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II •
snl!H' SCJC21nd SUV!10 1CJlldH VC2VPVS •
•
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UOIIIOJ HIH91J
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Cover photograph © Max Billder.
Lecture Notebook to accompany
Life: The Science of Biologtjl Eighth Edition
Copyright © 2008 Sinauer Associates, Inc. All rights reserved.
This book may not be reproduced in whole or in part without permission of the publisher.
Address editorial correspondence to:
Sinauer Associates, Inc.
23 Plumtree Road
Sunderland, MA 01375 US.A. Fax: 413-549-1118 Internet:
www.sinauer.com;
[email protected] Address orders to:
W.H. Freeman and Company
VHPS/W.H. Freeman & Co. Order Department 16365 Janles Madison Highway, US. Route 15 Gordonsville, VA 2 2942 US.A.
ISBN 978-0-7167-78 94-3
Printed in US.A. 43 2
(ontents Part On�
II
Th� Sd�nc� and Building Blocks of Lif�
1 Studying Life 1
2 The Chemistry of Life 7
3 Macromolecules and the Origin of Life 17
Part Two
II
(�lIs and {n�rgy
4 Cells: The Working Units of Life 36 5 The Dynamic Cell Membrane 53
6 Energy, Enzymes, and Metabolism 65
7 Pathways That Harvest Chemical Energy 75 8 Photosynthesis: Energy from Sunlight 90 II
Part Thr��
H�r�dity and th� G�nom�
9 Chromosomes, the Cell Cycle, and Cell Division 101
10 Genetics: Mendel and Beyond 117
11 DNA and Its Role in Heredity 131
12 From DNA to Protein: Genotype to Phenotype 148 13 The Genetics of Viruses and Prokaryotes 163
14 The Eukaryotic Genome and Its Expression 177
Part �our
II
Mol�(Ular Biology: Th� G�nom� in Action
15 Cell Signaling and Communication 191
16 Recombinant DNA and Biotechnology 203
17 Genome Sequencing, Molecular Biology, and Medicine 215
18 Immunology: Gene Expression and Natural Defense Systems 227 19 Differential Gene Expression in Development 243 20 Development and Evolutionary Change 255
Part fiv�
II
Th� Patt�rns and Proc�ss�s of {volution
21 The History of Life on Earth 261
22 The Mechanisms of Evolution 273 23 Species and Their Formation 282
24 The Evolution of Genes and Genomes 287
25 Reconstructing and Using Phylogenies 295
Part Six
•
Th() {volution of Div()rsity
26 Bacteria and Archaea: The Prokaryotic Domains 303 27 The Origin and Diversification of the Eukaryotes 310 28 Plants without Seeds: From Sea to Land 321
29 The Evolution of Seed Plants 330
30 Fungi: Recyclers, Pathogens, Parasites, and Plant Partners 338 31 Animal Origins and the Evolution of Body Plans 346 32 Protostome Animals 354
33 Deuterostome Animals 365
Part Sev()n
•
flowering Plants: form and function
34 The Plant Body 375
35 Transport in Plants 387
36 Plant Nutrition 394
37 Regulation of Plant Growth 399
38 Reproduction in Flowering Plants 409
39 Plant Responses to Environmental Challenges 417
Part {ight
•
Animals: form and function
40 Physiology, Homeostasis, and Temperature Regulation 423 41 Animal Hormones 431
42 Animal Reproduction 445
43 Animal Development: From Genes to Organisms 457
44 Neurons and Nervous Systems 469 45 Sensory Systems 485
46 The Mammalian Nervous System: Structure and Higher Function 499
47 Effectors: How Animals Get Things Done 510
48 Gas Exchange in Animals 523
49 Circulatory Systems 535
50 Nutrition, Digestion, and Absorption 547
51 Salt and Water Balance and Nitrogen Excretion 561
Part Nine
•
{cology
52 Ecology and The Distribution of Life 573 53 Behavior and Behavioral Ecology 591 54 Population Ecology 601
55 Community Ecology 608
56 Ecosystems and Global Ecology 620 57 Conservation Biology 633
(HAPHR
Studying Life
T:::�:Ol�;d'
f O � � : : � : : ::�; 'we "",I.oM"
(C, G,
D
�,
strands of linked sequences of nucleotides.
A gene consists of a specific
sequence of nucleotides.
1��;
; U I� G
i
i
.
/ Gene
DNA �I'--� ----I--"--;�
The nucleotide sequence in a gene contains the information to build a specific protein.
protein
�
1.4 The Genetic Code Is Life's Blueprint (Page 7)
1
2
CHAPHR I
Molecules are made up of atoms. Cells are built of
molecules. Molecule Celis of many types are the working components of living organisms.
, I
!'t.
,
"
A tissue is a group of many cells
with similar and coordinated functions (such as sensing odors).
Tissue (olfactory bulb)
Organ (brain)
--�=I
Organs combine several tissues that
function together. Organs form systems, such as the nervous system.
An organism is a recognizable, self-contained individual. A multicellular organism is made up of organs and organ systems. A population is a group of many
organisms of the same species.
Biological communities in the same geographical location form ecosystems. Ecosystems exchange energy and create Earth's biosphere.
Biosphere
1.6 Biology Is Studied at Many Levels of Organization (Page 8)
STUDYING LIFE
13 20
14
Photosynthesis evolves
21
Eukaryotic cells evolve
27
22
28
23
29
30
24
25
Multicellular organisms
26
� --
Aquatic life Abundant fossils
27
First land plants
28
Coal-forming forests
29
Insects First land animals
First mammals Dinosaurs dominant
Homo sapiens (modern
humans) appeared in the last 10 minutes of day 30.
1 .9 Life's Calendar (Page 1 0)
First birds
30
First flowering plants Rise of mammals
�-------l (- Fir5t hominid5
Homo %lficns
3
4
(HAPHR I
Archaea and Eukarya share a common ancestor not shared by the bacteria.
The eukaryotic cell probably evolved only once. Many different microbial eukaryote (protist) groups arose from this common ancestor.
Three major groups of multicellular eukaryotes evolved from different groups of microbial eukaryotes.
Animals Ancient --------+. Present Time 1.11
The Tree of Life (Page 12)
(XP(RIM(NT
HYPOTHESIS: Something in the environment is causing developmental limb abnormalities in Pacific tree frogs (Hyla regi/la). METHOD
1 . Identify a test area of small ponds in an area where abnormal tree frogs have been found (agricultural land in Santa Clara County, California). 2. Collect and analyze water samples from the ponds. 3. Census the organisms in the ponds. 4. Look for correlations between the presence of frog abnormalities and the characteristics of the ponds. RESULTS
Pacific tree frogs were found in 13 of 35 ponds. Frogs with limb abnormalities were found in 4 of these 13 ponds. Water and census analyses of the 13 ponds containing frogs revealed no difference in water pollution, but did reveal the presence of snails infested with parasitic flatworms of the genus Ribeiroia in the 4 ponds with abnormal frogs.
Ribeiroia
Pesticide residues in water?
Heavy metals in water?
Industrial chemicals in water?
Snails in water?
in water?
larvae in frogs?
Ponds with normal frogs
No
No
No
No
No
No
Ponds with abnormal frogs
No
No
No
Yes
Yes
Yes
Ribeiroia
CONCLUSION: Infection by parasitic Ribeiroia may cause abnormalities in the limb development of Pacific tree frogs.
1.13
Comparative Experiments Look for Differences between Groups (Page 14)
STUDYING LIFE
{XP{RIM{NT HYPOTHESIS: Infection of Pacific tree frog tadpoles by the parasite Ribeiroia causes developmental limb abnormalities. METHOD
1 Collect Hy/a regilla eggs from a site with no record of abnormal frogs. 2. Allow eggs to hatch in laboratory aquaria. Randomly divide equal numbers of the resulting tadpoles into control and experimental groups. 3. Allow the control group to develop normally. Subject the experimental groups to infection with Ribeiroia, a different parasite (A/aria), and a combination of both parasites. 4. Follow tadpole development. Count and assess the resulting adult frogs. .
�«>W� >
� � �!;.�Y
�-Carotene
/ � CH3
CH3
CH3
�OH
H3C
HO
�� H3C
Vitamin A 3.21 p-Carotene is the Source of Vitamin A (Page 56)
CH3
CH3
Vitamin A
MACROMOLECULES AND THE ORIGIN OF LIFE
HO
Cholesterol is a constituent of membranes and is the source of steroid hormones.
,
o
HO
31
Vitamin D2 can be produced in the skin by the action of light on a cholesterol derivative.
o
Cortisol is a hormone secreted
Testosterone is a male sex
by the adrenal glands.
hormone.
3.22 All Steroids Have the Same Ring Structure (Page 57)
Fatty acid
10-CH2 Ester linkage
Alcohol
Page 57 In-Text Art The base may be either a pyrimidine or a purine.
� (p}, � • � 0 � �'- deoxyribose Ribose or Nucleoside Phosphate Nucleotide
IBasel
+
=
+
=
�
o II
H Uracil (U)
Adenine (A) 3.23 Nucleotides Have Three Components (Page 58)
CHAPTn 3
32
The numbering of ribose carbons is the basis for identification of 5' and 3' ends of DNA and RN A strands.
Deoxyribose o
3' end
3' end
Pyrimidine base
5' end
� OH �'
Phosphate ----
N
Phosphodiester linkage 3'end 5' end
In RNA, the bases are attached to ribose. The bases in RNA are the purines adenine (A) and guanine (G) and the pyrimidines cytosine (C) and uracil (U). 3.24 Distinguishing Characteristics of DNA and R NA (Page 58)
" �'.J'••I
Distinguishing RNA from DNA NUCLEIC ACID
SUGAR
BASES
RNA
Ribose
Adenine Cytosine Guanine Uracil
DNA
Deoxyribose
Adenine Cytosine Guanine Thymine
(Page 59)
5' end
In DNA, the bases are attached to deoxyribose, and the base thymine (T) is found instead of uracil. Hydrogen bonds between purines and pyrimidines hold the two strands of DNA together.
MACROMOLECULES AND THE ORIGIN OF LIFE
Double-stranded segments form when sequences of RNA nucleotides pair with one another. Folding brings together complementary but distant base sequences.
3.25 Hydrogen Bonding in RNA (Page 59)
The yellow phosphorus atoms and their attached red oxygen atoms, along with deoxyribose sugars, form the two helical backbones.
3.26 The Double Helix of DNA (Page 60)
The paired bases are stacked in the center of the coil (blue nitrogen atoms and gray carbon atoms).
33
34
CHAPTfR 3
HYPOTHESIS: Organic chemical compounds can be generated under conditions similar to those that existed on primitive Earth. METHOD
A solution of simple chemicals is heated, producing an "atmosphere" of methane, am monia, hydrogen, and water vapor.
A condenser cools the "atmospheric" gases in a "rain" containing new compounds. The compounds collect in an "ocean."
analyzed.
RESULTS
The compounds react in water, eventually forming purines, pyrimidines, and amino acids.
This folded RNA is a ribozyme and can speed ,---==-1' up a reaction.
The short sequences base-pair with the ribozyme.
CONCLUSION: The chemical building blocks of life could have been generated in the probable atmosphere of early Earth.
3.28 Synthesis of Prebiotic Molecules in an Experimental
Atmosphere (Page 62)
These short sequences of RNA are complementary to the ribozyme.
3'
The ribozyme catalyzes the polymerization of the short sequences.
3'
, The short sequences are now one longer sequence of RNA.
5'
3'
-' 5' ...--------3'-3.29 An Early Catalyst for Life? (Page 63)
MACROMOLECULES AND THE O R I G I N OF LIFE
HYPOTHESI S: Life must come from preexisitng life, and is not generated spontaneously. Experiment 1
METHOD
Experiment 2
Boiling kills all micro organisms growing in the nutrient medium.
A long "swan" neck is open to air, but traps dust particles bearing live microorganisms.
broken off, dust particles and live microorganisms enter the flask. Microorganisms grow rapidly in the rich nutrient medium.
Microbial growth
No microbial growth (no spontaneous generation)
CONCLUSION: All life comes from existing life.
3.30 Disproving the Spontaneous Generation of Life (Page 64)
35
(HAPHR
5
"
(�lIs: Th� Working Units of Lif�
This scale is logarithmic. Each unit is 1 0 times bigger than the previous unit.
Atoms
®
UPO'��
T2 phage (virus)
Protein
..,.... .
""" "" '" .,;;;.. ... .
4.1 The Scale of Life (Page 70)
36
,=-
Chloroplast (organelle) rfIIJ& (;)
"�
Most bacteria
Most cell diameters are in
I the range of 1 -1 00 Ilm.
Most plant and animal cells
o Fish egg
Hummingbird
CELLS : T H E WORKING UN ITS OF LIFE
(A) Cubes
Smaller surface area compared to volume.
Larger surface area compared to volume.
..,
Surface area Volume Surface areato-volume ratio
(8) Spheres
�
1 -mm cube 6 sides x 1 2 = 6 mm2 1 3 1 mm3
2-mm cube 6 sides x 2 2 24 mm2 23 = 8 mm3
43 = 64 mm3
6:1
3:1
1 .5:1
=
=
4-mm cube 6 sides x 42 = 96 mm2
Q
Diameter
1 �m
Surface area
4 1t r2
3 . 1 4 �m2
Volume 413 1t r3
0.52 �m3
Surface areato-volume ratio
6:1
3:1
2:1
4.2 Why Cells Are Small (Page 70)
Capsule -
� ,zg
_ _ _ _ _ _ _ _
Nucleoid Plasma membrane Flagellum
200 nm
4.4 A Prokaryotic Cell (Page 73)
Cell wall
t
Peptidoglycan Outer membrane (absent in some bacteria)
37
38
(HAPUR 4
Outside of cell
of flagellum
� �';:=:=:§
Outer ___ membrane
_ _ _ _
Peptidoglycan .-Plasma membrane
Rotor
Transport apparatus
The flagellum is rotated by a complex motor protein secured in the plasma membrane,
4.5 Prokaryotic Flagella (Page 74)
CELLS: THE WORKI NG U NITS OF LIFE
R{S{ARCH M{TH O D A piece of tissue is homogenized by physically grinding it.
The cell homogenate contains large and small organelles.
t
. . q.� �� '�0't, ... ,... , ...;,() ��If� �.C � ...
A centrifuge is used to separate the organelles based on size and density.
Goigi
t
•• The heaviest organelles can be
removed and the remaining suspension re-centrifuged until the next heaviest organelles reach the bottom of the tube.
4.6 Cell Fractionation (Page 75)
39
40
(HAPUR 4
AN ANIMAL CELL
(
Mitochondria are the cell's power plants.
M itocho ndrion
A cytoskeleton composed of
Cy osk eton t
microtubules, intermediate filaments, and microfilaments supports the cell and is involved in cell and organelle movement.
el
The nucleus is the site of most cellular DNA which, with associated proteins, comprises chromatin.
�;2-��--- Rough
endoplasmic reticulum
Ribosomes
Goigi Plasma apparatus membrane
Smooth endoplasmic reticulum
Outside of cell The rough endoplasmic reticulum is the site of much protein synthesis.
with nuclear division. The plasma membrane separates the cell from its environment and regulates traffic of materials into and out of the cell.
4.7 Eukaryotic Cells (Page 76)
1 .5 11m
CELLS: THE WORKING UNITS OF LIFE
A PLANT CELL
t
Free ribosomes
Peroxisome
Smooth endoplasmic reticulum
+ �i$��
-
�
0.5 11m Proteins and other molecules are chemically modified in the smooth endoplasmic reticulum .
Goigi apparatus
!
Nucleolus
41
42
CHAPHR 4
Outer membrane Inner membrane The nuclear envelope is continuous with the endoplasmic reticulum. ��----- Nucleolus ��----- Chromatin Nuclear lamina Nuclear ---- envelope Nuclear pore
_ _ _ �
Inside nucleus Nuclear _ basket
The nuclear lamina is a network of filaments just inside the nuclear envelope. It interacts with chromatin and helps support the envelope to which it is attached.
f
1
Cytoplasmic filament
Inside cell
4.8 The Nucleus Is Enclosed by a Double Membrane (Page 78)
An octagon of protein complexes surrounds each nuclear pore. Protein fibrils on the nuclear side form a basketlike structure.
CELLS: THE WORKING UNITS OF LIFE
Rough endoplasmic reticulum is studded with ribosomes that are sites for protein synthesis. They produce its rough appearance.
Smooth endoplasmic reticulum is a site for lipid synthesis and chemical modification of proteins.
Inside of cell
4.10 Endoplasmic Reticulum (Page 80)
43
44
(HAPHR 4
The Goigi apparatus processes and packages proteins.
Protein-containing vesicles from the endoplasmic reticulum transfer substances to the cis region of the Golgi apparatus.
Nucleus
Inside of cell
The Golgi apparatus chemically modifies proteins in its lumen . . .
. . . and "targets" them to the correct addresses.
Smooth endoplasmic reticulum
Proteins for use within the cell
�
. :r,.•, . , .' .' • -.. . . . , ,:-': ;i�': . Proteins for use , " : .'. ! .. : outside the cell
. .. ::: =======!:!;>'" .:::=
Plasma membrane �
Outside of cell
4.1 1 The Goigi Apparatus (Page 81)
CELLS: THE WORKING UNITS OF LIFE
Inside of cell
')
The lysosome fuses with a phagosome. Small molecules generated by digestion diffuse into the cytoplasm.
e / Phagosome � � Secondary I. lysosome Primary lysosome
Plasma Outside of cell
Undigested materials are released.
1
flm
4.12 Lysosomes Isolate Digestive Enzymes from the Cytoplasm (Page 82)
45
46
CHAPHR 4
Intermembrane space
The cristae contain key molecules for the generation of ATP from fuel molecules.
The inner membrane is the primary barrier between the cytosol and mitochondrial enzymes.
The matrix contains ribosomes, DNA, and several of the enzymes used for cellular respiration.
4.1 3 A Mitochondrion Converts Energy from Fuel Molecules into ATP (Page 83)
CELLS: THE WORKING UNITS OF LIFE
47
ATP is used in converting CO2 to glucose in the stroma, the area outside the thylakoid membranes.
4.14 Chloroplasts Feed the World (Page 84)
Thylakoid membranes are sites where light energy is harvested by the green pigment chlorophyll and converted into ATP.
Peroxisome
4.17 A Peroxisome (Page 85)
4.1 8 Vacuoles in Plant Cells Are Usually Large (Page 85)
48
CHAPH R 4
(XP(R IM(NT HYPOTHESIS: Amoeboid cell movements are caused by the cytoskeleton. METHOD
Amoeba proteus is a single-celled eukaryote that moves by extending its membrane.
Amoeba treated with
The drug cytochalasin B is a drug that breaks apart microfilaments, part of the cytoskeleton
Control: Untreated Amoeba
RESULTS
Treated Amoeba rounds up and does not move
Untreated Amoeba continues to move
CONCLUSION: Microfilaments of the cytoskeleton are essential for amoeboid cell movement.
4.1 9 Showing Cause and Effect in Biology (Page 86)
49
CELLS: THE WOR KING UNITS OF LIFE
Rough endoplasmic reticulum Mitochondrion
Plasma membrane
f
O End
Microfilaments
O E"d
Actin monomer
Intermediate filament
1
Microtubule
O End
7 nm
T
Fibrous subunit
CD§)
'-y-----'
Tubulin dimer
1
monomer
O End
T 1
25 nm
monomer
'------'
20 11m (A) Microfilaments
Made up of strands of the protein actin and often interact with strands of other proteins. They change cell shape and drive cellular motion, including contraction, cytoplasmic streaming, and the "pinched" shape changes that occur during cell division. Microfilaments and myosin strands together drive muscle action. •
•
•
1 0 11m (8) Intermediate filaments
Made up of fibrous proteins organized into tough, ropelike assemblages that stabilize a cell's structure and help maintain its shape. Some intermediate filaments help to hold neighboring cells together. Others make up the nuclear lamina. •
•
(C)
Microtubules
Long, hollow cylinders made up of many molecules of the protein tubulin. Tubulin consists of two subunits, a-tubulin and �-tubulin. Microtubules lengthen or shorten by adding or subtracting tubulin dimers. Microtubule shortening moves chromosomes. Interactions between microtubules drive the movement of cells. Microtubules serve as "tracks" for the movement of vesicles. •
•
•
•
•
4.20 The Cytoskeleton (Page 87)
50
CHAPTfR 4
A cap of proteins is attached to the end of microfilaments.
Actin microfilaments run the entire length and support each microvillus.
Cross-linking actin-binding proteins link microfilaments to each other and to the plasma membrane.
