neurons function in networks	847	(1)
Neurons: Generating and Conducting Nerve Impulses	847	(8)
Simple electrical concepts underlie neuronal function	847	(1)
Ion pumps and channels generate resting and action potentials	848	(2)
Ion channels can alter membrane potential	850	(1)
Sudden changes in ion channels generate action potentials	850	(2)
Action potentials are conducted down axons without loss of signal	852	(2)
Ion channels and their properties can be studied directly	854	(1)
Action potentials can jump down axons	854	(1)
Neurons, Synapses, and Communication	855	(10)
The neuromuscular junction is a classic chemical synapse	856	(1)
The arrival of a nerve impulse causes the release of neuro-transmitter	857	(1)
The postsynaptic membrane integrates synaptic input	857	(1)
Synapses between neurons can be excitatory or inhibitory	857	(1)
The postsynaptic cell sums excitatory and inhibitory input	858	(1)
There are two types of neurotransmitter receptors	859	(1)
Electrical synapses are fast but do not integrate information well	859	(1)
The action of a neurotransmitter depends on the receptor to which it binds	859	(2)
Glutamate receptors may be involved in learning and memory	861	(1)
To turn off responses, synapses must be cleared of neuro-transmitter	862	(3)
Sensory Systems	865	(20)
Sensory Cells and Transduction of Stimuli	865	(2)
Sensation depends on which neurons receive action potentials from sensory cells	866	(1)
Sensory transduction involves changes in membrane potentials	866	(1)
Many receptors adapt to repeated stimulation	867	(1)
Chemoreceptors: Responding to Specific Molecules	867	(3)
Arthropods provide good examples for studying chemoreception	867	(1)
Olfaction is the sense of smell	868	(1)
The vomeronasal organ senses pheromones	869	(1)
Gustation is the sense of taste	869	(1)
Mechanoreceptors: Detecting Stimuli that Distort Membranes	870	(5)
Many different sensory cells respond to touch and pressure	870	(1)
Stretch receptors are found in muscles, tendons, and ligaments	871	(1)
Hair cells provide information about balance, orientation in space, and motion	871	(2)
Auditory systems use hair cells to sense sound waves	873	(2)
Photoreceptors and Visual Systems: Responding to Light	875	(7)
Rhodopsins are responsible for photosensitivity	875	(1)
Invertebrates have a variety of visual systems	876	(2)
Image-forming eyes evolved independently in vertebrates and cephalopods	878	(1)
The vertebrate retina receives and processes visual information	878	(4)
Sensory Worlds Beyond Human Experience	882	(3)
The Mammalian Nervous System: Structure and Higher Functions	885	(18)
The Nervous System: Structure, Function, and Information Flow	886	(1)
A conceptual diagram of the nervous system traces information flow	886	(1)
The vertebrate CNS develops from the embryonic neural tube	886	(1)
Functional Subsystems of the Nervous System	887	(5)
The spinal cord receives and processes information from the body	887	(1)
The reticular system alerts the forebrain	888	(1)
The limbic system supports basic functions of the forebrain	889	(1)
Regions of the cerebrum interact to produce consciousness and control behavior	889	(3)
The cerebrum has increased in size and complexity	892	(1)
Information Processing by Neuronal Networks	892	(4)
The autonomic nervous system controls the physiological functions of organs and organ systems	892	(2)
Neurons and circuits in the occipital cortex integrate visual information	894	(1)
Cortical cells receive input from both eyes	895	(1)
Understanding Higher Brain Functions in Cellular Terms	896	(7)
Sleep and dreaming produce electrical patterns in the cerebrum	896	(2)
Some learning and memory can be localized to specific brain areas	898	(1)
Language abilities are localized in the left cerebral hemisphere	899	(1)
What is consciousness?	900	(3)
Effectors: Making Animals Move	903	(19)
Microtubules, Microfilaments, and Cell Movement	903	(1)
Microtubules are components of the cytoskeleton	903	(1)
Microfilaments change cell shape and cause cell movements	904	(1)
Muscle Contraction	904	(7)
Smooth muscle causes slow contractions of many internal organs	905	(1)
Cardiac muscle causes the heart to beat	905	(1)
Sliding filaments cause skeletal muscle to contract	906	(2)
Actin-myosin interactions cause filaments to slide	908	(1)
Actin-myosin interactions are controlled by calcium ions	908	(2)
Calmodulin mediates Ca2+ control of contraction in smooth muscle	910	(1)