Intermediate filaments
4.21 Microfilaments for Support (Page 88) (A)
The beating of the cilia covering the surface of this unicellular protist propels it through the water of its environment.
(8)
Cross-section reveals the "9+2" pattern of microtubles, including nine pairs of fused microtubles . . .
. . . and two unfused inner microtubules.
Radial "spokes" Motor protein (dynein; see Figure 4.23)
Three cilia
�
Linker protein (nexin)
-50 nm
Microtubule triplet
4.22 Sliding Microtubules Cause Cilia to Bend (Page 89)
"------' -25 nm
CELLS: THE WORKING UNITS OF LIFE
(A)
51
Microtubule doublets (see Figure 4 . 22) ,.-A-..
Dynein reattaches, causing sliding.
(C)
(8)
+
+
Kinesin cross links the vesicle to the microtubule.
Detachment and reattachment of kinesin causes it to "walk" along microtubule.
Cell wall of cell 1
,-------A--.
4.23 Motor Proteins Drive Vesicles along Microtubules (Page 90)
Interior of cell 2 '----y--J
Cell wall of cell 2
4.24 The Plant Cell Wall (Page 91)
'------'
1 .5 11m
52
CHAPTIR 4
Proteoglycans have long polysaccharide chains that provide a viscous medium for filtering. The basal lamina is an extracellular matrix (ECM). Here it separates kidney cells from the blood vessel.
The ECM is composed of a tangled complex of enormous molecules made of proteins and long polysaccharide chains.
'-------'
1 00 nm 4.25 An Extracellular Matrix (Page 91)
/ Plasma membrane of larger cell
Double membranes may have originated when one cell engulfed another.
Plasma membrane of smaller cell 4.26 The Endosymbiosis Theory (Page 92)
Chloroplast
Th� Dynamic (�II M�mbran�
Carbohydrates are attached
Outside of cell
to the outer surface of proteins (forming glycoproteins) or lipids (forming glycolipids).
In animal cells, some membrane proteins associate with filaments in the extracellular matrix.
Some integral proteins cross the entire phospholipid bilayer; others penetrate only partially into the bilayer. Inside of cell
Peripheral proteins
do not penetrate the bilayer at all.
Cholesterol molecules interspersed
proteins interact with the interior cytoskeleton.
among phospholipid tails in the bilayer influence the fluidity of fatty acids in the membrane.
5.1 The Fluid Mosaic Model (Page 98)
53
(HAPHR 5
54
Aqueous environment
CO
The nonpolar, hydrophobic fatty acid
-J "tails" interact with one another in the interior of the bilayer.
The charged, or polar, hydrophilic "head" portions interact with polar water.
Aqueous environment 5.2 A Phospholipid Bilayer Separates Two Aqueous Regions (Page 99)
THE DYNAMIC CELL MEMBRANE
55
R{S{ARCH M{TH O D
Fracturing causes one half of the membrane to separate from the other along the weak hydrophobic interfaces.
5.3 Membrane Proteins Revealed by the Freeze-Fracture Technique (Page 100)
Hydrophilic R groups in exposed parts of the protein interact with aqueous environments.
}
Hydrophobic interior of bilayer
Hydrophobic R groups interact with the hydrophobic core of the membrane, away from water.
5.4 Interactions of Integral Membrane Proteins (Page 100)
56
(HAPUR 5
New stretches of membrane may be generated at certain locations, such as the endoplasmic reticulum. Membrane proteins are inserted at the rough ER.
Nucleus
Inside of cell
Vesicles budding from the trans region of the Golgi apparatus are also membrane-enclosed.
Lysosome
Go i gi
apparatus
Smooth endoplasmic reticulum
�g
./'
.' ':!"'"
,,: . . .• ;
.... � . . �===�r ),::'1 ':'" . ,� '''.. :
a�
Exocytosis
.
'
Pl membrane
Outside of cell •
5.5 Dynamic Continuity of Membranes (Page 1 0 1)
Membrane is extracted from the plasma membrane by endocytosis.
, The vesicles may remain inside the cell as organelles, such as Iysosomes. . .
. . . or they may fuse with the plasma membrane, delivering their contents to the exterior of the cell (exocytosis). Their membranes are then added to the plasma membrane.
THE DYNAMIC CELL MEMBRANE
(A) Homotypic binding
57
(8) Heterotypic binding
Tissue from a red sponge contains similar cells bound to each other. The sponge tissue can be separated into single cells by passing it through a fine mesh screen.
(9 @
0
G
+ 0 0 i®-
0 0 1i>
0,�,� G 0 �,
� �
1i>
Mating type
5.6 Cell Recognition and Adhesion (Page 103)
,/ "
J
(�\ � '- "
,
1;1
Mating type
�1'� � l r�
m Exposed regions of membrane glycoproteins bind to each other causing cells to adhere.
� � �
These gametes from a marine alga look identical but have different cell surface proteins.
@> @> @>
'
The gametes adhere to each other by complementary protein binding.
58
(HAPUR 5
(A) Plasma membranes Intercellular space
�,�',�,��-COOOOo��OOllIOl)
Junctional proteins (interlocking) The proteins of tight junctions form a "quilted" seal, barring the movement of dissolved materials through the space between epithelial cells, ( 8)
Plasma membranes """"'==Intercellular space
_ _
Desmosomes
Desmosomes link adjacent cells tightly but permit proteins materials to move around them in the intercellular space.
(e)
Gap junctions let adjacent
cells communicate.
5.7 Junctions Link Animal Cells Together (Page 104)
THE DYNAMIC CELL MEMBRANE
(XP(RIM(NT HYPOTHESIS: Diffusion leads to a uniform distribution of solutes. METHOD
RESULTS
Add equal amounts of three dyes to still water in a shallow container. -
Sample different regions of the solution and measure the amount of each colored dye.
Time
c o
=
-
0
5 minutes later
1 0 minutes later
� C Ql o C o
o
The number and position of molecules of each dye can be rendered visually.
.. . .. . ........ . . . .. . . ... .. ....,..... . . . . .. . . .. ... .
.. . ..
... . .. . . . ...
.. . . ...... ..t.� .. .-.·. e* . : :.. ... •., .•. ,: ::........:.. .
•
•
•
• ••• • • a
••
CONCLUSION: Solutes distribute themselves by diffusion, uniformly and independently of each other.
5.8 Diffusion Leads to Uniform Distribution of Solutes (Page 106)
59
60
(HAPHR 5
Hypotonic (dilute solutes outside)
Isotonic (equivalent solute concentration)
Hypertonic (concentrated solutes outside)
Animal cell (red blood cells)
Cells lose water and shrivel. Cells take up water, swell, and burst.
Plant cell (leaf epithelial cells)
Cell stiffens but generally retains its shape because cell wall is present.
Cell body shrinks and pulls away from the cell wall (wilting),
Vacuole
5.9 Osmosis Can Modify the Shapes of Cells (Page 107)
A polar substance is more concentrated on the outside than the inside of the cell. Outside of cell
Stimulus molecule
Channel protein
Binding of a stimulus molecule causes the pore to open" ,
Pore
Inside of cell
5.10 A Gated Channel Protein Opens in Response to a Stimulus (Page 108)
THE DYNAMIC CELL MEMBRANE
(A) Side view
Potassium ions fit uniquely inside the funnel.
(8)
"Top down" view
Outside of cell
a-Helix of the channel protein
Inside of cell
5.1 1 The Potassium Channel (Page 1 09)
(A)
(8)
Outside of cell
Glucose concentration The carrier protein returns to its original shape, ready to bind another glucose.
Inside of cell
5.1 2 A Carrier Protein Facilitates Diffusion (Page 1 1 0)
Membrane Transport Mechanisms TRANSPORT MECHANISM
EXTERNAL ENERGY REQUIRED?
DRIV ING FORCE
MEMBRANE PROTEIN REQUIRED?
SPECIFICITY
Simple diffusion
No
With concentration gradient
No
Not specific
Facilitated diffusion
No
With concentration gradient
Yes
Specific
Active transport
Yes
ATP hydrolysis (against concentration gradient)
Yes
Specific
(Page 1 1 1)
61
CHAPUR 5
62
Uniport transports one substance in one direction. Outside
Symport transports two different substances in the same direction.
Antiport transports two different substances in opposite directions.
of cell
Inside of cell
5.1 3 Three Types of Proteins for Active Transport (Page 111)
Outside of cell
•
bind to the protein "pump."
o
•
The shape change releases Na+ outside the cell and enables K+ to bind to the pump.
o
Hydrolysis of ATP phosphorylates the pump protein and changes its shape.
Release of Pi retums the pump to its original shape, releasing K+ to the cell's interior and once again exposing Na+ binding sites. The cycle repeats .
o
o G O
Inside of cell
5.14 Primary Active Transport: The Sodium-Potassium Pump (Page 112)
THE DYNAMIC CELL MEMBRANE
Secondary active transport
Na+, moving with the concentration gradient established by the sodium potassium pump, drives the transport of glucose against its concentration gradient.
Primary active transport
The sodium-potassium pump moves Na+ , using the energy of ATP hydrolysis to establish a concentration gradient of Na+ .
o
ADP
+ .
Outside
Pi
t''-- QO �O�
o
K+
Na+
0
()
()
5.1 5 Secondary Active Transport (Page 1 12)
(A) Endocytosis Outside of cell
The plasma membrane surrounds a part of the exterior environment and buds off as a vesicle.
A vesicle fuses with the plasma membrane. The contents of the vesicle are released, and its membrane becomes part of the plasma membrane.
(8) Exocytosis
5.16 Endocytosis and Exocytosis (Page 1 13)
of cell
63
64
(HAPHR S
(A) Energy transformation Outside of cell Outside
A membrane pigment absorbs energy.
Inside of cell
The membrane pigment transfers the energy to ADP to form ATP. which the cell can use as an energy source.
(8) Organizing chemical reactions
The product of the first reaction must diffuse to reach the site of the second reaction.
they occur at the same time and place.
(e) Information processing
5.1 8 More Membrane Functions (Page 115)
(HAPHR
{nergy, {nzymes, and Metabolism
Energy transformation
(A) The First Law of Thermodynamics.
The total amount of energy before a transformation equals the total amount after a transformation. No new energy is created, and no energy is lost.
Energy before
_==::::; A measuring device
indicates that the total energy does not change.
( 8)
Energy transformation
The Second Law of Thermodynamics.
Although a transformation does not change the total amount of energy within a closed system, after any transformation the amount of energy available to do work is always less than the original amount of energy.
\
Usable energy after (free energy) Urnwsable 8/iler§Y after
Energy before
Energy transformations Free energy
..
Another statement of the second law is that in a closed system, with repeated energy transformations free energy decreases and unusable energy increases-a phenomenon known as the creation of entropy.
..
..
�
r-----
..
Unusable energy after
6.2 The Laws of Thermodynamics (Page 121)
65
66
(HAPHR 6
(A) Exergonic reaction
Reactants
- - - - - - - - - - - - - -
>-
2'
f
- - - -
Amount of energy released
OJ c OJ OJ
e:
u..
In an exergonic reaction, energy is reactants form lower energy products. �G is negative.
released as the
Course of reaction (8) Endergonic reaction
Products
----r= Amount of
>-
2' OJ c OJ OJ
Energy must be added for an endergonic
reaction, in which reactants are converted to products with a higher energy level. �G is positive.
energy required
e:
�
u..
�- - - - - - - - - - - - - - - - - . �
Reactants
Course of reaction 6.3 Exergonic and Endergonic Reactions (Page 122)
4
r==�
Reaction to equilibrium
•
'l� ' -\-----cJ:-=-- - " d-r(-3
1 00% Glucose 1 -phosphate (0.02 M concentration) 6.4 Chemical Reactions Run to Equilibrium (Page 123)
-2
95% Glucose 6-phosphate (0.01 9 M concentration) 5% Glucose 1 -phosphate (0.001 M concentration)
ENERGY, ENZYMES, AND METABOLISM
67
(A) ATP
(space-filling model)
ATP
(structural formula)
Adenine
Phosphate groups
Ribose Adenosine AMP ADP
@
(Adenosine monophosphate)
(Adenosine diphosphate)
(Adenosine triphosphate)
(8)
6.5 ATP (Page 124)
Exergonic reaction:
Endergonic reaction:
(releases energy) Cell respiration Catabolism
(requires energy) Active transport Cell movements Anabolism
• •
•
• •
requires energy. 6.6 Coupling of Reactions (Page 125)
(HAPUR 6
68
Exergonic reaction (releases energy) fiG
=
-7.3 kcal/mol
Endergonic reaction (requires energy) o
8-< + 0-
Glutamate
o
8-
,
e> Q) c Q) Q)
�
LL
- - - - - - - -
r
- - - - -
L'lG -.===::::;;:::'
!
6.G for the
reaction is not affected by Ea'
Products Ea is the activation energy required for a reaction to begin.
Course of reaction
(6) >,
The ball needs a push (Ea) to get it out of the depression.
e> Q) c Q) Q)
�
LL
>,
e> Q) c Q) Q)
�
LL
Less stable state (transition state)
A ball that has received an
�=::-.....J input of activation energy can roll downhill spontaneously, releasing free energy.
6.8 Activation Energy Initiates Reactions (Page 126)
ENERGY, ENZYMES, AND METABOLISM
Product
'8
Substrates fit precisely into the active site . . .
----1.�
. . . but non substrate does not.
Enzyme-substrate complex 6.9 Enzyme and Substrate (Page 127)
>-
2l
/ Uncatalyzed reaction
An uncatalyzed reaction has greater activation energy than does a catalyzed reaction.
Q) c Q) Q)
e?
LL
There is no difference in free energy between catalyzed and uncatalyzed reactions.
Catalyzed reaction Products Course of reaction
6.10 Enzymes Lower the Energy Barrier (Page 127)
� Enzyme
The breakdown of the enzyme substrate complex yields the product. The enzyme is now available to catalyze another reaction.
69
70
(HAPTfR 6
(A) Two substrates are bound at the active site of the enzyme citrate synthase.
4P' z....
The active site of lysozyme strains and flattens its polysaccharide substrate.
(8)
"
The enzyme strains the substrate.
,
,
,
,
,
,
,
,
,
,
���----�
Two amino acids at the active site of chymotrypsin become charged when in contact with the substrate.
6.1 1 Life at the Active Site (Page 128)
Empty active site
When the substrate binds to the active site, the two side chains move together, changing the shape of the enzyme so that catalysis can take place.
6.12 Some Enzymes Change Shape When Substrate Binds to Them (Page 129)
ENERGY, ENZYMES, AND M ETABOLISM
" :I;U«1I1
An enzyme speeds up the reaction. At the maximum reaction rate, however, all enzyme molecules are occupied with substrate molecules.
Some Examples of Nonprotein "Partners" of Enzymes TYPE OF MOLECULE
Iron (Fe2+ or Fe3+) Copper (Cu+ or Cu2+) Zinc (Zn2+) COENZYMES Biotin Coenzyme A NAD FAD
ATP PROSTHETIC GROUPS Heme Flavin Retinal
Maximum rate
ROLE IN CATALYZED REACTIONS
COFACTORS
Oxidation/reduction Oxidation/reduction Helps bind NAD Carries - COOCarries - C H - C H3 2 Carries electrons Carries electrons Provides/extracts energy
Q)
1§ c a
�
Q) ((
-- -- - - - - - - - - --� - -:.; - -.;;.:;. - --..--.-. -
" Reaction with enzyme
--.;.-
-
With no enzyme present, the reaction rate increases steadily as substrate concentration increases.
Reaction without enzyme '--.. Concentration of substrate
6.1 4 Catalyzed Reactions Reach a Maximum Rate (Page 130)
Binds ions, O2, and electrons; contains iron cofactor Binds electrons Converts light energy
(Page 129)
6.1 3 An Enzyme with a Coenzyme (Page 130)
71
6.1 5 Metabolic Pathways (Page 131)
72
(HAPUR 6
Hydrogen fluoride
The hydroxyl group is on the side chain of serine in the active site.
DIPF, an irreversible inhibitor, reacts with the hydroxyl group of serine.
Covalent attachment of DIPF to the active site prevents substrate from entering.
6.1 6 Irreversible Inhibition (Page 132)
(A)
Competitive inhibition
/ Competitive
/' Substrate
inhibitor
substrate "compete;" only one can bind to the active site.
(8) Noncompetitive inhibition
SUbstrate �
Noncompetitive inhibitor
An inhibitor may bind to a site away from the active site, changing the enzyme's shape so that the substrate no longer fits.
6.1 7 Reversible Inhibition (Page 132)
ENERGY, ENZYMES, AND METABOLISM
I nactive form
Active form
Catalytic subunit \
When the enzyme is in the inactive form, it cannot accept substrate.
When the enzyme is in the active form, it can accept substrate.
� ...".---
site
Activator site
Regulatory subunits
II
Binding of an inhibitor makes it less likely that the active form will occur.
II
Allosteric inhibitor
activator
�
�
No product formation
Product formation
6,18 Allosteric Regulation of Enzymes (Page 133)
(A) Nonallosteric enzyme
(8) Allosteric enzyme
OJ
�
c o
TI m
a:
Concentration of substrate 6.19 AIIostery and Reaction Rate (Page 133)
Binding of an activator makes it more likely that the active form will occur.
73
OIAPHR 6
74
Each of these reactions is catalyzed by a different enzyme, and each forms a different intermediate product.
The first reaction is the commitment step.
,_ _ _ .J
NH 3+
o
II
I
I
\
NH 3+
I
H - C - COO-
I
H - C - COO
C - COO- ..... ..... ..... .....
H - C - OH
CH2
CH2
CH3
CH3
CH3
I
I
Threonine (starting material)
Isoleucine (end product)
a-Ketobutyrate (intermediate product) Buildup of the end product allosterically inhibits the enzyme catalyzing the commitment step, thus shutting down its own production.
6.20 Feedback Inhibition of Metabolic Pathways (Page 134)
Salivary amYlaSe
�
� c o
�
Q) a:
2
3
4
5
8
7
6
9
10
6.21 pH Affects Enzyme Activity (Page 134)
� c o
� co Q) a:
Optimal temperature
11
12 Basic
pH
Acidic
I
I
I
I
H - C - CH3
I
""' :
Temperature
6.22 Temperature Affects Enzyme Activity (Page 134)
(HAPHR
Pathways That Harvest (hemical {nergy
Sun
(A) Glycolysis and cellular respiration GLYCOLYSIS
(8) Glycolysis and fermentation
GLYCOLYSIS
Anaerobic FERMENTATION
CELLULAR RESPIRATION •
•
•
Complete oxidation Waste products: H 20, CO2 Net energy trapped: 32
®
•
•
•
Incomplete oxidation Waste prodwcts: Organic compound (lactic acid or ethanol) and CO2 Net energy trapped: 2
@-
PYRUVATE OX:IDATION
7.1 Energy for Life (Page 140)
EbECrR.(ii)N TRANSf'0RT QHAIN
7.2 Energy-Producing Metabolic Pathways (Page 141)
75
76
(HAPUR 7
Reduced compound A
B
Oxidized compound B
(reducing agent)
(oxidizing agent)
Oxidized compound A
Reduced compound B
7.3 Oxidation and Reduction Are Coupled (Page 1 4 1)
1"'i,,_,,1
Cellular Locations for Energy Path ways in Eukaryotes and Prokaryotes EUKARYOTES
PROKARYOTES
External to mitochondrion
In cytoplasm
Glycolysis
Glycolysis
Fermentation
Fermentation Citric acid cycle
Inside mitochondrion
Inner membrane Electron transport chain Matrix Citric acid cycle Pyruvate oxidation (Page 141)
On plasma membrane
Pyruvate oxidation Electron transport chain
PATHWAYS THAT HARVEST CHEMICAL ENERGY
(A) NAD+
(NAIJI;1) +
� (8)
Two hydrogen atoms (2 e + 2 H+) are transferred.
, ONH C N 0-"P� 0 -C 2 0 6 o � H HOH HOH H NH2 N> o 6N �0 o _ �� l p / 0- H H H H OH OH
Oxidized form (NAD+)
H
�+
I
�
�
o: :
( (\(\111011)+ (tj )
ed "' d for
I
7.4 NAD Is an Energy Carrier in Redox Reactions (Page 142)
I
I
CONH2
+
77
78
OIAPHR 7
GLYCOLYSIS
� HH CHPH O H
Glyceraldehyde3-phosphate (G3P) (2 molecules)
H
OH
HO
OH
CHP
ENERGY -HARVESTING REACTIONS
ENERGY -INVESTING REACTIONS
OH
I
H- C- OH I C=O I H
JF
Triose phosphate dehydrogenase
Glucose
1 r-� 0'- �
ATP transfers a phosphate to the 6-carbon sugar glucose.
�:,H o 0 OH
OH
1 -I 0
H 0 0H �CH2 H C
2
H
OH
t� A second ATP
transfers a phosphate to create fructose1 ,6-bisphosphate.
HO
Phosphofructokinase
1 r-� 0� �
(2 molecules)
2
@
2@
I. The two molecules of BPG
transfer phosphate groups to AOP, forming two ATPs and two molecules of 3-phosphoglycerate (3PG).
3-Phosphoglycerate (3PG) (2 molecules)
I� I 0
oThe phosphate groups on
the two 3PGs move, forming two 2-phosphoglycerates (2PG).
2-Phosphoglycerate (2PG) (2 molecules)
� 0HO H OH
CHP
H
OH
t) The fructose ring opens, and
the 6-carbon fructose 1 ,6-bisphosphate breaks into the 3-carbon sugar phosphate OAP and its isomer G3P.
is rearranged to form another G3P molecule.
gain phosphate groups and are oxidized, forming two molecules of NADH + H+ and two molecules of 1 ,3bisphosphoglycerate (BPG).
Fructose-6-phosphate (F6P)
CH P
I� The OAP molecule
CH20 0-
" The two molecules of G3P
1 ,3-Bisphosphoglycerate (BPG)
I H- C- OH I C=O I Phosphoglyceromutase
OH
H
I- � 0
Phosphoglycerate kinase
Phospho hexose Isomerase
is rearranged to form its isomer, fructose6-phosphate.
2 NADH +
o
Glucose-6-phosphate (G6P)
II Glucose 6-phosphate
OPi
2 NAD+
CHP I H- C- OH I C=O I
Hexokinase
HO
2
il
CHP I C=O I
CH20H
Isomerase
Dihydroxyacetone phosphate (DAP)
CHP I H- C- OH I C=O I
H
Glyceraldehyde3-phosphate (G3P) (2 molecules)
7.5 Glycolysis Converts Glucose into Pyruvate (Page 143)
lose water, becoming two high-energy phospho enolpyruvates (PEP).
II
H
C-OI C=O I
Fructose-1 ,6-bisphosphate (FBP) Aldol=
CH2 0-I�r---
� The two molecules of 2PG
Pyruvate kinase
0----
Phosphoenolpyruvate (PEP) (2 molecules)
2 2
@
@
� Finally, the two PEPs
transfer their phosphates to ADP, forming two ATPs and two molecules of pyruvate.
CH3
I
c=o
I
c=o
0-I
Pyruvate (2 molecules)
From every glucose molecule, glycolysis nets two molecules of ATP and two molecules of the electron carrier NADH. Two molecules of pyruvate are produced.
79
PATHWAYS THAT HARVEST CHEMICAL ENERGY
ENERGY-INVESTING REACTIOt-;!S (endergonic)
g 0 E
.0;:. c = ;;;:.
e> Ql c Ql Ql
Glyceraldehyde3-phosphate
2 NAD+
� () (9
� �
>-
e' OJ c OJ
30
�,
�_ � 11� .'1
Cytochrome c reductase complex
20 Cytochrome c oxidase complex
OJ
e2
LL
10
o
7 . 1 2 The Complete Electron Transport Chain (Page 150)
.. O2
H0 2
PATHWAYS THAT HARVEST CHEMI CAL ENERGY GLYCOLYSIS (GI SS>
U
Intermembrane space Matrix A highly magnified view of the inner mito chondrial membrane. "Lollipops" project into the mitochondrial matrix; these knobs (ATP synthase) catalyze the synthesis of ATP.
Mitochondrion Cytoplasm Outer mitochondrial membrane
jJ
Intermembrane space (high concentration W of )
�
.J.,J�j�
J
ELECTRON TRANSPORT
ATP SYNTHESIS
( ,.______________ ... ---" A'- ______________�, r,....-----�A'---�,
ATP
+
2
Matrix of mitochondrion W (low concentration of ) Electrons (carried by NADH and FADH 2) from glycolysis and the citric acid cycle "feed" the electron carriers of the inner mitochondrial rnernbrane, which pump protons (W) out of the matrix to the intermembrane space.
Proton pumping creates an imbalance of W -and thus a charge difference-between the intermembrane space and the matrix. This i rnbalance is the proton-motive force.
7 . 1 3 A Chemiosmotic Mechanism Produces ATP (Page 15 1)
@+OP;
-/d
lID
f) Because of the proton-motive force, protons return to � ___
the matrix by passing through the W channel of ATP synthase (the Fa unit). This movement of protons is coupled to the formation of ATP in the F1 unit.
85
86
CHAPTn 7
{XP{RIM{NT Z
{XP{RIM{NT 1 HYPOTHESIS: An H+ gradient can drive ATP synthesis by isolated mitochondria.
HYPOTHESIS: ATP synthase is needed for ATP synthesis.
� METHOD
�
A proton pump extracted from bacteria is added to an artificial lipid vesicle.
Mitochondria are isolated from cells and placed in a medium at pH 8. This results in a low H + concentration both outside and inside the organelles.
H+ is pumped into the vesicle, creating a gradient.
The mitochondria are moved to an acidic medium (pH 4; high W concentration) .
ATP synthase from a mammal is inserted into the vesicle
RESULTS H+ movement into mitochondria drives the synthesis of ATP in the absence of continuous electron transport.
RESULTS
G)
CONCLUSION: In the absence of electron transport, an artificial W gradient is sufficient for ATP synthesis by mitochondria.
G) G) G)
The H + diffuses out of the vesicle, driving the synthesis of ATP by ATP synthase.
CONCLUSION: ATP synthase, acting as an H+ channel, is necessary for ATP syn thesis.
7.1 4 Two Experiments Demonstrate the C hemiosmotic Mechanism (Page 152)
PATHWAYS THAT HARVEST CHEMICAL ENERGY
87
GLYCOLYSIS
I------+-�.
2 (NADfi
2@
FEI!!MENTATION
2 Lactate (3 carbons) or 2 Ethanol (2 carbons) 2 CO2 4-
21c021 2 acetyl groups as acetyl CoA (2 carbons)
'< I II
7.15
+ 6 02
.2@
51H201
Summary of reactants and products: C6 H ,206
41co21
28@
ELECTRON TRANSPORt CHAIN
50
•
-
6 CO2 + 6
H20
+
� 32er-
Cellular Respiration Yields More Energy T han Glycolysis Does (Page 153)
(HAPHR 7
88
Lipids (trigly cerides)
Polysaccharides i�4:===��: (starch) I� Glycerol
Fatty acids
7.16
Relationships among the Major Metabolic Pathways of the Cell (Page 154)
a-Ketoglutarate is an intermediate in the citric ac cycle.
id
coo
I
C=O
I
CH2
I
CH2
I
COO-
7.17
Coupling Metabolic Pathways (Page 155)
PATHWAYS THAT HARVEST CHEMICAL ENERGY
Compound G provides positive feedback to the enzyme catalyzing the step from D to E.
89
Compound G inhibits the enzyme catalyzing the conversion of C to F, blocking that reaction and ultimately its own synthesis.
·�rF I
C
I " Positive feedback ......, t �-E
'"
Negative feedback
----� :� G
GLYCOLYSIS
Glucose
7.1 8 Regulation by Negative and Positive Feedback
(Page 156) ADP or AMP activates phospho fructokinase. ATP inhibits phosphofructo kinase.
@ or -+� AMP
Phosphofructokinase
Citrate inhibits phosphofructo kinase.
ATP or NADH inhibit citrate synthase.
Citrate activates this enzyme.
ADP or NAD+ activate isocitrate dehydrogenase. ATP or NADH inhibit isocitrate dehydrogenase. ELECTRON TRANSPORT CHAIN
7.1 9 Allosteric Regulation of Glycolysis and the Citric Acid Cycle
(Page 156)
(HAPHR
Photosynth�sis: {n�rgy from Sunlight &
H20 Gil
S unlight
Leaf
Sugars, the products of photosynthesis, are transported throughout the plant body. CO2 enters and O2 and water exit the leaves through pores on the leaf s urface called stomata.
(XP(RIM(NT HYPOTHESIS: The oxygen released by photo synthesis comes from water rather than from CO2, Experiment 2
Experiment 1
H2O,cB
H2i1!], CO2
METHOD Give plants isotope- labeled water, and unlabeled CO2,
t
• '"
Give plants isotope-labeled carbon dioxide, and unlabeled water.
t
8.1 The Ingredients for Photosynthesis (Page 162)
II+!
RESULTS
I
The oxygen released is labeled.
t
�
� t
O2
e oxygen released is unlabeled.
CONCLUSION: Water is the source of the O2 produced by photosynthesis.
8.2 Water Is the Source of the Oxygen Produced by Photosynthesis (Page 162)
90
PHOTOSYNTHESIS: ENERGY FROM SUNLIGHT
91
Chloroplast
8.3 An Overview of Photosynthesis (Page 163) ( ) A
o�
Photon
Excited state
Absorption of photon by molecule Ground
--------4lI0>-- state
When a molecule in the ground state absorbs a photon, it is raised to an e xcited state and possesses more energy. 8 ( )
Photon o
Ground state
Excited state
The absorption of the photon boosts an electron to a shell farther from its atomic nucleus.
8.4 Exciting a Molecule (Page 164)
92
CHAPUR 8
Cosmic rays Gamma rays
Wavelength (nm)
MJVWWV\MI\NVVVV
Infrared (IR)
) (A
Blue and red wavelengths are absorbed by chlorophyll a" ,
1
b bt
C
OJ
'is. >.D C 0 E. 0 (/)
Microwaves Radio waves
8.5
The Electromagnetic Spectrum (Page 164)
p t
A sor io n s ec ru m of chlorophyll a
Q) E
.D .D (/) 'w Q) ..c
C >(/) 0 '0
..c 0...
400 450 500 550 600 650 700 750 Wavelength (nm) Vi s i ble spectrum : , , ,
8.6
.
, , �, , ,
Absorption and Action Spectra (Page 165)
PHOTOSYNTHESIS: ENERGY FROM SUNLIGHT Chloroplast
Light is absorbed by the complex ring structure of a chlorophyll molecule. S troma
H-C--C
I I I CH
C=O
�
0
o
3
Hydrocarbon tails secure chlorophyll molecules to hydrophobic proteins inside the thylakoid membrane.
8.7
Thylakoid interior The energized electron from the chlorophyll molecules can be passed on to an electron acceptor to reduce it.
The Molecular Structure of Chlorophyll (Page 165) Photon
Excited s tate-
@� �� 7 Electron acceptor
��-----�y�----�) 8.8
Antenna system embedded in thylakoid membrane
Proteins
Energy Trans fer and Electron Transport (Page 166)
93
CHAPUR 8
94
Photosystem I
2i)
Photosystem II
2(�
�
()
i f.
w
��'1'O +2
-I
-: -----
"Hf
-
T\---�
I
ADP+OPj
�
The Chi molecule in the reaction center of photosystem absorbs light maximally at 700 nm, becoming Chl *.
8.9 Noncyclic Electron Transpo rt Uses Two Photosyste ms (Page 167)
' The Chl* molecule in the reaction center
The carriers of the electron transport chain are in turn reduced.
of Photosystem I passes electrons to an oxidizing agent, ferredoxin, leaving positively charged chlorophyll (Chl +). Photosystem I
2G
Electron transport chain r
I
: I
()
'0
>.
e>
Q) c W
----------------I I
:2G_ Photon
�
�
n :
�
....
[
I
:
Energy from electron flow is captured for chemiosmotic synthesis of ATP.
electron carrier passes electrons to electron deficient chlorophyll, allowing the reactions to start again.
8. 1 0 Cyclic Electron Transport Traps Light Energy as ATP (Page 168)
+
�
@
H+ from H2 0 and electron transport through the electron transport chain capture energy for the chemiosmotic synthesis of ATP.
center of photosystem II absorbs light maximally at 680 nm, becoming Chl*.
(NADPH)
?s
2G
11
1:scri tion I �==--':::::r' Genes encoding P defensive proteins t mRNA are transcribed. Translation ____
d�.�:g � ���§�
Protein
�
�
1 8.5 Cell Signaling and Defense (Page 407)
Antibodies
react with
Each B cell makes a different, specific antibody and displays it on its cell surface.
Population of specific B cells ...which stimulates the cell to divide...
This B cell makes an antibody that binds this specific antigenic determinant. .. Antigenic ,t:} determinant �
\
Antigenic determinants
(epitopes) are small portions of antigens.
Page 407 In-Text Art
Some develop into plasma cells (effector B cells) that secrete the same antibody as the parent cell.
A few develop into non-secreting memory cells that divide at a low rate, perpetuating the clone.
1 8.6 Clonal Selection in B Cells (Page 408)
232
(HAPU R 18
'''':UII:IO
Some Human Pathogens for Which Vaccines are Available INFECTIOUS AGENT
Bacteria
Bacillus anthracis Bordetella pertussis Clostridium tetani Corynebacterium diphtheriae Haemophilus influenzae Mycobacterium tuberculosis Salmonella typhi Streptococcus pneumoniae Vibrio cholerae
Adenovirus Hepatitis A Hepatitis B Influenza virus Measles virus Mumps virus Poliovirus Rabies virus Rubella virus Vaccinia virus Varicella-zoster virus
Viruses
(Page 409)
DISEASE
VACCINATED POPULATION
Anthrax Whooping cough Tetanus Diphtheria Meningitis Tuberculosis Typhoid fever Pneumonia Cholera
Those at risk in biological warfare Children and adults Children and adults Children Children All people Areas exposed to agent Elderly People in areas exposed to agent
Respiratory disease Liver disease Liver disease, cancer Flu Measles Mumps Polio Rabies German measles Smallpox Chicken pox
Military personnel Areas exposed to agent All people All people Children and adolescents Children and adolescents Children Persons exposed to agent Children Laboratory workers, military personnel Children
IMMUNOLOGY: GENE EXPRESSION AND NATURAL DEFENSE SYSTEMS
HYPOTHESIS: Injecting a foreign antigen early in development allows an animal to develop immunological tolerance to that antigen.
I� 8 to 10 weeks later, treated and untreated
M ETHOD
strain B mice mature into adults, and skin grafts from strain A mice are implanted.
I. Lymphoid cells from a strain A
mouse are injected into newbom strain B mice. Strain B control mice are not injected.
Do nor mo use of str ain A
\
RESULTS Tolerance
The treated mouse accepts strain A graft.
Treated
Str ain A mo use
p Control
.J
� ��� �� ��
Newbor n str ain B mice
No tolerance
The control mouse rejects strain A graft.
Adult str ai n B mice
CONCLUSION: Which antigens an animal recognizes as self and nonself depends on when it first encounters them.
1 8.7 Immunological Tolerance (Page 410)
233
234
CHAPTfR I8
(A)
Disulfide bonds �
(8)
1 8.9 The Structure of Immunoglobulins (Page 412)
IMMUNOLOGY: GENE EXPRESSION AND NATURAL DEFENSE SYSTEMS
235
.",;ull:8' Antibody Classes
IgG
Monomer
IgM
Pentamer
CLASS
IgD
GENERAL STRUCTURE
Monomer
IgA
Dimer
IgE
Monomer
��
�U ?()\: \
Free in blood plasma; about 80 percent of circulating antibodies Surface of B cell; free in blood plasma
Most abundant antibody in primary and secondary immune responses; crosses placenta and provides passive immunization to fetus Antigen receptor on B cell membrane; first class of antibodies released by B cells during primary response
Surface of B cell
Cell surface receptor of mature B cell; important in B cell activation Protects mucosal surfaces; prevents attachment of pathogens to epithelial cells
Secreted by plasma cells in skin and tissues lining gastrointestinal and respiratory tracts
When bound to antigens, binds to mast cells and basophils to trigger release of histamine that contributes to inflammation and some allergic responses
LOCATION
,
��
5�
��
Saliva, tears, milk, and other body secretions
(Page 412)
Antibody / Antigenic determinant
The macrophage has receptors for the constant region of the heavy chain of the antibody.
Binding of antibody to a receptor activates phagocytosis.
18.10 IgG Antibodies Promote Phagocytosis (Page 413)
FUNCTION
236
CHAPUR 18
Myeloma cells grow well in culture.
Hybridoma
A myeloma cell is fused with a B cell to form a hybridoma . •• A single hybrid om a
cell is isolated and grown in culture, and assayed for antibody. Antibody-producing hybridomas proliferate indefinitely in culture.
1 8. 1 1 Creating Hybridomas for the Production of Monoclonal Antibodies (Page 413)
�
Antigen
A macrophage takes up an .--:== antigen by phagocytosis.
Class II
protein
MHC
The macrophage breaks down the antigen into fragments.
A class II MHC protein binds an antigen fragment.
,. The MHC presents the antigen to a TH cell. A hydrophobic region anchors the chain in the plasma membrane.
18.12 A T Cell Receptor (Page 414)
receptor
1 8. 1 3 Macrophages Are Antigen-Presenting Cells (Page 415)
IMMUNOLOGY: GENE EXPRESSION AND NATURAL DEFENSE SYSTEMS
237
Antigen presenting cell PRESENTING CELL TYPE
Any cell receptor protein
ANTIGEN PRESENTED
M HC CLASS
Intracellular Class I Cytotoxic T cell protein fragment (Tel Macrophages Fragments from Class II Helper T cell and B cells extracellular proteins (TH)
1 8 . 1 4 The Interaction between T Cells and Antigen-Presenting Cells (Page 415)
T CELL TYPE
T CELL SURFACE PROTEIN
COB CD4
238
(HAPHR 18
HUMORAL IMMUNE RESPONSE
CELLULAR IMMUNE RESPONSE
ACTIVATION PHASE
ACTIVATION PHASE Class I MHC
T cell /receptor
Interleukin-1 (a cytokine) activates a TH cell.
receptor
The antigen is taken up by phagocytosis and degraded in a lysosome.
A viral protein made in an infected cell is degraded into fragments and picked up by a class I MHC protein.
A T cell receptor recognizes an antigenic fragment bound to a class I MHC protein on an infected cell.
A T cell receptor recognizes an antigenic fragment bound to a class II MHC protein on the macrophage.
EFFECTOR PHASE
EFFECTOR PHASE
Infected cell (one of many)
Cytokines activate B cell proliferation.
, A T cell receptor again recognizes an antigenic fragment bound to a class I MHC protein.
•
The binding of antigen to a specific IgM receptor triggers endocytosis, degradation, and display of the processed antigen.
A T cell receptor recognizes an antigenic fragment bound to a class II MHC protein on a B cell.
1 8. 1 5 Phases of the Humoral and Cellular Immune Responses (Page 416)
•
. . . which lyses the infected cell before the viruses can multiply.
IMMUNOLOGY: GENE EXPRESSION AND NATURAL DEFENSE SYSTEMS Genes enc oding c onstant regi on (e)
Genes enc oding variable regi on (V)
�____________--JA�______________�
�A�____________-, \
,�
____________
:
' ,
V1 , V2 . . · V_ 100
(variable) genes
DNA '1 234 . . . 100
01 O2 .. .0_30
(d iversity) genes
J1,J2.. · J6
Goining) genes
: :
2...30
The variable region for the heavy chain of a specific antibody is encoded by one V gene, one 0 gene, and one J gene. Each of these genes is taken from a pool of like genes.
The constant region is selected from another pool of genes. The number of possible combinations to make an immunoglobulin heavy chain from this set of genes is (100 V)(30 0)(6 J)(8 C) = 144,000.
1 8.1 6 Heavy-Chain Genes (Page 418)
(A) DNA rearrangement (
Constant region
Variable region A
V
Embryonic DNA
VOJ ;"o;og
(8) Transcripti on an d RNA spl ic ing
B cell
\
J segments
0
l
�
C segments
DNA V
After \I, 0, J, and C DNA segments have been joined, the resulting functional supergene is transcribed. Primary RNA transcript LI Splicing of the primary RNA transcript removes the transcripts of any introns and of any extra J genes.
t
__L.J.
---' __ --"__ -,.-
__
Spl icing
�
mRNA I��____________ V
0
J
Translat ion
�
_'_
__ ____� ��
�
�
�;
I/ ij
�
�ain g�
--- Heavy chain
1 8. 1 7 Heavy-Chain Gene Rearrangement and Splicing (Page 419)
_'
__
239
240
(HAPHR 18
Constant region
r-________-JA�________� \
DNA
DNA
mRNA
V
0 J y2p
t
region causes a new C gene to be expressed (lgG instead of IgM).
Translation 18.18 Class Switching (Page 420)
INITIAL RESPONSE: SENSITIZATION
IgE binds to receptors on mast cells or basophils.
r
I IgE antibody
B cell Mast cell
LATER RESPONSE
Mast cells quickly release histamine, resulting in an allergic reaction.