Single skeletal muscle twitches are summed into graded contractions	910	(1)
Muscle Strength and Performance	911	(3)
Muscle fiber types determine endurance and strength	911	(1)
The strength of a muscle fiber is related to its length	912	(1)
Exercise increases muscle strength and endurance	912	(1)
Muscle fuel supply limits performance	913	(1)
Skeletal Systems	914	(4)
A hydrostatic skeleton consists of fluid in a muscular cavity	914	(1)
Exoskeletons are rigid outer structures	914	(1)
Vertebrate endoskeletons provide supports for muscles	915	(1)
Bones develop from connective tissues	916	(1)
Bones that have a common joint can work as a lever	917	(1)
Other Effectors	918	(4)
Gas Exchange in Animals	922	(18)
Physical Processes of Respiratory Gas Exchange	923	(2)
Air is a better respiratory medium than water	923	(1)
High temperatures create respiratory problems for aquatic animals	924	(1)
O2 availability decreases with altitude	924	(1)
Carbon dioxide is lost by diffusion	924	(1)
Fick's law applies to all systems of gas exchange	924	(1)
Adaptations for Respiratory Gas Exchange	925	(5)
Respiratory organs have large surface areas	925	(1)
Transporting gases to and from the exchange surfaces optimizes partial pressure gradients	925	(5)
Gas Exchange in Human Lungs	930	(2)
Respiratory tract secretions aid ventilation	930	(1)
Lungs are ventilated by pressure changes in the thoracic cavity	931	(1)
Blood Transport of Respiratory Gases	932	(4)
Hemoglobin combines reversibly with oxygen	933	(1)
Myoglobin holds an O2 reserve	934	(1)
The affinity of hemoglobin for O2 is variable	934	(1)
CO2 is transported as bicarbonate ions in the blood	935	(1)
Regulation of Breathing	936	(4)
Breathing is controlled in the brain stem	936	(1)
Regulating breathing requires feedback information	936	(4)
Circulatory Systems	940	(21)
Circulatory Systems: Pumps, Vessels, and Blood	941	(1)
Some simple aquatic animals do not have circulatory systems	941	(1)
Open circulatory systems move tissue fluid	941	(1)
Closed circulatory systems circulate blood through tissues	941	(1)
Vertebrate Circulatory Systems	942	(3)
Fish have two-chambered hearts	942	(1)
Amphibians have three-chambered hearts	943	(1)
Reptiles have exquisite control of pulmonary and systemic circulation	944	(1)
Birds and mammals have fully separated pulmonary and systemic circuits	945	(1)
The Human Heart: Two Pumps in One	945	(4)
Blood flows from right heart to lungs to left heart to body	946	(1)
The heartbeat originates in the cardiac muscle	947	(1)
A conduction system coordinates the contraction of heart muscle	948	(1)
Electrical properties of ventricular muscles sustain heart contraction	949	(1)
The EKG records the electrical activity of the heart	949	(1)
The Vascular System: Arteries, Capillaries, and Veins	949	(5)
Arteries and arterioles have abundant elastic and muscle fibers	950	(1)
Blood flows slowly through capillary beds	950	(1)
Materials are exchanged in capillary beds	950	(2)
Blood flows back to the heart through veins	952	(1)
Lymphatic vessels return tissue fluid to the blood	953	(1)
Will you die of cardiovascular disease?	953	(1)
Blood: A Fluid Tissue	954	(2)
Red blood cells transport respiratory gases	954	(1)
Platelets are essential for blood clotting	955	(1)
Plasma is a complex solution	956	(1)
Control and Regulation of Circulation	956	(5)
Autoregulation matches local blood flow to local need	956	(1)
Arterial pressure is controlled and regulated by hormonal and neuronal mechanisms	957	(1)
Cardiovascular control in diving mammals conserves oxygen	958	(3)
Nutrition, Digestion, and Absorption	961	(24)
Nutrient Requirements	962	(6)
Energy can be measured in calories	962	(1)
Energy budgets reveal how animals use their resources	963	(1)
Sources of energy can be stored in the body	963	(1)
Food provides carbon skeletons for biosynthesis	964	(1)
Animals need mineral elements for a variety of functions	965	(1)
Animals must obtain vitamins from food	966	(1)
Nutrient deficiencies result in diseases	967	(1)
Adaptations for Feeding	968	(1)
The food of herbivores is often low in energy and hard to digest	968	(1)
Carnivores must detect, capture, and kill prey	968	(1)
Vertebrate species have distinctive teeth	968	(1)
Digestion	969	(2)
Tubular guts have an opening at each end	969	(1)
Digestive enzymes break down complex food molecules	970	(1)
Structure and Function of the Vertebrate Gut	971	(7)
The vertebrate gut has four tissue layers	972	(1)