-
18.19 An Allergic Reaction (Page 421)
IMMUNOLOGY: GENE EXPRESSION AND NATURAL DEFENSE SYSTEMS
Soon after the initial HIV infection, the immune system destroys most of the virus.
As T cells are further reduced, immune function is impaired and opportunistic infections
The T cell concentration gradually falls and the HIV concentration rises.
T cell concentration
/
2
5
4
3
6
7
Years
This is the set point of low-level HIV production.
18.20 The Course of an HIV Infection (Page 422)
Bacterial skin infections;
800
Herpes simplex, Herpes zoster (viruses);
'D
oral and skin fungal infections
//
a a :0 600 '0
�
e () 'E 400 ill
Q.
!!2 Qj () I I-
Pneumocystis carinii
/Tuberculosis
�
pneumonia Cytomegalovirus � infection; lymphoma (tumor)
200
0
Kaposi's sarcoma (Skin cancer)
2 years
6 years
1 0 years
18.21 Relationship between T H Cell Count and Opportunistic Infections (Page 422)
8
g
10
241
242
(HAPHR 18
Outside of cell Viral
Inside of cell 1 8.22 Two Receptors for HIV (Page 423)
Viral envelope glycoproteins
Differential Gene upression in Development
(HAPHR
ANIMAL DEVELOPMENT
Gut cavity
�
� -
Zygote (fertilized egg)
Eight cells
�
�
�
-
Blastula (cross section)
Gastrula (cross section)
Pluteus larva
Adult sea star
PLAN T DEVELOPMENT
Seed leaves (cotyledons)
•
�
�
Zygote (fertilized egg)
Two cells
�
Octant
"Globular" embryo
"Heart" embryo
"Torpedo" embryo
Mature plant
19.1 From Fertilized Egg to Adult (Page 428)
243
244
(HAPT[RI9
{XP{RI M{NT HYPOTHESIS: The fate of the cells in an early amphibian embryo is irrevocably determined.
These cells would
Cells in this location ultimately become brain tissue. Cells here ultimately become the tissue of the notochord, a stiffening rod in the embryo.
Early frog embryo
M ETHOD
Tissue transplant
)II
Experiment 1
tissue is transplanted to the "brain" region.
Tissue destined to become part of a tadpole's skin is cut from an early embryo (donor) and transferred to another early embryo (host).
Experiment 2
tissue is transplanted to the "noto chord" region.
RESULTS
CONCLUSION: The hypothesis is rejected. Cell fates in the early embryo are not determined, but can change depending on the environment.
19.2 Developmental Potential in Early Frog Embryos (Page 429)
DIFFERENTIAL GENE EXPRESSION IN DEVELOPMENT {XP{RI M{NT HYPOTHESIS: Differentiated plant cells are totipotent and can be induced to generate all types of the plant's cells. M ETHOD
Clumps of differentiated cells are removed from the root.
GIG G0) ®
The cells are grown in a nutrient medium, where they dedifferentiate.
Root of carrot plant
A dedifferentiated cell divides . . .
:
. . and develops
� Into a mass of cells called a callus.
The callus is planted in a specialized medium with hormones, etc.
RESULTS
... A reproductively functional plant is produced.
CONCLUSION: Differentiated plant cells are totipotent.
19.3 Cloning a Plant (Page 430)
245
CHAPT{RI9
246
HYPOTHESIS: Differentiated animal cells are totipotent. METHOD
An egg is removed from a Scottish blackface ewe.
Scottish blackface sheep (#2)
, Udder cells are deprived of nutrients in culture to halt the cell cycle prior to DNA replication.
The udder cell (donor) and enucleated egg are fused.
•
Stimulating mitotic inducers causes the cell to divide.
An early embryo develops and is transplanted into a receptive ewe.
I 0---{� o
Donor nucleus (#1 )
Enucleated egg (#2)
t � t
RESULTS
Dolly, a Dorset sheep, genetically identical to #1 CONCLUSION: Differentiated animal cells are totipotent in nuclear transplant experiments.
19.4 Cloning a Mammal (Page 431)
DIFFERENTIAL GENE EXPRESSION IN DEVELOPMENT
A heart attack was induced in a female mouse, causing damage to the left ventricle of the heart,
247
Bone marrow cells were taken from an adult male mouse, The early embryo, or blastocyst, is cultured in a nutrient medium.
The outer layer collapses and the inner cell mass is freed from the embryo. Chemicals are added to disaggregate the inner cell mass into smaller clumps.
t
bone marrow cells and injected into the female's damaged heart, , In 2 weeks, the injected stem cells had helped to regenerate part of the damaged heart,
19.6 Repairing a Damaged Heart (Page 433)
Clumps of cells
@ t �
�
Each clump grows into a colony of embryonic stem cells.
, Special differentiation factors are added to colonies in separate
cells to damaged tissues.
19.7 The Potential Use of Embryonic Stem Cells in Medicine
(Page 433)
248
(HAPHR 1 9
(XP(RIM(NT HYPOTHESIS: Different regions in the fertilized egg and the embryo have different developmental fates.
A nucleus is removed from a donor (the patient) cell.
re
M ETHOD
O.....-- E99 Bottom (vegetal pole) Fertilization and cell division
The nucleus is implanted into an enucleated egg.
Enucleated
egg
e ag
" " _8 - c , _ _ _ _ _ _
�
Nucleus removed
The embryo is bisected horizontally, separating upper cells from lower cells. The egg is stimulated to divide and form a blastocyst.
, Embryonic stem cells are
--L-J.::>"J�_..J removed.
Nerve tissues
Muscle tissues
a
@
/
\
The embryo is bisected vertically, leaving each half with both upper and lower cells.
stage
I \ cells remain embryonic
Top
Bone tissues
Top
(an i mal pole)
RESULTS
Bottom cells produce abnormal larva
Two normal, but small, larvae are produced
CONCLUSION: The upper and lower halves of a sea urchin embryo differ in their developmental potential.
•
to form differentiated cells. . .
. . . which are transplanted into the original nucleus donor (the patient). 19.9 Asymmetry in the Early Sea Urchin Embryo (Page 436)
19.8 Therapeutic Cloning (Page 434)
DIFFERENTIAL GENE EXPRESSION IN DEVELOPMENT
Animal pole
Vegetal pole
t
Unequal distribution of a cytoplasmic component in a fertilized egg . . .
. . . is retained as the cell divides . . .
t . . . and establishes the fates of its descendants.
19.10 The Principle of Cytoplasmic Segregation
(Page 43 7)
The optic vesicle bulges out from the forebrain.
The optic vesicle induces overlying tissue to form the lens placode.
The optic cup forms and induces lens formation.
•• The developing lens separates
from the surface tissue and induces it to form the comea.
�
OPtiC nerve
Frog head (dorsal view)
Surface tissue
Lens placode tissue
19.11 Embryonic Inducers in the Vertebrate Eye (Page 437)
!
249
CHAPHR19
250
Anus Vulva
Eggs
The primary inducer, produced by the anchor cell, activates a gene whose products determine that cells will develop as vulval precursors rather than epidermal cells.
(8)
Anchor cell
The secondary inducer activates another gene, thus determining that cells will develop as secondary precursors.
No primary inducer to activate gene 1 . Gene 3 on
Gene 1 on Gene 2 on
!
I Secondary inducer activates gene 2
I secon dary� )-� ����� �
Gene 1 on
inducer activates gene 2
Epidermis 19.12 Induction during Vulval Development in Caenorhabditis e/egans (Page 438)
@
Gene Gene
1 on 2 on
No primary inducer to activate gene 1 . Gene 3 on
�
EpidermiS
DIFFERENTIAL GENE EXPRESSION IN DEVELOPMENT
A cell produces an inducer. •
• Inducer____ molecules •.• •• • . . � .. •, . . • • • • .. • • . . . \�-------..,. This cell receives • • • • many inducer molecules that
•
• •
Diffusion of the inducer forms a concentration gradient.
•
Inducer binding results in transcription factor translocation to the nucleus. Transcription factor binds a promoter, activating gene transcription.
DNA
•
while this cell receives very little inducer. . . .
/'�W;PtiO •
-vPromoter ::::iI= :I ==== ..
mRNA
Protein
t 1E':':5 : :!!!l!2:::J 2: t
�
•
"
'
The protein encoded by the gene stimulates cell differentiation.
19.13 Embryonic Induction (Page 439)
41 days after fertilization:
Genes for apoptosis are expressed in the tissue between the digits.
56 days after fertilization:
Apoptosis is complete. Cells of the digits have absorbed the remains of the dead cells.
19.14 Apoptosis Removes the Tissue between H uman Fingers
(Page 440)
251
252
(HAPUR 1 9
.. ...... Mature flower ...._
(A)
Genes:
A
Wild-type Arabidopsis flower
c c c c Mutation of class A: No petals or sepals; stamens and carpels instead
Mutation of class B: No petals or stamens; sepals and carpels instead
Mutation of class C: No stamens or carpels; petals and sepals instead
1
Whorl 1: sepal \
A
Early flower differentiation (meristems)
19.15 Organ Identity Genes in Arabidopsis Flowers (Page 440)
A
A
A
DIFFERENTIAL GENE EXPRESSION IN DEVELOPMENT bicoid mRNA
Bicoid mRNA is deposited by
maternal cells at the anterior end of the egg.
.l
Anterior
Posterior
Translation produces Bicoid protein, a transcription factor.
A gradient of Bicord protein results.
High concentrations of Bicoid stimulate the head-specifying genes.
1 9.1 7 Bicoid Protein Provides Positional Information (Page 443)
(B)
(A)
Maternal effect genes
determine the anterior posterior axis and induce three classes of segmentation genes. (C)
Gap genes define several broad areas and regulate . . .
. . . pair rule genes,
which refine the segment locations and regulate . . .
(0)
. . . segment polarity genes,
which determine the boundaries and anterior-posterior orientation of each segment.
Once segments are established, Hox genes define the role of each segment.
1 9 . 1 8 A Gene Cascade Controls Pattern Formation in the Drosophila Embryo (Page 443)
253
254
CHAPT{RI9
In the adult fly, this segment . . .
bithorax cluster
Antennapedia cluster A
abdA AbdB
. . . is determined by this gene.
Head
Thorax (T1 -T3)
Abdomen (A1-AS)
19.19 Hox Genes in Drosophila (Page 444)
This diagram approximates the positions of gene expression in the embryo.
Development and {volutionary (hange
(UAPHR
Drosophila (1 0 hours)
embryo
lab
Dfd
pb
Ser Antp
Ubx AbdA AbdB
(��:� ,-A--., ,-A--., '" ',," ,-A--., ,-A--., b9 b8 b7 Mouse b l b2 b3 b4 b5 b6 Hoxb (�:� �
Drosophila Hom -C
..
Mouse embryo (1 2 days)
.. " ............ ." " .......... ".
,-A--.,
Neural tube
20.1 Regulatory Genes Show Similar Expression Patterns
(Page 450)
255
(HAPHR Z O
256
Head
Thorax (T1 -T3)
Abdomen (A1 -AS)
.:::-' ======� A=-----��c=
,--- -----., ,--I � �
Drosophila embryo
In the second segment, genes are transcribed that produce large, veined wings. .-DNA pro
'''
'
-
'
" 1\ \ \ \ \ 1 \ I \ I
�;
actor
�
Wing- � forming � gene
/
Transcription
segment, Ubx protein inhibits wing gene transcription.
i
�
1
No transcription
Transcription
t
t
20.3 Segments Differentiate under Control of Genetic Switches
(Page 451)
(A) B. rostratus (terrestrial)
The digits of this adult terrestrial salamander extend past the webbing.
The webbed feet of this arboreal species resemble those of the juvenile B. rostratus.
20.4 Heterochrony Created an Arboreal Salamander (Page 452)
DEVELOPMENT AND EVOLUTIONARY CHANGE {XP{RIM{NT HYPOTH ESIS: Adding Gremlin protein (a BMP4
inhibitor) to a developing chicken foot will transform it
into a ducklike foot.
METHOD
Open chicken eggs and carefully add Gremlin-secreting beads to the webbing of embryonic chicken hind limbs. Add beads that do not contain Gremlin to other hindlimbs (controls). Close the eggs and observe limb development. RESULTS
In the hindlimbs in which Gremlin was secreted, the webbing does not undergo apoptosis, and the hindlimb resembles that of a duck. The control hindlimbs develop the normal chicken form.
CONCLUSION: Differences in gremlin gene expression cause differences in morphology, allowing duck hindlimbs to retain their webbing.
20.6 Changing the Form of an Appendage (Page 453)
257
258
(HAPHR 20
In the insect lineage, a mutation in the
Fly
Ubx gene prevents legs from forming in
the abdominal segments.
Mosquito Butterfly Moth Beetle
--'.:i:==��5:��� Springtail Shrimp Common ancestor
Spider Centipede Onychophoran
20.7 Mutation in a Hox Gene Changed the Number of Legs in Insects (Page 454)
Most arthropods have legs growing from their abdominal segments.
DEVELOPMENT AND EVOLUTIONARY CHANGE
Dry-season form In cooler temperatures, there is little distal-less protein in the pupa's wing disk.
Distal-less protein produces prominent eyespots in the adult.
Bicyclus anynana
20.8 Eyespot Development Responds to Temperature (Page 455)
259
CHAPUR Z O
260
Pterosaur
(extinct) Ulna
Bird
Phalanges (digits)
Metacarpals
20.1 2 Wings Evolved Three Times in Vertebrates (Page 458)
(HAPHR
Th� History of Lif� on (arth
1"liUtill
Half- Lives of Some Radioisotopes HALF-LIFE
RADIOISOTOPE
2 Phosphorus-32 e p) Tritium eH)
1 4.3 days 1 2.3 years
Carbon-1 4 (14C)
5,700 years
Potassium-40 (40K)
1 .3 billion years
Uranium-238 f38U)
4.5 billion years
(Page 466)
Accumulating daughter atoms
Surviving parent atoms 2 In each half-life, 1/2 of the parent atoms decay into daughter atoms.
3
4
Time (half-lives) The fraction of parent atoms remaining in the sample reveals how many half-lives have elapsed.
21.1 Radioactive Isotopes Allow Us to Date Ancient Rocks
(Page 467)
261
262
OIAPUR 11
Earth 's Geological History RELATIVE TIME SPAN
ERA
Cenozoic
Mesozoic
c ro
E
E
ro u
�
0..
Paleozoic
ONSET
PERIOD
QuaterAary
1 .8 mya 65 mya
Tertiary
U;,.UfllJ MAJOR PHYSICAL C HANGES ON EARTH
Cold/dry climatE?; repeated glaciations Continents near current positions; climate coo.\s
Cretaceous
1 45 mya
Northern continents attached; Gondwana begins to drift apart; meteorite strikes Yucatan Peninsula
Jurassic
200 mya
Two large continents form: Laurasia (north) and Gondwana (south); climate warm
Triassic
251 mya
Pangaea begins to slowly drift apart; hot/humid climate
Permian
297 mya
Continents aggregate into Pangaea; large glaciers form; dry climates form in interior of Pangaea
Carboniferous
359 mya
Climate cools; marked latitudinal climate gradients
Devonian
4 1 6 mya
Continents collide at end of period; meteorite probably strikes Earth
Silurian
444 mya
Sea levels rise; two large continents form; hot/humid climate
Ordovician
488 mya
Massive glaciation, sea level drops 50 meters
Cambrian
542 mya
02 levels approach current levels
600 mya
02 level at >5% of current level 02 level at > 1 % of current level 02 first appears in atmosphere
1 .5 bya Precambrian
3.8 bya 4.5 bya
"mya, million years ago; bya, billion years ago.
(Page 466)
Melting lithosphere provides magma that fuels volcanoes.
Rising plumes of magma push the plates apart. The cooling magma forms new crust.
21 .2 Plate Tectonics and Continental Drift (Page 468)
Where two plates collide, one is pushed under the other, generating seismic activity.
THE HISTORY OF LIFE ON EARTH
263
MAJOR EVENTS IN THE HISTORY OF LIFE
Humans evolve; many large mammals become extinct Diversification of birds,. mammals, flowering r=>lants, and insects Dinosaurs continue to diversify; flowering plants and mammals diversify; mass extinction at end of period (",76% of species disappear) Diverse dinosaurs; radiation of ray-finned fishes Early dinosaurs; first mammals; marine invertebrates diversify; first flowering plants; mass extinction at end of period (",65% of species disappear) Reptiles diversify; amphibians decline; mass extinction at end of period (",96% of species disappear) Extensive "fern" forests; first reptiles; insects diversify Fishes diversify; first insects and amphibians; mass extinction at end of period (",75% of species disappear) Jawless fishes diversify; first ray-finned fishes; plants and animals colonize land Mass extinction at end of period (",75% of species disappear) Most animal phyla present; diverse photosynthetic protists Ediacaran fauna Eukaryotes evolve; several animal phyla appear Origin of life; prokaryotes flourish
High
Qj
j?
C1l OJ UJ
Asterisks indicate times of mass extinctions of marine organisms, most of which occurred when sea levels dropped.
*
Low
Triassic
Precambrian
• Jurassic
C retaceous
Mesozoic 200 Millions of ye ars ago (my a) 21 .3 Sea Levels Have Changed Repeatedly (Page 469)
1 45
65 Quaternary
1 .8 Present
(HAPTfR Z I
264
1 00 80 � 50 c Q) OJ 30 0>-
(f) OJ >
X 0 0>C1l
'? C
Hundreds of millions of years elapsed before atmospheric oxygen levels became high enough to support eukaryotes,
10 5 3 2
Q) (f)
�
D-
'0 C Q)
� Q) D-
oxygen O
4,000 3,000 2 ,000
250
500
1 ,000
1 00
Present
Millions of years ago (mya) 21 .5 Larger Cells Need More Oxygen (Page 470)
High � ::J 1§ Q)
Large areas of Earth 's surface were covered by glaciers during these periods,
D-
E 2 c C1l Q)
E
_(f) .r: t C1l W
Low
'0
'0
.r:
::J .r:
'E
'E ::J
C
'0 ..... '0
:;::, 0 I
"0 0
Ordovician
Precambrian
Devonian P a l e oz oi c
542
488
444
416
L
Pangaea
:;::, 0 I
Carboniferous Permian
359
297
� 8
251
C
Triassic
Jurassic
Cretaceous
Tertiary
M e s oz oi c 200
Milli ons of years ag o (mya) 21 .6 Hot/Humid and Cold/Dry Conditions Have Alternated over Earth's H istory (Page 470)
1 45
�
Cer:lGz0ic 65
Quaternary
1 ,8
Present
THE HISTORY OF LIFE ON EARTH
(A)
(8)
South Pole
This group of land masses gradually moved together to form Gondwana.
21 . 1 0 Cambrian Continents and Fauna (Page 473)
21 .1 1 Cooksonia, the Earliest Known Vascular Plant (Page 474)
265
(HAPHR lJ
266
(A)
' , CarbooiIeroos Permian �
542
L2..LS
359
488
Triassic
Jurassic
297� 251� 200
Millions of years ago (mya)
' 65" ";"" 1 : 8 1
Cretacecus
MeS0z0ic
145 -
Tertlary
',�,Quaternary
' Cenozoic! , ,
,
Present
(8)
During the Devonian period, the northern and southern continents were approaching one another.
21 . 1 2 Devonian Continents and Marine Communities (Page 474)
Precambrian Cambrian Ordovician Silurian D€von�
542
488
Paleozoic 444
416
Permian
297
Triassic
251
Jurassic
cretacecus
Mesozoic 200
� """65*
Millions of years ago (mya)
21 . 1 4 A Carboniferous "Crinoid Meadow" (Page 475)
1":"8 1
Tertiary
�Quaternary
Cenozoic I ,
,"
Present
THE HISTORY OF LIFE ON EARTH Precambriani Cambrian
542
Ordovician Silurian Devonian Carboriierous
488
Paleozoic 444
416
359
�
Triassic
-;;;�-;o".
Jurassic
Cretaceous
Mesozoic 200
1 45
�
.Tert.ia . rt
e
l.
Cenozoic I'.
ouat rnary
65 = 1 '8
Present
During the Permian, Laurasia and Gondwana merged to form Pangaea.
2 1 . 1 5 Pangaea Formed in the Permian Period (Page 476)
/
Precambrian Cambrian Ordovician Silurian Devoo� Carboriieroos pe.fl11ian Triassic
600
542
488
Paleozoic . 444
416
359' �297
251 -
I Jurassic I
:O;00. . •. .. . 145
Millions of years ago (mya)
- clr . '\
21 . 1 6 Jurassic Parkland (Page 476)
Cretaceous
M e� i c
;1j", .
�
Terti . . .·aI'f
� Ouaternal'f
Cenozoic I
•.
- 65
Q u atern
aryprese nt
267
268
CHAPUR Z I
Cambrian Ordovician Silurian Devonian CMxnfaous Permian Triassic
Paleozoic 444 416
359
297- 251
Jurassic
Mesozoi 200
Millions of years ago (mya)
-"1 45
You can begin to make out the forms of what will become
_ _ _ _ ---,
Cambrian
Permian
Devonian
2 1 . 1 7 Positions of the Continents during the Cretaceous Period (Page 477)
u:';umIJ
Subdivisions of the Cenozoic Era PERIOD
EPOCH ONSET (M YA)
Quaternary
Holocenea
0.01 (-1 0,000 years ago)
Pleistocene
1 .8
Tertiary
Pliocene
5.3
Miocene
23
Oligocene
34
Eocene
55.8
Paleocene
65
liThe Holocene is also known a s the Recent.
(Page 478)
EPOCH ONSET (M YA)
The two major land masses were separated by a continuous tropical sea.
THE
� f "I .
(A) Cambrian fauna
(8) Pal e oz oic fauna
.
Trilobites
269
(C) M odern fauna
Echinoderms
'U'"
Arth"'
HISTORY OF LIFE ON EARTH
�� ;" (f �
'O d'
C'
Eocrinoids
Crinoids Cartilaginous fishes
Anthozoans
� 600 =>
£?
OJ
6
Oro E 400 '0 Qj
.0
E :t 200 Precambrian Cambrian Ordovician
Silurian Devonian P a l e oz oi c
542
488
444
416
Carboniferous
Permian
Jurassic
Cretaceous
251
cen
1 45
200
65
Quaternary
Milli on s of years ag o (mya) 21 . 1 9 Evolutionary Faunas (Page 478)
The study measured number of ribs on the rear dorsal section of the exoskeleton.
�
Nileids
Platycalymene
Cnemidopyge
"§"
ro Q) >. c
� 'E
Ogygiocarella
Nobiliasaphus
Whittardolithus
)
C')
'0
en
V"'- ro N �
e §5
*�
T O.
25 o
Flying
Mating successfully
Flying
Mating successfully
The proportion of cyanide-producing individuals increases gradually along a r-:;-------;-:;---, gradient from colder to milder winters.
CONCLUSION: Heterozygous Colias males have a mating advantage over homozygous males.
22. 1 9 A Heterozygote Mating Advantage (Page 502)
� plants not producing cyanide
Red indicates proportion of plants producing Cyanide
White indicates proportion of
22.20 Geographic Variation in a Defensive Chemical
(Page 503)
Sp�ci�s and Th�ir formation
(HAPHR
The two populations diverge genetically but are still reproductively compatible.
Increasing
t
Ql 0 c: co
Ul '5 0
� c:
0
Ql
(')
+
Daughter species A
��� ��! �
.
Interbreeding population (parent species)
we incompatibility is established.
......
�. I'
Increasing
"
Daughter species B
Time
23.2 Speciation May Be a Gradual Process (Page 510)
A barrier separates two populations. Popu lations adapt to differing environments on opposite sides of the barrier.
The barrier is removed. The populations recolonize the intervening area and mingle, but do not interbreed.
23.3 Allopatric Speciation
282
(Page 511)
SPECIES AND TH E I R FORMATION
283
Seed eaters
lBilis of seed eaters are adapteGl for harvesting and crwshing seeds. Large ground finch (Geospiza magnirostris)
North America
Large-billed finches can crush large, hard seeds.
Medium ground finch (G. fortis)
Pacific Ocean
Cocos Island Galapagos Islands
_.
--
Small ground finch (G. fuliginosa) ,
.,.
Small-billed finches cannot crush large seeds as well, but are more adept at handling small seeds.
Sharp-billed ground finch (G. difficilis)
Large cactus finch (G. conirostris)
Cactus finches are adapted to opening cactus fruits and extracting the seeds.
Cactus finch (G. scandens)
Bud eater The bud eater's heavy bill is adapted . for grasping and wrenching buds from branches.
Vegetarian finch (Platyspiza crassirostris)
Small tree finch (Camarhynchus parvulus)
ANCESTOR FINCH from Sou th American
Large tree finch (C. psittacula)
mainland
Medium tree finch
The large tree finch uses its heavy bill to twist apart wood to reach larvae inside. The small and medium tree finches and mangrove finch pick insects from leaves and branches and explore crevices for hidden prey.
(C. pauper)
Mangrove finch (C. heliobates)
The woodpecker finch uses its long beak to probe dead wood, crevices, and bark for insects.
Insect eaters
The bills of insect eaters vary because they eat different types and sizes of insects and they capture them in different ways.
Woodpecker finch (C. pal/idus)
Warbler finch (Certhidea olivacea)
23.4 Allopatric Speciation among Darwin's Finches (Page 512)
The warbler finch uses quick motions to capture insects on plant surfaces.
284
CHAPT(R l3
The difference in allele frequencies is associated with sympatric divergence.
Picture-winged Drosophila
0.55
Number of species of picture-winged Drosophila found on an island
G 0.50 c Q)
•
•
6- 0.45 .&
]l 040 (1j
� 0.35
island
�
Q)
�
23.6 Sympatric Speciation May Be Underway in Rhagoletis
Number of proposed founder events
pomonella
(Page 513)
23.5 Founder Events Lead to Allopatric Speciation (Page 513)
The diploid parent has two copies of each chromosome
Haploid gametes
Most gametes produced by the triploid hybrid are not viable because they have an incorrect number of chromosomes.
(one copy of each chromosome) Meiosis
�
Meiosis
�
Diploid gametes The tetraploid parent has four copies of each chromosome.
The F1 offspring is triploid (three copies of each chromosome)
(two copies of each chromosome)
23.7 Tetraploids Are Soon Reproductively Isolated from Diploids (Page 514)
SPEC I ES AND THEIR FORMATION
285
A tetraploid hybrid has an almost continuous range in an area around Spokane, Washington,
The range of tetraploid hybrids ( . ) is broader than that of I�""'"... . diploid parental species ( il. ), =
Idaho
23.8 Polyploids May Outperform Their Parent Species
(Page 5 1 4) (8) Aqui/egia pubescens
(A) Aquilegia formosa
1 40
(C)
1 20
g 1 00
(/) .r:::
,;,::
�
.r::: >.D
80
.l!l
'w
'5 60 15 Qj .D E::J 40 Z
20 o
A. pubescens (normal orientation)
A. formosa (upright)
A. formosa (normal orientation)
23. 1 0 Hawkmoths Favor Flowers of One Columbine Species
(Page 5 16)
286
(HAPUR 23
{XP{RI M{NT HYPOTHESIS: Phlox drummondii has red flowers
only where it is sympatric with pink-flowered P. cuspidata because having red flowers decreases interspecific hybridization. METHOD
1 . Introduce equal numbers of red- and pink-flowered P. drummondii individuals into an area with many pink-flowered P. cuspidata. 2. After the flowering season ends, assess the genetic composition of the seeds produced by P. drummondii plants of both colors. RESULTS
Of the seeds produced by pink-flowered P. drummondii, 38% were hybrids with P. cuspidata . Only 1 3% of the seeds produced by red-flowered individuals were genetic hybrids. �
..c= CIl
50
i3 .� � Ul CIl
E 25
o� c�
� .c
8:
0 '---"-----"-Pink flowers Red flowers Phlox drummondii
CONCLUSION: For Phlox drummondii, having
flowers that differ in color from those of P. cuspidata reduces the amount of interspecific hybridization.
23.1 1 Prezygotic Reproductive Barriers (Page 517)
23.1 2 Hybrid Zones May Be Long and Narrow (Page 518)
�I!!"'!!!!!II!I!II_ Common ancestor
Joppeicids (1 species)
�!!II!!!!I!!"'!!!_ Tingids (1 ,800 species)
�!!III--. Mirids (1 0,000 species) �!!IIII!II-- Isometopids (60 species)
- Herbivores - Predators on other insects
23.1 3 Dietary Shifts Can Promote Speciation (Page 519)
Th� {volution of G�n�s and G�nom�s
(HAPUR
R{S{AROI M{THOD A
Two amino acid sequences seem quite different. . . Sequence 1
• • • •
Sequence 2
• • • •
Sequence 1
• • • •
Sequence 2
• • • •
� �
• • • •
• • • •
� •- �
A
C
G
G • • • •
• • • •
G
T
T
A
A
T
T
" . but if we insert a gap in sequence 2, there is nearly complete alignment.
G C
Sequence 1
• • • •
Sequence 2
• • • •
Sequence 3
• • • •
Sequence 4
• • • •
Sequence 5
• • • •
Sequence 6
• • • •
� •- � •- � � � �
�
C
----+-
G
T
T
•
G
•
C
T C
G
C
C
C
• • • •
T
T
T
• • • •
A
A ----+- G � A
• • • •
• • • •
• • • •
G
T
A
G
Coincident substitutions
C •
G
• • • •
Multiple substitutions
A
Parallel substitutions
G
T
T
A
A
* Back
substitution
24.2 Multiple Substitutions Are Not Reflected in Pairwise Sequence Comparisons (Page 527)
Nomoorn '"O� th' d; are the number of differences. 1
Q;
.0
E:;
,
2
2
c 3 OJ
5
7
4
6
4
ar 5
5
3
6
6
4
0 c OJ :;
, Sequence number 3 4 5
� 2 5 � 1
(f)
[
----+-
T
A
Single sUbstitution
G
G
, The information in the alignment allows us to compare sequences using a similarity matrix.
[
T
G
T (
C With this alignment established, we can compare additional sequences.
•
C
G
A
A
Numbers below the diagonal line are similarities.
J
6
2
1
2
1
0
3
4
3
4
3
1
2
� 3 4 � 3
6
4
5
� 5
2
� 24.1 Amino Acid Sequence Alignment (Page 526)
287
288
CHAPUR Zit
Tuna
The number 1 indicates an invariant position in the cytochrome c molecule (i.e., all the organisms have the same amino acid in this position). Such a position is probably under strong stabilizi ng selection.
Position in sequence Number of amino acids at the position
Acidic side chains D
Aspartic acid !;] Glutamic acid
Basic side chains
Histidine Lysine Arginine Hydrophobic side chains
Phenylalanine I Isoleucine L Leucine M Methionine F
v
Y
W A
Valine Tyrosine Tryptophan Alanine
Other (;;1 �1 , Q]
N
S rn f(3;
Cysteine Proline Glutamine Asparagine Serine Threonine Glycine
20
15
25
30
'f 'f 'f 1 3 5 5 5 1 3 3 4 1 4 3 2 1 3 3 1 1 2 4 3 4 2 34 2 1 4 1 1 2 1 5 1
I I I I I I I I
F F F F F F F F F
I MKCSQC I MKCSQC VQKCAQC V Q K C' A Q C VQKCAQC VQKCAQC VQKCAQC VQKCAQC VQKCAQC
H T V 'E HTVE HTVE H T V'E HTVE HTVE HTVE HTVE H T.V E
KGGKH KGGKH KGGKH KGGKH KGGKH KGGKH KGGKH KGGKH KGGKH
Chicken, turkey G 0 I E K G K KI I Pigeon Pekin duck Snapping turtle Rattlesnake Bullfrog Tuna G O V A K G K K T Dogfish G O V E K G K K' V
F F F F F F F F
VQKCSQC VQKCSQC VQKCSQC VQKCAQC TMKCSQC VQKCAQC V Q K C. A Q C VQKCAQC
H H H H H H H H
T T T T T T T T
V V V V V C V V
KGGKHKTGPN KGGKHKTGPN KGGKHKTGPN KGGKHKTGPN KGGKHKTGPN KGGKHKVGPN NGGKHKVGPN NGGKHKTGPN
F F F F F F F F
V Q R C. A Q C H V Q R cl A Q C H VQRCAQCH KTRCE LCH K T R C{ A . E C H KTRCAECH KTKCAQCH KT KCAQCH
11 11
VE VE VE VE I E E V .D VE
Human, chimpanzee Rhesus monkey Horse Donkey Cow, pig, sheep Dog Rabbit Gray whale Gray kangaroo
Rice
10
Amino acids at positions marked by red arrowheads have side chains that interact with the heme group.
Samia cynthia (moth) Tobacco hornworm moth Screwworm fly Drosophila (fruit fly) Baker's yeast Candida krusei (yeast) Neurospora crassa (mold) Wheat Sunflower Mung bean Rice Sesame
24.3 Amino Acid Sequences of Cytochrome c (Page 528)
GO V GD V GOV G0 V G D' V GDV G0 V GOV
E E E E E E E E
KGKK KGKK KGKK KGKK KGKK KGKK KGKK KGKK
GNA E NGKK I G N A 0 N G K KI I G 0 V ' E K G K Ki I G0 V E KGKK L GSAKKGAT L GS AKKGAT L 'G 0 S K K G A N L GN P0AGAK I GO P T T GAK I G0 S KSGE K I GNPKAGEK I
T T T T T
E E E E E E E E
AGGKH AGGKH AGGKH KGGPH AGGPH NLTQ AGA H KGA
KTGPN LHG KTGPNLHG KTGPN LHG KTGPN LHG KTGPN LHG KTGPNLHG KTGPNLHG K T G P N, L H G KTGPNLNG
KVGPN KVGPN KVGPN KVGPN KVGPN K I GPA KQGPN
LHG LHG LHG LNG LHG LYG LWG L SG L L L L L L L
HG HG HG HG HG HG HG
289
THE EVOLUTION OF G ENES A N D GENOMES
Multiple amino acids at a position indicate a great deal of change. The alternative residues may be functionally equivalent. or are selected for different functions.
__
Invariant
__ __ �
35
40
45
50
55
60
65
70
__ __ __ � A __
75
80
90
85
95
1 00
1 04
T 1 1 3 1 5 1 2 2 1 6 9 2 1 7 2 2 2 3 2 2 2 6 4 4 5 4 . .. - _...... 1'""1 I A Y L KK A rn
P G T K: M I F A ' GI l rK K K 'P G T K1M I F A 'G� I K K K 'P G T K1M I F A G1 I tK K K PG PG PG PG PG PG PG PG
T T T T T T T T
K:M KIM KM KM KIM KIM KjM K1M
j
I I I I V
F A iG1 1 K FAG I K F A !.G' I �K F �jGJ I [K F !1 G. L IS
K K K K K
0
E E E E
�
K§E K�E K9E KGlE KKE E
A A A RE0 L A Rl A 0 L A R' A 0 L I A R, A O L I A R, A 0 L I A
Y Y Y Y Y Y Y Y
L L L L L L L L
I
K KA T K K A .T K K' A iT K K' A T K K A IT K KI A �T K K, A ;T K K' A �T
f
N N N N K N N N
E
E E E E E
8
RI V 01 L R A OJ L RA0 L RA0L R T NI L I A Y L .K E K T A A R Q 0' L
AYLKEST P G T KIM V F A ,G1 L lK K; A 'N E R lA O'L I A Y L K Q A T b L I A Y L IK SI A .T
AYL KTSTA A Y L ,K E S T A S' y L K E A T � I A Y L . K_E, A ,_L A
!
290
CHAPTfR 14
HYPOTHESIS: Heterogeneous environments lead to adaptive radiation, whereas homogeneous environments inhibit diversification. METHOD
One colony of Pseudomonas fluorescens (all of a single genotype) is used to inoculate many replicate cultures.
� ....
...
..
- ..
..
t
y
Half of replicate cultures are kept static, so that many different local environments may develop.
�-------'Y�--�) The other half of the cultures are shaken, to keep the environmental conditions uniform throughout the medium. RESULTS
In the shaken flasks, the ancestral morphotype persists. But in the static flasks, two new morphotypes regularly evolve, each adapted to a different local environment. Molecular analysis reveals multiple genetic causes for the similar morphotypes.
Smooth morph (ancestral)
"Wrinkly spreader"
"Fuzzy spreader"
CONCLUSION: Heterogeneous environments promote diversification.
24.4 A Heterogeneous Environment Spurs Adaptive Radiation (Page 530)
291
THE EVOLUTION OF G ENES A N D GENOMES
If:' inti/II.
(A)
Synonymous substitutions
(B)
Nonsynonymous substitutions
UUA
ACU
-
UUG
+
ACA
+
CUA
-
-
-
UUA
+
UUA
+
CD UGG
GGA
+
+
UUC
UGA
AGA
•
Stop translation
@
Similarity Matrix for Lysozyme in Mammals SPECIES
LANGUR
BABOON
HUMAN
14
18
38
32
65
14
33
39
65
37
41
64
55
64
Langur* Baboon
0
RAT
Human
a
Rat
a
Cattle*
5
a
a
a
Horse
a
a
a
a
CATTLE
a
HORSE
71
Shown above the c1iagonal line is the number of amino acid sequence
differences
between the two species being compared; below the line are the number of changes uniquely Asterisks
(*)
shared by the two species.
indicate foregut-fermenting species.
(Page 533)
in an incomplete protein. 24.5 When One N ucleotide Does or Doesn't Make a Difference
(Page 531)
H. influenzae E. coli
Yeast Rates of substitution are high where they do not affect functioning . . .
Fungus
}
Arabidopsis Drosophila
Pseudogenes
C. elegans (nematode)
Sea squirt Synonymous substitutions
Pufferfish . . . and are low where they change the amino -==:;;::::: :: :::: :: , :. acid being expressed.
Nonsynonymous substitutions o
4 3 2 Substitutions per nucleotide site per 1 0 million years
24.6 Rates of Substitution Differ (Page 531)
Plant
_'b,"""
Mouse Human 0
i
V,",b",'"
30 20 10 Number of genes (x 1 ,000)
24.8 Genome Size Varies Widely (Page 533)
(HAPHR 24
292
(A) Unequal crossing over
en Q) 15 1 00 OJ ro c 0 80 n c .2 OJ c 60 is 0 u c Q) Q) E0 40 c Q) OJ
Two different sequences of a highly repeated gene, represented by red and blue boxes, are present on a chromosome.
t:> Q)
0 0.001
Crossing over occurs between misaligned repeats on homologous chromosomes . . . . . . resulting in chromosomes with more (top) and fewer (bottom) gene copies indicated in red.
C. elegans .
'0 20 CQ) (L
1_
DNA
(B) Biased gene conversion
0.01
10 1 00 0.1 Genome size (x 1 09 base pairs)
1 000
24.9 A Large Proportion of DNA Is Noncoding (Page 534)
Damage is repaired using the sequence indicated by red (on a homologous chromosome) as a template . . . . . . resulting in one chromosome with more copies of the red sequence. 24. 1 1 Concerted Evolution (Page 536)
Myoglobin Alpha chains
Ancestral myoglobin- ---t like molecule
(a1 ' �)
Zeta chain (1;,)
Epsilon chain (e)
Gamma chains (Ay, �
443
417
a
family subunits
--
(8)
Beta chain (�)
490
}�
Myoglobin
Delta chain
Numbers indicate the estimated number of DNA sequence changes along that branch of a tree.
543
}�
354
290
248
Millions of years aQO
24. 1 0 A Globin Family Gene Tree (Page 535)
206
144
Hemoglobin
THE EVOLUTION OF GENES A N D GENOMES
Sea urchin En Ancestral engrailed gene
These species have a single engrailed gene.
Amphioxus En
Lamprey En
I Zebrafish Eng2b I
I Zebrafish Eng2a I I Chicken En2 1 I
An initial gene duplication event resulted in two paralogous engrailed genes in vertebrates.
I Mouse in2 1 Human En2
1
I Zebrafish Englb I
I Zebrafish Engla I
I Chicken En 1 I
Within orthologous groups of genes, the relationships among the species are the same (compare the relationships of En 1 genes to those of En2 genes).
24.1 2 Phylogeny of the engrailed Genes (Page 537)
I Mouse En l I Human En l
The En2 group of genes is paralogous to the En 1 group.
l
Additional gene duplications occurred in the zebrafish lineage.
293
(HAPHR l4
294
(A) peR amplification introduces new variation into the DNA population.
:£
I DNA template I
�
Selected RNA population
Transcription by T7 RNA polymerase
molecules with the highest ligation rates from the population.
(8) 1 01
1 0°
5
1 0-1
o .r::: ill 1 0-2 Q
�
3 6 1 0�
�
1 0-4
1 0-5 1 0-6
I
-o - -2 - -4 - 6' 8' -;0 -
Round
24.1 3 In Vitro Evolution of a Ribozyme (Page 539)
Reconstructing and Using Phylogenies
(HAPHR
(A)
In this book, all phylogenetic trees show the common ancestor for the group on the left; this is called the root of the tree.
The splits in branches are called nodes, and indicate a division of one lineage into two.