Mechanical activity moves food through the gut and aids digestion	972	(1)
Chemical digestion begins in the mouth and the stomach	973	(1)
Most chemical digestion occurs in the small intestine	974	(1)
Nutrients are absorbed in the small intestine	975	(1)
Water and ions are absorbed in the large intestine	976	(1)
Herbivores have special adaptations for digesting cellulose	977	(1)
Control and Regulation of Digestion	978	(1)
Autonomic reflexes coordinate functions in different regions of the gut	978	(1)
Hormones control many digestive functions	978	(1)
Control and Regulation of Fuel Metabolism	978	(2)
The liver directs the traffic of fuel molecules	978	(1)
Lipoproteins: The good, the bad, and the ugly	979	(1)
The hormones insulin and glucagon control fuel metabolism	979	(1)
The Regulation of Food Intake	980	(1)
Toxic Compounds in Food	981	(4)
Some toxins are retained and concentrated in organisms	982	(1)
The body cannot metabolize many synthetic toxins	982	(3)
Salt and Water Balance and Nitrogen Excretion	985	(17)
Tissue Fluid and Water Balance	986	(2)
Excretory organs control the osmolarity of tissue fluid by filtration, secretion, and resorption	986	(1)
Environments and animals can be classified in terms of salts and water	986	(2)
Excreting Nitrogenous Wastes	988	(1)
Aquatic animals excrete ammonia	988	(1)
Many terrestrial animals and some fishes excrete urea	989	(1)
Some terrestrial animals excrete uric acid	989	(1)
Most species produce more than one nitrogenous waste	989	(1)
The Diverse Excretory Systems of Invertebrates	989	(1)
The protonephridia of flatworms excrete water and conserve salts	989	(1)
The metanephridia of annelids process coelomic fluid	990	(1)
The Malpighian tubules of insects depend on active transport	990	(1)
Vertebrate Excretory Systems	990	(3)
Both marine and terrestrial vertebrates must conserve water	990	(2)
The nephron is the functional unit of the kidney	992	(1)
Blood is filtered in the glomerulus	992	(1)
The renal tubules convert glomerular filtrate to urine	993	(1)
The Mammalian Excretory System	993	(5)
Kidneys produce urine, which the bladder stores	993	(1)
Nephrons have a regular arrangement in the kidney	994	(1)
Blood vessels also have a regular arrangement in the kidney	995	(1)
The volume of glomerular filtration is greater than the volume of urine	995	(1)
Most filtrate is resorbed by the proximal convoluted tubule	995	(1)
The loop of Henle creates a concentration gradient in the surrounding tissue	995	(2)
Water resorption begins in the distal convoluted tubule	997	(1)
Urine is concentrated in the collecting duct	997	(1)
The kidneys help regulate acid-base balance	997	(1)
Regulation of Kidney Functions	998	(4)
The kidneys act to maintain the glomerular filtration rate	998	(1)
Blood pressure and osmolarity are regulated by ADH	999	(1)
The heart produces a hormone that influences kidney function	999	(3)
Animal Behavior	1002	(22)
What, How, and Why Questions	1003	(1)
Behavior Shaped by Inheritance	1003	(4)
Experiments can determine whether a behavior is inherited	1004	(1)
Simple stimuli can trigger behavior	1004	(1)
Learning also shapes behavior	1005	(1)
Imprinting is the learning of a complex releaser	1006	(1)
Inheritance and learning interact to produce bird song	1006	(1)
Genetically determined behavior is adaptive under certain conditions	1007	(1)
Hormones and Behavior	1007	(2)
Sex steroids determine the development and expression of sexual behavior in rats	1008	(1)
Testosterone affects the development of the brain regions responsible for song in birds	1009	(1)
The Genetics of Behavior	1009	(3)
Hybridization experiments demonstrate the influence of genes on behavior	1009	(1)
Artificial selection and crossbreeding experiments reveal the genetic complexity of behavior	1010	(1)
Molecular genetic techniques reveal specific genes that influence behavior	1011	(1)
Communication	1012	(2)
Chemical signals are durable but inflexible	1012	(1)
Visual signals are rapid and versatile but are limited by directionality	1012	(1)
Auditory signals communicate well over a distance	1013	(1)
Tactile signals can communicate complex messages	1013	(1)
Electric signals can also communicate messages	1014	(1)
The Timing of Behavior: Biological Rhythms	1014	(3)
Circadian rhythms control the daily cycle of behavior	1014	(2)
Circannual rhythms control seasonal behaviors	1016	(1)
Finding Their Way: Orientation and Navigation	1017	(3)
Piloting animals orient themselves by means of landmarks	1017	(1)