•
Chimpanzee
Human Common ancestor
Gorilla
Orangutan
5
15 Past
Time (millions of years ago)
The positions of the nodes on the time scale (if present) indicate the times of the corresponding speciation events.
o
y, f
Present
Branches can be rotated around any node without changing the meaning of the tree.
Chimpanzee Gorilla Orangutan
Orangutan
25.1 How to Read a Phylogenetic Tree (Page 544)
295
296
CHAPHR 25
25.2 The Bones Are Homologous; the Wings Are Not (Page 545)
" " iJlflWl
Eight Vertebrates Ordered According to Unique Shared Derived Traits DERIVED TRAIT" TAXON
JAWS
LUNGS
CLAWS OR NAILS
GIZZARD
FEATHERS
FUR
MAMMARY GLANDS
KERATINOUS SCALES
Lamprey (outgroup) Perch
+
Salamander
+
+
Lizard
+
+
+
Crocodile
+
+
+
+
Pigeon
+
+
+
+
Mouse
+
+
+
+
+
Chimpanzee
+
+
+
+
+
"A plus sign indicates the trait is present, a minus sign that it is absent.
(Page 546)
+ + +
+
RECONSTRUCTING AND USING PHYLOGEN I ES
The outgroup branches off before the basal node of the ingroup.
Lamprey
(outgroup) Common ancestor
The lamprey is designated as the outgroup.
Perch
Salamander
Derived traits are indicated along lineages in which they evolved.
Claws . or nails
s ���:�� ur
•
V
(��
• . Gizzard
�
Fur; mammary • glands
Lizard ..
������ .
..�� � Crocodile
. .. 1 !! ...1111.. .. ! ... F",thern .""_1!!!!!!!
Pigeon
___
Mouse
Chimpanzee 25.3 Inferring a Phylogenetic Tree (Page 54 7)
Sea squirt
(seen in section)
Sea squirt larvae and vertebrate embryos both have a notochord for body support.
Frog
Larva
Both the adult form of the sea squirt and the adult vertebrate lack notochords.
Adult
Vertebral
Embryo (seen in section)
25.4 A Larva Reveals Evolutionary Relationships (Page 548)
Ingroup
297
298
CHAPUR Z 5
fXPf R I MfNT HYPOTHESIS: Evolutionary history can be correctly reconstructed from the DNA sequences of living organisms using phylogenetic analysis. METHOD Select a single viral plaque at random. The virus that made this plaque is the common ancestor for the experimental lineage.
Gray dots indicate sampling points
. .. Grow viruses in the presence of a mutagen to increase the mutation rate.
\
,. Outgroup lineage
\.. �. A�. E
C lineage
·
After every 400 generations. split each ingroup lineage in two and save a sample of the ancestral lineage.
.'
l :
:
,....... F I·Ineage H lineage
e,
:
: : :�
., r�.
lineage
I
400
� ,....,. B lineage : �. �. G lineage : : 400 :: 400 �: I
� � �
Generations RESULTS
The evolutionary history of the lineages and the ancestral sequences of the viruses were both reconstructed accurately.
CONCLUSION: Phylogenetic analysis of DNA sequences can accurately reconstruct evolutionary history and ancestral sequences.
25.5 A Demonstration of the Accuracy of Phylogenetic Analysis (Page 549)
, Isolate and sequence viruses from the end points of each lineage. Subject sequences to phylogenetic analysis.
RECONSTRUCTING A N D USING PHYLOGE N I ES
(A)
Harpagochromis
Ptyochromis (8)
Arrows change color to indicate speciation during dispersal.
sp.
sp.
t
Lake Edward
Lake Kivu
Lake Eyasi
Lake Tanganyika -
Lineages derived from Lake Kivu
-
Lake Victoria lineages
25.6 Origins of the Cichlid Fishes of Lake Victoria (Page 550)
299
300
CHAPHR 2 5
L. nudatus
L. montanus
L. ciliatus
Common ancestor of Linanthus species
L. androsaceus
L. "bicolor"
L. parviflorus
L. latisectus
L. liniflorus
separate lineages, fooling taxonomists into identifying all three species as
L. acicularis
L. bicolor.
L. "bicolor"
L. jepsonii
Self-compatibility evolves
25.7 Phylogeny of a Section of the Plant Genus Linanthus
(Page 552)
L. "bicolor"
RECONSTRUCTING AND USING PHYLOG ENIES
HIV-1 (humans) SIVcpz (chimpanzees) SIVhoest (L'Hoest monkeys) SIVsun (sun-tailed monkeys) SIVmnd (mandrills) Common ancestor
SIVagm (African green monkeys) SIVsm (sooty mangabeys) HIV-2 (humans)
Hi.A6P_
SIVsyk (Sykes' monkeys)
"1#"'"
25.8 Phylogenetic Tree of Immunodeficiency Viruses (Page 553)
Amino acid positions under positive selection are represented in yellow.
25.10 Model of Hemagglutinin, a Surface Protein of Influenza
(Page 553)
30 1
302
CHAPHR 2 5
A Common ancestor of paraphyletic group B + C +
D�
B C
A paraphyletic group (pink box) includes the common ancestor and some, but not all, of the ancestor's decendants.
D
�
Common ancestor of polyphyletic group E + F + G
E
F
A polyphyletic group (yellow box) does not include the common ancestor of the group.
G H
A monophyletic group can be removed from the tree with a single "cut."
A monophyletic group (blue box) includes the common ancestor and all descendants of that ancestor.
--- J
Common ancestor of monophyletic group H + I + J
25.1 2 Monophyletic, Polyphyletic, and Para phyletic Groups (Page 555)
(HAPIfR
Bacteria and Archaea: Th� Prokaryotic Domains
The Three Domains of Life on Earth CHARACTERISTIC
If:t;uflill BACTERIA
DOMAIN ARCHAEA
EUKARYA
Membrane-enclosed nucleus
Absent
Absent
Present
Membrane-enclosed organelles
Absent
Absent
Present
Peptidoglycan in cell wall
Present
Absent
Absent
Ester-linked
Ether-linked
Ester-linked
Unbranched
Branched
Unbranched
Membrane lipids Ribosomesa
70S
70S
80S
Initiator tRNA
Formylmethionine
Methionine
Methionine
Operons
Yes
Yes
No
Plasmids
Yes
Yes
Rare
RNA polymerases
One
Oneb
Three
Ribosomes sensitive to chloramphenicol and streptomycin
Yes
No
No
Ribosomes sensitive to diphtheria toxin
No
Yes
Yes
Some are methanogens
No
Yes
No
Some fix nitrogen
Yes
Yes
No
Some conduct chlorophyll-based photosynthesis
Yes
No
Yes
"70S
ribosomes are smaller than 80S ribosomes. RNA polymerase is similar to eukaryotic polymerases.
bArchaeal
(Page 562)
303
304
(HAPHR 2 6
Archaea and Eukarya share a more recent common ancestor with each other than with Bacteria.
Origin of life
B'AGTERIA
--.J'....
_ _
-------l.�
Present
Time
Today's organisms all share this common ancestor.
26.1 The Three Domains of the Living World (Page 562)
Attraction of other organisms Free-swimming prokaryotes '--- �.
I
I-
�
Binding to surface
I
..
�
Signal molecules� " "
"
..... ..,.,... : ..... J '\ :
. .. . . .
• • •
/
"\
•
•
•
. . ",rI
•
Matrix
Signal molecules
Irreversible attachment
Single-species biofilm
\
Growth and division, formation of matrix
Mature biofilm
26.3 Forming a Biofilm (Page 564)
•
BACTERIA AND ARCHAEA: THE PROKARYOTIC DOMAINS
(A)
R{S{AR(H M{THOD
(8)
In continuous circulation mode, medium containing cells is pumped around the growth chamber loop (green) while the cells multiply. Flushing medium � Growth � medium
Valves can be adjusted to admit fresh growth medium and collect cells at a waste port.
Waste ports
26.4 Microchemostats Allow Us to Study M icrobial Dynamics (Page 564)
Gram-positive bacteria have a uniformly dense cell wall consisting primarily of peptidoglycan.
(A)
Outside of cell
'----' 1 0 11m
�:���ane ____I11'''�_ Inside of cell
I
Peri plasmic space
40 nm bacteria have a very thin peptidoglycan layer and an outer membrane.
Gram-negative
Outer t1� 1jJ3.I.( �,Mf il�iffif �;'gf �a� mtt��l1il � membrane �� � il5iM � !l!JIlmI J.j� � �1j'j of cell wall
7 � _II'i !I
pePtid0 Iycan layer
40 nm 26.5 The Gram Stain and the Bacterial Cell Wall (Page 565)
Plasma membrane
'{
lJ
Periplasmic space
305
306
(A)
CHAPHR 2 6
Axial filaments
Cell wall Outer membrane '-----'
50 nm
( 8)
Gas vesicles
26.6 Structures Associated with Prokaryote Motility (Page 566)
How Organisms Obtain Their Energy and Carbon NUTRITIONAL CATEGORY
ENERGY SOURCE
CARBON SOURCE
Photoautotrophs (found in all three domains)
Light
Carbon dioxide
Photoheterotrophs (some bacteria)
Light
Organic compounds
Chemolithotrophs (some bacteria, many archaea)
Inorganic substances
Carbon dioxide
Chemoheterotrophs (found in all three domains)
Organic compounds
Organic compounds
(Page 568)
BACTERIA AND ARCHAEA: THE PROKARYOTIC DOMAINS
307
The alga absorbs strongly in the blue and red regions, shading the bacteria living below it.
c o
eo Ul .0 co OJ >
�
Qj a:
Wavelength
(nm) Bacteria with bacteriochlorophyll can use long-wavelength light, which the algae do not absorb, for their photosynthesis.
26.9 Bacteriochlorophyll Absorbs Long-Wavelength Light (Page 568)
(A)
(8)
The "true" phylogeny of four hypothetical species is represented by the shaded tree.
(C)
core of several genes is more likely to reveal the true phylogenetic history.
�______________� A
�_____. A
B B 7"!'-_.... c c
Gene x is transferred laterally between lineages C and D.
A tree based on the sequences of a stable
D
The apparent close relationship of C and D reflects the lateral transfer of gene x, and the resulting gene tree does not reflect the true phylogeny.
26.10 Lateral Gene Transfer Complicates Phylogenetic Relationships (Page 570)
D
y��
308
CHAPUR 26
Spirochetes Chlamydias High-GC Gram-positives Cyanobacteria Common ancestor of all living organisms
Low-GC Gram-positives Proteobacteria
tARCHAEA
Crenarchaeota ..Jf � ....��� ...,��� Euryarchaeota Eukaryotes
26.11 Two Domains: A Brief Overview (Page 571)
A change of line color from green to red or blue indicates loss of the ability to photosynthesize.
�!!!!!!� Delta
} } }
�!!!!!!!III. Epsilon
Photoautotrophic ancestor of proteobacteria
Chemolithotrophs Chemoheterotrophs _ Photoautotrophs
�
AlPh'
am,
G'm�
26.19 Modes of Nutrition in the Proteobacteria (Page 575)
309
BACTERIA AND ARCHAEA: THE PROKARYOTIC DOMAINS
{XP{RIM{NT
Some archaea have long-chain hydrocarbons that span the membrane (a lipid monolayer).
HYPOTHESIS: Some prokaryotes can grow and multiply at temperatures above 120°C. METHOD
1. Seal samples of unidentified microorganisms taken from the vicinity of a thermal vent in tubes with medium containing Fe3+ as an electron acceptor. Control tubes contain the electron acceptor but no cells. 2. Hold experimental and control tubes for 10 hours in a sterilizer at 121°C. Reduction of the Fe3+ produces Fe2+ as magnetite, indicating the presence of living cells (left-hand photo). 3. In a second experiment, isolate and test for growth at various temperatures.
Glycerols at both ends
\
Other archaeal hydrocarbons fit the same template as those of bacteria and eukaryotes (a lipid bilayer).
�,�,�/�/���
/
Glycerols at one end only 26.22 Membrane Architecture in Archaea (Page 576)
RESULTS
30 1!! 25 ::J o
£. 20 OJ E :;::0 c o
15
� 10 OJ
m
(')
o
II
5 80
H
I
-C-O-C
I
90 100 110 120 130 Temperature (0C)
H
Page 576 In-Text Art (1) The iron-containing solids were attracted to a magnet only in those tubes that contained living cells.
Cells multiplied most rapidly at about 105°e but divided about once a day even at 121°e.
CONCLUSION: Some organisms in the sample multiplied at 121°C, the highest temperature yet known to allow growth of an organism.
26.21 What Is the Highest Temperature an Organism Can Tolerate? (Page 576)
H
I
H
I
-C-O-C-
I
H
Page 576 In-Text Art (2)
I
H
Th� Origin and Oiv�rsifi(ation of th� {ukaryot�s
(HAPHR
(A)
EVENTS IN HUMAN
EVENTS IN MOSQUITO After a mosquito ingests blood, male and female gametocytes develop into gametes, which fuse.
The resulting zygote enters the mosquito's gut wall and forms a cyst.
I'\=������ I
They also invade red blood cells, grow and divide, and lyse the cells. Eventually, some merozoites develop into male and female gametocytes.
�11l!I'I!
��=:""I____ II !,,: �::":�_!f\!.!'I! :: Ift!! I\'lI"-� 1
____
27.3 The Life Cycle of the Malarial Parasite (Page 586)
310
48-hour cycles of invasion, lysis, and reinvasion cause the characteristic fevers and chills of the host victim.
THE ORIGIN AND DIVERSIFICATION OF THE EUKARYOTES
1f.';II*l11
Major Eukaryote Clades ATIRIBUTES
EXAMPLE (GENUS)
Haptophytes
Unicellular, often with calcium carbonate scales
Emiliania
Alveolates
Sac-like structures beneath plasma membrane
CLADE
311
Chromalveolates
Apicomplexans
Apical complex for penetration of host
Plasmodium
Dinoflagellates
Pigments give golden-brown color
Gonyaulax
Ciliates
Cilia; two types of nuclei
Paramecium
Hairy and smooth flagella
Stramenopiles Brown algae
Multicellular; marine; photosynthetic
Diatoms
Unicellular; photosynthetic; two-part cell walls
Thalassiosira
Oomycetes
Mostly coenocytic; heterotrophic
Saprolegnia
Glaucophytes
Peptidoglycan in chloroplasts
Cyanophora
Red algae
No flagella; chlorophyll a and c; phycoerythrin
Chondrus
Macrocystis
Plantae
Chlorophytes
Chlorophyll a and b
Ulva
*Land plants (Chs. 28-29)
Chlorophyll a and b; protected embryo
Ginkgo
Charophytes
Chlorophyll
Chara
a and b; mitotic spindle oriented as in land plants
Excavates Diplomonads
No mitochondria; two nuclei; flagella
Giardia
Parabasalids
No mitochondria; flagella and undulating membrane
Trichomonas
Heteroloboseans
Can transform between amoeboid and flagellate stages
Naegleria
Euglenids
Flagella; spiral strips of protein support cell surface
Euglena
Kinetoplastids
Kinetoplast within mitochondrion
Trypanosoma
Cercozoans
Threadlike pseudopods
Cercomonas
Foraminiferans
Long, branched pseudopods; calcium carbonate shells
Globigerina
Radiolarians
Glassy endoskeleton; thin, stiff pseudopods
Astrolithium
Rhizaria
Unikonts Single, posterior flagellum
Opisthokonts *Fungi (Ch.
30)
Choanoflagellates *Animals (Chs.
31-33)
Amoebozoans
Heterotrophs that feed by absorption
Penicillium
Resemble sponge cells; heterotrophic; with flagella
Choanoeca
Heterotrophs that feed by ingestion
Drosophila
Amoebas with lobe-shaped pseudopods
Loboseans
Feed individually
Amoeba
Plasmodial slime molds
Form coenocytic feeding bodies
Physarum
Cellular slime molds
Cells retain their identity in pseudoplasmodium
Dictyostelium
'Clades marked with an asterisk are made up of multicellular organisms and are discussed in the chapters indicated. All other groups listed are treated here as microbial eukaryotes (often known as protists).
(Page 584)
312
Plasma
(HAPHR Z1
Infolding of the plasma membrane adds surface area without increasing the cell's volume.
�.r
. "." . . ---�:'::�� ::W'"� rokaryotic
Rlbosomes'�=_'
.
The pmtoct;� wall was lost.
..
. .
..
'
.
.
Infolding Increased the surface area (see Figure 27.6).
'.
.
.
.
.
Internal membranes studded with ribosomes formed. Cytoskeleton (microfilament :,,�====-.L: and microtubules) formed. -
27.6 Membrane Infolding (Page 588)
/ DeveloPing
���='
As DNA attached to the membrane of an infolded vesicle, a precursor of a nucleus formed. Microtubules from the cytoskeleton formed eukaryotic flagellum, enabling propulsion.
Early digestive vacuoles evolved into Iysosomes using enzymes from the early endoplasmic reticulum.
Mitochondria formed through endosymbiosis with a proteobacterium.
Endosymbiosis with cyanobacteria led to the development of chloroplasts, which supplied the cell with the means to manufacture materials using solar energy (see Figure 27.8).
27.7 From Prokaryotic Cell to Eukaryotic Cell (Page 589)
flagellum
THE ORIGIN AND DIVERSIFICATION OF THE EUKARYOTES
Cya noba cterium outer membrane
(8)
Secondary endosymbiosis
1 A trace of the engulfed cell's nucleus is retained in some groups.
,---*-- Host membrane
(from endocytosis)
�---1=- Engulfed cell's plasma membrane The engulfed cell's plasma membrane has been lost in euglenids and dinoflagellates.
27.8 Endosymbiotic Events in the Family Tree of Chloroplasts (Page 590)
313
CHAPUR Z7
314
Inside of cell
V Cilia Outside of cell Water passes from the cytoplasm to radiating canals and to the central vacuole . . .
27.10 Contractile Vacuoles Bail Out Excess Water (Page 592)
HYPOTHESIS: Paramecium digests its food by making food vacuoles acidic. METHOD
Paramecia are fed yeast cells that are stained with Congo red, a pH indicator.
RESULTS
Stained yeast cells
vacuole has become acidic, which helps digest the yeast cells.
As products of digestion move into the cytosol, the pH increases in the vacuole. The dye becomes red again.
CONCLUSION: Acidification of the food vacuoles assists digestion.
27.11 Food Vacuoles Handle Digestion and Excretion (Page 592)
THE ORIGIN AND DIVERSIFICATION OF THE EUKARYOTES
315
Macronucleus
Micronucleus
•• Two paramecia conjugate; I� Three of the four haploid all but one micronucleus in each cell disintegrate. The remaining micronucleus undergoes meiosis.
micronuclei disintegrate; the remaining micronucleus undergoes mitosis.
E� The paramecia donate
micronuclei to each other. The macronuclei disintegrate.
E'. The micronuclei in each cell-each genetically different-fuse.
27.13 Paramecia Achieve Genetic Recombination by Conjugating (Page 594)
� ; �� � O\I Multicellular
Spores germinate and divide to form the haploid gametophyte.
•
The sporophyte produces haploid spores by meiosis.
or
M;lo,;,
:�
€ifi1;ii
o
(n
(gametophyte)
I M;I
Haploid gametes are produced by mitosis.
HAPLOID (n)
I Mitosis I Multicellular The zygote develops into a diploid sporophyte.
diploid organism (2n) (sporophyte)
27.14 Alternation of Generations (Page 594)
/
Gametes fuse to form a zygote.
�� The new diploid micronuclei
divide mitotically, eventually giving rise to a macronucleus and the appropriate number of micronuclei.
CHAPHR Z7
316
Fusing gametes
Haploid spores DIPLOID (2n)
The diploid sporophytes and haploid gametophytes look alike-the life cycle is isomorphic.
Diploid
zygote
,�,
Diploid sporophyte
.
'
� ..-
27.15 An Isomorphic Life Cycle (Page 595)
(2n)
THE ORIGIN AND DIVERSIFICATION OF THE EUKARYOTES
Some gametophyte cells can divide mitotically to form zoospores. HAPLOID (n)
\
DIPLOID (2n)
Zygote (2n) The zygote is the only diploid cell in the haplontic life cycle.
New gametophyte (n)
27.16 A Haplontic Life Cycle (Page 595)
��} --y 11I"i'r.'f1r:t'rn1IF.tm:1
1lml'iTi'in
'.�
Page 596 In-Text Art
�
0 >2. ro (j)
317
318
UIAPHR Z7
Apicomplexans Dinoflagellates Ciliates Brown algae Diatoms Oomycetes Haptophytes Glaucophytes
}i H
Chromalveolates
Red algae Plantae
Chlorophytes Land plants Charophytes Diplomonads Parabasalids
Excavates
Heteroloboseans Common ancestor of all eukaryotes
Euglenids Kinetoplastids Cercozoans Foraminiferans Radiolarians Fungi Choanoflagellates Animals Loboseans Plasmodial slime molds Cellular slime molds
27.17 Major Eukaryote Groups in an Evolutionary Context (Page 597)
H H
}
Rh;,,,;,
Unikonts
THE ORIGIN AND DIVERSIFICATION OF THE EUKARYOTES
Micronuclei function in
vacuole I
groove
27.20 Anatomy of Paramecium (Page 599)
{XP{RIM{NT Page 600 In-Text Art
HYPOTHESIS: Copepods fail to flourish during a diatom bloom because of the toxicity of the diatoms. I
METHOD
Female copepods are fed for 10 days on either the diatom Skeleto nema costatum or a nontoxic diet of dinoflagellates (control) . 2. Eggs and newly hatched larvae are counted each day. 1.
•
100 � 80 'D Q) .r: 0 60 co .r: 40 (fJ OJ OJ 20 w 0
females
Diatom-fed females
0
2
4
6
Days
8
10
CONCLUSION: Toxicity is a plausible explanation for the failure of copepods to flourish during a diatom bloom.
27.22 Why Don't Copepods Flourish During Diatom Blooms? (Page 600)
•
. •
-.... . .
RESULTS
Although almost all eggs of the control group hatched each day, fewer and fewer of the eggs from the diatom-fed females hatched as the experiment progressed.
•
Page 602 In-Text Art
319
OIAPHR n
320
Photosynthetic chloroplasts are prominent features in a typical Euglena cell.
27.28 A Photosynthetic Euglenid (Page 604)
11;1;1,.,10 A Comparison of Three Kinetoplastid Trypanosomes TRYPANOSOMA BRUCEI
TRYPANOSOMA CRUZI
LEISHMANIA MAJOR
Human disease
Sleeping sickness
Chagas' disease
Leishmaniasis
1 nsect vector
Tsetse fly
Assassin bug
Sand fly
Vaccine or effective cure
None
None
None
Strategy for survival
Changes surface recognition molecules frequently
Causes changes in surface recognition molecules on host cell
Reduces effectiveness of macrophage hosts
Site in human body
Bloodstream; attacks nerve tissue in final stages
Enters cells, especially muscle cells
Enters cells, primarily macrophages
Deaths per year
>50,000
43,000
60,000 (?)
(Page
604)
6,·
,-------1 Fungi
,-�II'I·I,�·,=·m·m·1 Animals
.. -. - .....
Page 604 In-Text Art
Page 605 In-Text Art
}
0
I
Plants without S��ds: from S�a to Land
(HAPHR
Ance�tral organism
-flr 1
•
Chlorophyll b; , starch storage
Red algae
r '
-
,�
Other green algae
I
-'
Other green algae
Encasement of egg
�
Coleochaetales (green algae) Charales (green algae)
Embryo; cuticle; multicellular ... tz"' . !1!!!��_____1III!1II!I!I sporophyte Land plants (embryophytes)
Green plants
� �
Streptophytes
28.1 What Is a Plant? (Page 612)
321
(HAPUR l8
322
0I,:uW):81 Classification of Land Plants GROUP
COMMON NAME
CHARACTERISTICS
Liverworts
No filamentous stage; gametophyte flat
NONVASCULAR PLANTS Hepatophyta Anthocerophyta
Hornworts
Embedded archegonia; sporophyte grows basally (from the ground)
Bryophyta
Mosses
Filamentous stage; sporophyte grows apically (from the tip)
Lycophyta
Club mosses and allies
Microphylls in spirals; sporangia in leaf axils
Pteridophyta
Horsetails, whisk ferns, ferns
Differentiation between main stem and side branches (overtopping growth)
Cycads
Compound leaves; swimming sperm; seeds on modified leaves
VASCULAR PLANTS
SEED PLANTS Gymnosperms Cycadophyta Ginkgophyta
Ginkgo
Deciduous; fan-shaped leaves; swimming sperm
Gnetophyta
Gnetophytes
Vessels in vascular tissue; opposite, simple leaves
Coniferophyta
Conifers
Seeds in cones; needle-like or scale-like leaves
Flowering plants
Endosperm; carpels; gametophytes much reduced; seeds within fruit
Angiosperms
Note: No extinct groups are included in this classification.
(Page 612)
� � Multicellular gametophyte
Mitosis
Mitosis
Spore
Gametes
HAPLOID(n) DIPLOID (2n)
Zygote
Multicellular sporophyte
� �
28.4 Alternation of Generations in Plants (Page 614)
PLANTS WITHOUT SEEDS: FROM SEA TO LAND
323
Antheridium (n) Germinating spore
HAPLOID (n) Gametophyte generation
Fertilization in nontracheophytes requires water so that sperm can swim to eggs.
DIPLOID (2n) Sporophyte generation
/ SporoPhyte (2n)
Sporangium
The sporophyte is attached to and nutritionally dependent on the gametophyte.
28.5 A Moss Life Cycle (Page 615)
AnthffkJ'"m �I
/
Embryo (2n)
Archegonium (n)
324
CHAPHR Z8
{XP{RIM{NT HYPOTHESIS: Ancient microfossils, predating the earliest known nonvascular plant fossils, could be fragments of ancient liverworts. METHOD
1. Investigators allowed liverworts to rot in soil or subjected them to high-temperature acid treatment, then examined the degraded material by light and scanning electron microscopy. 2.
They compared images of the degraded material with those of microfossils from ancient rocks. RESULTS
Sheets of decay-resistant cells from the lower surface of the degraded liverworts resembled some cell-sheet microfossils, showing rosette-like groupings of cells around "pores."
Resistant fragments of liverwort rhizoids resembled some tubular microfossils. CONCLUSION: The ancient microfossils may be fragments of liverworts.
28.6 Mimicking a Microfossil (Page 616)
PLANTS WITHOUT SEEDS: FROM SEA TO LAND
Liverworts Common ancestor of land plants
Hornworts
Mosses
Club mosses
Horsetails
Whisk ferns
s�''-.{
Most ferns
t�
�
Gymnosperms
Flowers, carpels, •• triploid endosperm Flowering plants
,OJ =>
1itf
� 'fi
325
CL D 0;=> en CD 3
0-
:2 CD 6: D0:::r � CD (j)
--
Garden 2
.
if
h\
.
@I
:
,.
•.
'
"
II
'."
� ,
Before
2' ::J
......
.
After
.
(j)tg OJ
"�
U>
0. CD (3 ::J 3 1\) ..
,
Before
Q.
� ::r
�,Mm . _
i" · '?
. ..
::J
'
I
After
Force-feeding (1a days)
Fungus tested:
Incompatibility:
...... Fungus 1
a
...... Fungus 2
5
=
Complete compatibility
=
Complete incompatibility
CONCLUSION: Foreign fungi are deterred by substances produced by the fungus an ant eats, not by the ants themselves.
30.11 Keeping Fungal Interlopers Away
(Page 658)
FUNGI: RECYCLERS, PATHOGENS, PARASITES, AND PLANT PARTNERS
ASEXUAL REPRODUCTION
Mycelium (n)
I
;�
Mating type
Mating type -
�
+
M O
Spores (n)
t
Plasmogamy
HAPLOID (n)
(fusion of cytoplasm)
�
Spore-producing structure (n)
ImlWi
\
Zygote (2n)
SEXUAL REPRODUCTION
DIPLOID (2n)
DIKARYOTIC (n+n)
,
J
Dikaryotic mycelium (n + n)
Karyogamy (fusion of nuclei)
..,
,ijihltjiii.!••
/
30.12 Asexual and Sexual Reproduction in a Fungal Life Cycle
(Page 659)
341
(HAPHR 30
342
(A) Chytrids The life cycle of the aquatic chytrids features alternation of generations. They have no dikaryotic stage.
'------'
-30 l!m
HAPLOID (n) Multicellular diploid chytrid
(2n)
DIPLOID (2n)
(I
Female __ gamete
(n)
� \ Male
�
�
gamete
(n)
Hypha of + mating type
(8) Zygomycetes
I .. "
The zygomycete sporangium contains haploid nuclei that are incorporated into spores.
\
HAPLOID (n)
DIPLOID (2n) p
Rhizopus st% nifer Zygosporangium
....aum. Karyogamy
30.13 Sexual Life Cycles Vary among Different Groups of Fungi
(Page 660)
"J
am,
FUNGI: RECYCLERS, PATHOGENS, PARASITES, AND PLANT PARTNERS
..f) .r / /
(C) Ascomycetes _... .� __
The products of meiosis in ascomycetes are borne in a microscopic sac called an ascus. The fleshy fruiting bodies consist of both dikaryotic and haploid hyphae.
Bill
(p
�
� ,
� �� (J61 HaPloid :tli hyphae (n) "1
(D) Basidiomycetes In basidiomycetes the products of meiosis
are borne exposed on pedestals called basidia. Fruiting bodies consist solely of dikaryotic hyphae, and the dikaryotic phase can last a long time.
+M'b"9
�
If}
I/
�
�
-Matin
£)
$ . .
-G)
""
Dikaryotic mycelium (n + n)
HAPLOID
(n)
DIKARYOTIC
(n+n)
DIPLOID
(2n)
�
Gills lined �{ I, . with basidia
,
r-...... Developing
basidium (n + n)
Basidium
344
CHAPUR 30
(4)
/
....
I Hyphae �
(n)
On barberry ....
.. On wheat ....
HAPLOID (n)
.. DIPLOID (2n)
DIKARYOTIC (n+n) Summer hyphae
(n +n) lUr ��\" )l�( n+n)
edospores
Asexual reproduction 30.14 Fungal Life Cycles Can Be Very Complex
(Page 662)
Page 663 In-Text Art
O:Ii"WI,11 A Classification of the Fungi GROUP
COMMON NAME
FEATURES
EXAMPLES
Chytridiomycetes
Chytrids
Aquatic; zoospores have flagella
Allomyces
Zygomycetes
Conjugating fungi
Zygosporangium; no regularly occurring septa; usually no fleshy fruiting body
Rhizopus
Glomeromycetes
Mycorrhizal fungi
Form arbuscular mycorrhizae on plant roots
Glomus
Ascomycetes
Sac fungi
Ascus; perforated septa
Neurospora
Basidiomycetes
Club fungi
Basidium; perforated septa
Armillariella
(Page 664)
FUNGI: RECYCLERS, PATHOGENS, PARASITES, AND PLANT PARTNERS
Page 664 In-Text Art
Page 665 In-Text Art (1)
Page 665 In-Text Art (2)
Page 667 In-Text Art
345
("APUR
Animal Origins and th� bolution of Body Plans
Glass sponges
Common ancestor
Sponges (Chapter 31)
Demosponges
Calcareous sponges
Ctenophores Diploblastic animals (Chapter 31)
Cnidarians PROTOSTOMES (Chapter 32)
Arrow worms
�
Lophotrochozoans
ECdYSOZO�ns DEUTEROSTOMES (Chapter 33)
Echinoderms symmetry Hemichordates
• Notochord 'Chordates
31.1 A Current Phylogenetic Tree of Animals
346
(Page 672)
l;fl
Bilaterians (triploblastic)
ANIMAL ORIGINS AND THE EVOLUTION OF BODY PLANS
347
Any plane along the main body axis of this sea anemone (a cnidarian) divides the animal
(A) Radial symmetry
into similar halves.
A single plane through the anterior-posterior midline
(B) Bilateral symmetry
divides vertebrates such as fish into mirror-image halves.
Lateral
Lateral
(right)
(left)
31.3 Body Symmetry
(Page 674) ----
(B) Pseudocoelomate (roundworm)
(A) Acoelomate (flatworm)
-------
(C) Coelomate (earthworm)
Internal organ Peritoneum (mesoderm) Internal �==-----
Coelom (cavity) Muscle
organs
(mesoderm)
Mesenchyme
Ectoderm The pseudocoel is lined with Acoelomates do not have
mesoderm, but no mesoderm
The coelom and the internal organs
enclosed body cavities.
surrounds the internal organs.
are surrounded by mesoderm.
31.4 Animal Body Cavities
(Page 675)
348
(HAPUR 31
Water out via osculum
Water and food particles
Pore
31.7 Even Sessile Filter Feeders Expend Energy
(Page 677) Portuguese man-of-war
(Physalia physalis)
Cnidocytes
______
Once discharged, stylets and spines on the nematocyst
�)!!I!IJ��
anchor it to the prey,
Empty
nematocyst
OOPWI',
Everted
Uncoiled Stylet
Nucleus
\.
y Cnidocyte
Spines
(barb)
)
Base
nematocyst
of tube
tube
\.�-----�y----� Nematocyst
31.10 Nematocysts Are Potent Weapons
(Page 679)
ANIMAL ORIGINS AND THE EVOLUTION OF BODY PLANS
(A) Trochophore
Mouth
(8) Nauplius Antennule
31.12 Planktonic Larval Forms of Marine Animals
(Page 680)
349
350
UIAPUR 31
•
The zygote, which has developed in a host mammal's gut, is passed with its feces.
The fish is eaten by a mammalian host; the tapeworm matures.
The perch is eaten
The embryo
Third larval stage
develops in water.
by a larger fish.
Second larval stage First larval stage (free-swimming) Second intermediate hosts (fish)
•
The larva moves to the muscles of the perch.
, The free-swimming first The tapeworm develops into the second larval stage and is passed on when a perch eats the copepod.
31.15 Reaching a New Host by a Complex Route
(Page 682)
intermediate host (copepod)
larval stage is ingested by a copepod.
ANIMAL ORIGINS AND THE EVOLUTION OF BODY PLANS
351
""iuslll Summary of Living Members of the Major Groups of Animals APPROXIMATE NUMBER OF LIVING SPECIES DESCRIBED Glass sponges
500
Demosponges
7,000
Calcareous sponges Ctenophores Cnidarians
MAJOR GROUPS
100 Anthozoans: Corals, sea Hydrozoans: Hydras and hydroids Scyphozoans: Jellyfishes
PROTOSTOMES
Flatworms
150 100 16 320
Horsehair worms
25,000
Nematodes Onychophorans
150
Tardigrades
800
Arthropods: 50,000
Crustaceans 100 Hexapods
Lophotrochozoans Ectoprocts
Kinorhynchs Loriciferans Priapulids
anemones
Arrow worms
4,500 25,000
Free-living flatworms; flukes and
1,000,000
1,800
Ribbon worms
1,000
Phoronids Brachiopods Annelids
14,000
Millipedes, centipedes
89,000
Horseshoe crabs, arachnids (scorpions, harvestmen, spiders, mites, ticks)
DEUTEROSTOMES Echinoderms
Hemichordates
335 Polychaetes (all marine)
95
Acorn worms and pterobranchs
Chordates
55,000
Urochordates: Sea squirts Cephalochordates: Lancelets
freshwater worms, leeches 95,000
Crinoids (sea lilies and feather stars); brittle stars; sea stars; sea daisies; sea urchins; sea cucumbers
Clitellates: Earthworms,
Mollusks
7,000
20
16,500
Insects and relatives
Myriapods
monogeneans (ectoparasites of fishes)
Crabs, shrimps, lobsters, barnacles, copepods
Chelicerates
tapeworms (all parasitic);
Rotifers
MAJOR GROUPS
Ecdysozoans
500
11,000
APPROXIMATE NUMBER OF LIVING SPECIES DESCRIBED
Agnathans: Lampreys,
Monoplacophorans
hagfishes
Chitons
Cartilaginous fishes
Bivalves: Clams, oysters, mussels
Ray-finned fishes
Gastropods: Snails, slugs, limpets
Lobe-finned fishes Amphibians
Cephalopods: Squids, octopuses,
Reptiles (including birds)
nautiloids
Mammals
(Page 683)
Glass sponges Demosponges Calcareous sponges
.. Calcareous sponges Eumelazoans
Page 683 In-Text Art
Page 684 In-Text Art
352
(HAPUR 31
(A)
(8) Mnemiopsis
sp.
Mouth
31.17 Comb Jellies Feed with Tentacless As the positions of the mouth and tentacles indicate, the medusa is
Planula larvae are
"upside-down"
products of sexual
from the polyp
reproduction.
or vice versa.
Young medusa (oral surface)
Medusae bud from the polyp.
31.18 The Cnidarian Life Cycle Has Two Stages
(Page 685)
(Page 685)
ANIMAL ORIGINS AND THE EVOLUTION OF BODY PLANS
Glass sponges Demosponges Calcareous sponges Ctenophores
Page 685 In-Text Art
.::'::'
\ > :' .� �
Medusae develop asexually
100 the
O P hydrozoan
Obelia
"'�g'" "
P
O
"
.
,
are
M 'd O .
,
..
Oral surface of medusa (enlarged)
�
interconnected and share a
gastrovascular cavity.
:��ilized Planula
O
�
Sperm
/� '-------... Eggs produced by
medusae are fertilized in the open water by sperm produced by other medusae. and grow into polyps.
31.21 Hydrozoans Often Have Colonial Polyps
(Page 687)
353
Protostome Animals
CHAPTfR
..
Arrow worms
Common ancestor
ECDYSOZOANS
32.1 A Current Phylogenetic Tree of Protostomes
354
(Page 692)
� �
PROTOSTOME ANIMALS
Anatomical Characteristics of Some Major Protosto
�
e GroupsB
GROUP
BODY CAVITY
DIGESTIVE TRACT
CIRCUl�TORY SYSTEM
Arrow worms
Coelom
Complete
None
I
LOPHOTROCHOZOANS Flatworms
None
Dead-end sac
None
Rotifers
Pseudocoelom
Complete
None
Ectoprocts
Coelom
Complete
None
Brachiopods
Coelom
Complete in most
Open
Phoronids
Coelom
Complete
Closed
Ribbon worms
Coelom
Complete
Closed
Annelids
Coelom
Complete
Closed or open
Mollusks
Reduced coelom
Complete
Open ej (L O 0
600 400 200
0
(Page 773)
Stoma closed
Stoma open
CONCLUSION: K+ concentration within the guard cells surrounding an open stoma was much greater than that in the guard cells surrounding a closed stoma.
35.10 Measuring Tiny Amounts of Potassium in Guard Cells
(Page 774)
TRANSPORT IN PLANTS
Organic solutes accumulate in the phloem above the girdle, causing swelling.
35.11 Gi rdling Blocks Translocation in the Phloem (Page 775)
Source celis load sucrose
Phloem
...so water is taken up from xylem vessels by osmosis, raising the pressure potential in the sieve tubes. __ =---_-' .... Intemal pressure
differences drive the sap down the sieve tube to
Sucrose is unloaded into
35.13 The Pressure Flow Model (Page 776)
U:';UWOII Mechanisms of Sap Flow in Plant Vascular Tissues XYLEM
PHLOEM
Driving force for bulk flow
Transpiration from leaves
Active transport of sucrose at source
Site of bulk flow
Non-living vessel elements
Living sieve tube elements
and tracheids (cohesion) Pressure potential in sap
(Page 776)
Negative (pull from top; tension)
Positive (push from source; pressure)
393
Plant Nutrition
(HAPHR
•,, ;)'sltlll .
Mineral Elements Required by Plants ABSORBED FORM
MAJOR FUNCTIONS
Nitrogen (N)
N03- and NH4+
In proteins, nucleic acids, etc.
Phosphorus (P)
H P04- and HPO/2 K+
In nucleic acids, ATP, phospholipids, etc.
ELEMENT MACRONUTRIENTS
Potassium
(K)
Enzyme activation; water balance; ion balance; stomatal opening
Sulfur (S)
SO�-
In proteins and coenzymes
Calcium (Ca)
Ca2+
Affects the cytoskeleton, membranes, and many enzymes; second messenger
Magnesium (Mg)
Mg2+
In chlorophyll; required by many enzymes; stabilizes ribosomes
3 Fe2+ and Fe +
In active site of many redox enzymes and electron carriers; chlorophyll synthesis
Chlorine (CI)
CI-
Photosynthesis; ion balance
Manganese (Mn)
Mn2+
Activation of many enzymes
Boron (B)
B(OH)3
Possibly carbohydrate transport (poorly understood)
Zinc (Zn)
Zn2+
Enzyme activation; auxin synthesis
MICRONUTRIENTS Iron (Fe)
Copper (Cu)
Cu2+
In active site of many redox enzymes and electron carriers
Nickel (Ni)
Ni2+
Activation of one enzyme
Molybdenum (Mo)
MoO/-
Nitrate reduction
(Page 782)
394
PLANT NUTRITION
395
.",;JIWI$ Some Mineral Deficiencies in Plants DEFICIENCY
HYPOTHESIS: Nickel is an essential element for a
SYMPTOMS
Calcium
Growing points die back; young leaves are yellow and crinkly
Iron
Young leaves are white or yellow
plant to complete its life cycle.
METHOD
Manganese
Younger leaves are pale with green veins
1 . Grow barley plants for 3 generations in nutrient solutions containing 0, 0.6, and 1.0 �MNiS04. 2. Harvest seeds from 5-6 third-generation plants in each
Nitrogen
Oldest leaves turn yellow and die prematurely; plant is stunted
3. Determine the nickel concentration in seeds from each
Phosphorus
Plant is dark green with purple veins and is stunted
4. Germinate other seeds from the same plants and plot
Potassium
Older leaves have dead edges
Sulfur
Young leaves are yellow to white with yellow veins
Zinc
Young leaves are abnormally small; older leaves
Magnesium
Older leaves have yellow in stripes between veins
of the groups. plant. the success of germination against nickel concentration.
have many dead spots
RESULTS There was a positive correlation between seed germination and seed nickel concentration. There was no germination at the lowest nickel concentration.
(Page 783) 100 c 0
:g c E
..
• •
80
•
0 �MNiS04
•
0.6 �MNiS04
•
1.0 �MNiS04
Qj 60 OJ
C
Q)
e
Q) 0..
40 20
50
R{S{ARCIl M{TIlOD
100
150 200
250
Nickel concentration (nanograms per gram)
METHOD Grow seedlings in a medium that lacks the element in question
CONCLUSION: Barley seeds from nickel-free
(in this case, nitrogen)
plants require nickel in order to germinate, and thereby complete the life cycle.
36.3 Is Nickel an Essential Element for Plant Growth? (Page 785)
RESULTS
1
36.2 Identifying Essential Elements for Plants (Page 784)
396
CHAPUR 36
Organic
Root
36.4 The Complexity of Soil
(Page 785)
Mineral cations are released
�
into the soil
�
solution.
The cations are exchanged for hydrogen ions obtained from carbonic acid
36.6 Ion Exchange
(Page 787)
(H2C03) or from the plant itself.
PLANT NUTRITION
The final products-two molecules
A reducing agent transfers The enzyme nitrogenase binds a molecule of nitrogen gas.
397
of ammonia-are released, freeing
three successive pairs of
the nitrogenase to bind another N2
hydrogen atoms to N2.
molecule.
r�------�A�--� Substrate:
2
Nitrogen gas (N2)
2 H
� Reduction Enzyme: Nitrogenase
Reduction
Reduction
Enzyme binds substrate
36.8 Nitrogenase Fixes Nitrogen
Product: Ammonia (NH3)
Nitrogenase
(Page 789)
Root hair
l:
� Rh;Wb;'
.�
..�::
Root hairs release chemical signals that attract Rhizobium.
Rhizobium proliferates and
,----::;: u o co
10
10
o
Colder
20
30
.... I------------�
40
o
Warmer
10
20
30
Colder
Warmer
Environmental temperature (0G)
Environmental temperature (0G)
40.9 Ectotherms and Endotherms React Differently to Environmental Temperatures
(Page 862)
(8) Loxodonta africana
(A) A lizard basks in the sun when air temperature is cold.
During the day the lizard shuttles between sun and shade, spending more time in shade as air temperature rises.
The lizard returns to the constant temperature of its burrow at night.
40 6
L
�
30
::J
]l
(l) Q.
E
40
20
� 10
Temperature of burrow 6am
Sunrise
8am
10am
Noon
2 pm
4 pm
6 pm
8 pm
t
Sunset
40.10 Ectotherms and Endotherms Use Behavior to Regulate Body Temperature
(Page 863)
PHYSIOLOGY, HOMEOSTASIS, AND TEMPERATURE REGULATION
Evaporation of water from
Objects exchange
body surfaces or breathing
radiation with each
passages cools the body.
Solar radiation
other and with the sky. Warmer objects lose heat to cooler objects.
Heat is lost by
convection when a stream of air (wind) is cooler than body surface temperature.
objects of different temperatures come into contact.
40.11 Animals Exchange Heat with the Environment
(Page 863)
IN OCEAN
30
100 90 80 The iguana's heart rate
70
drops rapidly when it
60
is cooling.
10
50 40
I
Heart rate
30 20 10
o L------L------�------L-----�------� o 10 20 40 30 50
L_�
______
60
Time (min) 40.12 Some Ectotherms Regulate Blood Flow to the Skin
(Page 864)
0
I (1) OJ ;::+
i& (1) 0' (1)
� Ul
"0
� 3 s·
c
CD
I
427
428
(HAPHR 40
(B)
(A) "Cold" fish
"Hot" fish
In the gills, blood is
Cold blood flows through
In the gills, blood is
oxygenated and cooled to
the center of the fish in
oxygenated and cooled to
gills to the body in arteries
seawater temperature.
the large dorsal aorta.
seawater temperature.
just under the skin.
Cold blood flows from the
The heart pumps blood to the gills.
heat exchanger, arterial blood flowing into the muscles is warmed by venous blood flowing
\countercurrent heat exchanger 40.13 "Cold" and "Hot" Fish
out of the muscles.
(Page 865)
I
20 Within the thermoneutral zone, body temperature is regulated by altering heat loss through the skin.
Metabolic rate ./" Basal metabolic r ���
8 7 .,
Shrew
'\
____
.r:
.,
OJ � N
0
�
.� (5
.0 4,000,000 new cases/yr
Symptoms similar to gonorrhea, although often there are no obvious symptoms. Can lead to pelvic inflammatory disease in females
Genital herpes
500,000 new cases/yr
Small blisters that can cause itching or burning sensations are accompanied by inflammation and by secondary infections
Genital warts
10% of adults infected
Small growths on genital tissues. Increases risk of cervical cancer in women
Hepatitis B
5-20% of population
Fatigue, fever, nausea, loss of appetite, jaundice, abdominal pain, muscle and joint pain. Can lead to destruction of liver or liver cancer
HIV/AIDS
Approximately 900,000 casesa
Failure of the immune system (see Section 18.6)
"HIV / AIDS is widespread in other parts of the world, most notably in the southern part of the African continent. The infection is spreading rapidly in Southeast Asia and India. Estimated number of people infected with HIV worldwide in 2006 was 40 million.
(Page 917)
(HAPTfR
Animal Development: from Genes to Organisms The cortical cytoplasm rotates relative to the inner cytoplasm.
Animal cortical cytoplasm (pigmented)
Animal pole (A)
"'----Vegetal poleM
43.1 The Gray Crescent
Vegetal cortical cytoplasm (unpigmented)
(Page 922)
------- ----- - - - ---
457
(HAPUR 43
458
(A) Fertilization
�-Catenin (orange) is distributed throughout cytoplasm. '--':0-
0
0
K+ channel o
°0 0 .
Open o
Ii)
0
0
0
0
Na+'---
o
0 0
Closed @)
0
@l
Inside of cell 5' E
� m
:::co
0
0
0 Ii)
0
0
0 0
0
(j)
0
0
0
0
0
n
o
o
, 0
0
00
0
0
+
0
Open
Open
/ K+
0
I
o
o
0
0
o
0
Closed
0
!
0
0
0
0
o
o
0
0
0
o
0 0
0
0
0 0
Closed o
0
0
0
o 0
0
Open o
0
0
...
+
o
0
0 0 o 0
0
0
-
Na+ channel open
& E -90
m L
0
0
0
�-60 D
0
Hyperpolarized Chemically gated K+ channel open
0
0
0 o
0
0
0
0
o
Closed 0
o
o
0
0
0 0
o o
o
Depolarized
I
/
R,"'og po"mt'"
r
..
o_
d
1/
44.9 Membranes Can Be Depolarized or Hyperpolarized
\
(Page 951)
Time
'(
1 7
"_polrui",
More K+ flowing out of \ the cell hyperpolarizes it.
0
0 0 0
Open o
More K+ channels open
I I
0
0
K+ channel open
�o
�
0
-
0
Voltage-gated Chemically gated K+ channel Na+ channel
0 0
0
Depolarized Voltage-gated Na+ channel open
0
CHAPHR 44
476
Inside axon
50
.jili,T!i!,fi'if·,,�!,·�!,!;;-,!!;-:; ,if.II:!i,0iii; +
+
+
+
+
+
Outside axon
+
+
+
The
+ + +
5' 30
E� Q) m
action potential is a sudden,
brief reversal of polarity of the membrane potential.
0
(5
n. Q) c
�
� -40 � -50
-60 1
Outside of cell K+
o
0
0
channel
0
o
o
0
0
0
0
I
o
Open
0
K
+
0
channels
create the resting potential.
�o / \ 0
Voltage-gated K + channel
0 0 0
o
:�
o
-7 0
o
0
0
0 0 0
0
0
0
0
0
0
0
0
0
u
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0 0
0
0
0
0 0 0
0
D 0
0
Time
0
0
0 0
-0 0
0 0
0
0
o
0 0
0
0
OJ
0
0
0
o
0
0
0
00
0 00 o
0
I:)
0
0 0 0
0
0
0
0 0
0
0
0
0
0
0
0
0
0
0
0
0
0 0
�
0
0
0
0
0
0
0 0 0 0 0
o
0
0
0
0
0
0
0
0
0
0
0
0
o 0
0
o Ao
10 0
0
Activation gates of some Na+
Additional voltage-gated Na+
channels open, depolarizing the
channel activation gates open,
close; gated K+ channels open,
cell to threshold.
causing a rapid spike of
repolarizing and even
depolarization-an action potential.
hyperpolarizing the cell.
All gated channels close. The cell retums to its resting potential. Na+ inactivation gates reopen.
44. 1 0 The Course of an Action Potential
0
0
0
0
�
(Page 952)
0(
,. Na+ channel inactivation gates
.----/
N E URONS AND NERVOUS SYSTEMS
+ + + + + ++
Time
+ + + + + + ++ + + + +
Outside axon
Outside axon
Point A
--- - -___
Point B
(B) Time 1
r-------�
Voltage-gated Na+ channels open in response to the electrical stimulus, generating an action potential. o
o
o
o
o
o
Point A
o
o
o
o
o
o
Point B
(C) Time 2 Upstream Na+ channels inactivate, making the membrane refractory.
, Voltage-gated K+ channels open, hyperpolarizing the axon, then close.
As it travels down the axon, the action potential stimulates more Na+ channels to open in a self-extending forward stream.
o
o
o
o
€) 0 0 o
Point A
0
44.11 Action Potentials Travel along Axons (Page 953)
o 000 0 0
o
o
Point B
Q
477
478
(HAPUR 44
Upstream Na+ channels inactivate, making the membrane refractory. Voltage-gated K+ channels open, repolarizing the axon.
44.12 Saltatory Action Potentials (Page 954)
NEURONS AND NERVOUS SYSTEMS
Presynaptic cell (motor neuron)
arrives at axon terminal.
Na+ channels open; depolarization causes voltage-gated Ca2+ channels to open.
Acetylcholine is broken down and the components are taken back up by the presynaptic cell. Acetylcholine and vesicles are recycled.
Acetylcholine molecules in veSicle
�
•
The spreading depolarization fires an action potential in the postsynaptic membrane.
Activated receptors open chemically gated cation (Na+, K+, Ca2+) channels and depolarize the postsynaptic membrane.
triggers fusion of acetylcholine vesicles with the presynaptic membrane.
Acetylcholine molecules diffuse across the synaptic cleft and bind to receptors on the postsynaptic membrane.
Postsynaptic cell (muscle cell)
44.13 Chemical Synaptic Transmission Begins with the Arrival of an Action Potential (Page 956)
479
480
CHAPHR 44
When ACh binds at specific sites on the receptor, the channel opens, allowing Na+ to enter the postsynaptic cell.
The acetylcholine receptor-mediated channel is normally closed. Outside of cell
o
Na+
cf o
ACh
------ ------ --- ---
Acetylcholinesterase breaks down ACh, causing the channel to close once again.
o
ACh /
0
receptor
o
Inside of cell
0 o
o
44.14 The Acetylcholine Receptor Is a Chemically Gated Channel (Page 957)
(A) :>
Em
+60
� (5
Ql
o
Spatial summation occurs when several excitatory postsynaptic potentials (EPSPs) arrive at the axon hillock simultaneously.
� -50 - � :;
Ql
�
Action potential
/
(8) Temporal summation
means that postsynaptic potentials created at the same synapse in rapid succession can be summed.
EPSPs Threshold
l
- -----
-601 + t ! ! ! /+ + /L
Resting potential
_
_
-
1
2
Synapse number
2
++
3
11
H
11
#+
1 11
Milliseconds ----..
44.15 The Postsynaptic Neuron Sums Information (Page 957)
N EURONS A N D NERVOUS SYSTEMS
Neuro transmitter
Outside of cell a a
lonsa
o a a a a a 0
a
The receptor activates a G protein, causing a GTP to replace the GOP on the a subunit.
a
a
A G protein subunit activates an ion channel directly, or indirectly through a second messenger.
Inside of cell 44.16 Metabotropic Receptors Act through G Proteins (Page 958)
481
482
CHAPUR 44
Some Well-Known Neurotransmitters NEUROTRANSMITIER
ACTIONS
COMMENTS
Acetylcholine
The neurotransmitter of vertebrate motor neurons and of some neural pathways in the brain
Broken down in the synapse by acetylcholinesterase; blockers of this enzyme are powerful poisons
Norepinephrine
Used in certain neural pathways in the brain. Also found in the peripheral nervous system, where it causes gut muscles to relax and the heart to beat faster
Related to epinephrine and acts at some of the same receptors
Dopamine
A neurotransmitter of the central nervous system
Involved in schizophrenia. Loss of dopamine neurons is the cause of Parkinson's disease
Histamine
A minor neurotransmitter in the brain
Involved in maintaining wakefulness
Serotonin
A neurotransmitter of the central nervous system that is involved in many systems, including pain control, sleep/wake control, and mood
Certain medications that elevate mood and counter anxiety act by inhibiting the reuptake of serotonin (so it remains active longer)
ATP
Co-released with many neurotransmitters
Large family of receptors may shape postsynaptic responses to classical neurotransmitters
Adenosine
Transported across cell membranes; not synaptically released
Not released synaptically; mainly has inhibitory effects on neighboring cells
The most common excitatory neurotransmitter in the central nervous system
Some people have reactions to the food additive mono sodium glutamate because it can affect the nervous system
Common inhibitory neurotransmitters
Drugs called benzodiazepines, used to reduce anxiety and produce sedation, mimic the actions of GABA
MONOAMINES
PURINES
AMINO ACIDS
Glutamate Glycine Gamma-aminobutyric acid (GABA) PEPTIDES
Endorphins Enkephalins Substance P
Modulation of pain pathways
Receptors are activated by narcotic drugs: opium, morphine, heroin, codeine
Used by certain sensory nerves, especially in pain pathways
Released by neurons sensitive to heat and pain
Widely distributed in the nervous system
Not a classic neurotransmitter, it diffuses across membranes rather than being released synaptically. A means whereby a postsynaptic cell can influence a presynaptic cell
GAS
Nitric oxide
(Page 959)
N E URONS AND N ERVOUS SYSTEMS
(A)
(8)
Strong depolarization of the cell2by Na+ influx, displaces Mg +, which was blocking the NMD A receptor ...
.. . which then is open to2both Na+ and Ca +. " Postsynaptic ./ cell
44.17 Two lonotropic Glutamate Receptors (Page 960)
Ca2+ acts as a second messenger, triggering long-term cellular change.
483
484
CHAPHR 44
HYPOTH ESIS: Repeated stimulation can change the properties of a synapse. METHOD
cell is stimulated through either of two input pathways and responses recorded.
A
Response to low level stimulation through electrode 1
Recording electrode
�� 7 J
Cla"d "II
Stimulating electrode 1
High-frequency stimulation is given through stimulating electrode 1 .
RESULTS
I ..:. . . - . . .. . . . ..a . . . -s •• I • •.•• · • • e.
..... _s i --; - i --; .. .!.-
••
s
a.
;
• •
.
. .
Stimulating electrode 2
o � c
f� :E3
� E
Q):;::; (J)Ul
.
. .
.sa .\. . .
• • as.
-.
I
T ime
The cell responds similarly to the same low level of stimulation from either electrode. The dots represent responses recorded 30 seconds apart. Response to low level stimulation through electrode 2
••••• as. - . .
When low-level stimulation resumes, the cell has a long-lasting increased sensitivity to that stimulation.
, The sensitivity of the cell to stimulation through electrode 2 remains unchanged, however.
• • • • ••• ••• • • • • • • • • • • • •••• •• • •• ••• •• • : •• • ••• : : :••• •,.....- ••• • • .• •-..••• - ---...... - -. -... _". ..... - .'- ;--.- -� - -.- - � - - -:--- .�-- -- - - - -. ..- �•..•----
.
.
L-_____�
Time
C O N CLU S I O N : High-frequency stimulation of synapses can cause a long-lasting change in the sensitivity of these synapses (long-term potentiation, or synaptic "memory") .
44.18 Repeated Stimulation Can Cause Long-Term Potentiation (Page 961)
Sensory Systems
(HAPHR
lonotropic sensory receptors
Metabotropic sensory receptors
A
r
, r�------�A�--�
Thermoreceptor
Mechanoreceptor
Pressure opens an ion channel. Outside of cell
Pressure
1
0 0 + + 0 0 0 + + ++ +
+ + ++
Pressure-sensitive cation channel Inside of cell
Temperature influences a membrane protein that is a cation channel or is closely associated with the channel. Warmth +
Temperature-sensitive cation channel
Electroreceptor
An electric charge opens an ion channel.
o
o
o
00
o
Chemoreceptor
A molecule binds to a receptor, initiating a signal that controls the ion channel via second messenger cascade.
Photoreceptor
Light alters a receptor protein, initiating a signaling cascade that controls an ion channel. cGMP-gated Na+ channel
Taste/smell molecule
+ + +0 + + 0 00+
Voltage-gated Na+ channel
o
.
/ G protein messenger
I
o
messenger
45.1 Sensory Cell Membrane Receptor Proteins Respond to Stimuli (Page 966)
� I
485
486
CHAPUR 45
Stretching a muscle is the stimulus...
. .. that activates the opening of ion channels in stretch receptor dendrites. Stretch_ receptor neuron
The resulting depolar ization spreads to the cell body, creating a receptor potential ...
Cell body
. . . which spreads to hillock, stimulating action
---..:::----.:::r the axon
potentials.
The action potentials travel down the axon.
Axon
45.2 Stimulating a Sensory Cell Produces a Receptor Potential (Page 966)
Olfactory bulb Olfactory
bulb
Nasal
Neurons in a glomerulus receive input only from receptor cells expressing the same receptor gene. Action potentials generated by odorant binding are transmitted to glomeruli in the olfactory bulb.
. .. .::. .
• • • •
Nasal cavity
�
.. •
•
... ...:.. .. .:. . . : . .. . . •
• •
Odorant
45.4 Olfactory Receptors Communicate Directly with the Brain (Page 969)
• •
-:�V Mucus film
•
•
•
•
molecules
•
•
Olfactory cilia have receptors that bind specific odorant molecules.
SENSORY SYSTEMS
Tastant molecules bind to receptors on the microvilli of sensory cells. Microvilli
Sensory celis release neurotransmitters that depolarize the dendrites of sensory neurons.
Sensory neuron --- Axon to central nervous system
45.5 Taste Buds Are Clusters of Sensory Cells (Page 970)
Free nerve endings
Pain, itch, temperature
corpuscle
Pressure
45.6 The Skin Feels Many Sensations (Page 971)
487
488
(HAPUR 45
(A) Muscle spindles
� Muscle
Muscle spindles are stretch receptors. When muscle spindles are stretched" . C e
_:J � g' � '
o Q)
itg a5(f)
""
"
. .•...
. . . • .Cw•..• •"'
! ! !I!!!"""",,,,"
. . . sensory neurons associated with them transmit action potentials to the eNS. These signals stimulate motor neurons that initiate muscle contraction.
Muscle
Golgi tendon organs sense load and measure the force of muscle contraction. When contraction becomes too forceful . . . C
g
oQ) OlC .S;: C .::: 0 LL (f) C Q) (f)
Load on muscle
/
Sensory neuron
45.7 Stretch Receptors (Page 971)
motor neurons, and the muscle relaxes.
SENSORY SYSTEMS
Sound waves travel through the auditory canal and vibrate the tympanic membrane.
The ossicles transmit vibrations of the tympanic membrane to the oval window of the cochlea.
489
Vibrations at oval window create pressure waves in fluid-filled cochlear canals.
Semicircular canal
Cochlea
Pinna--
�_
ear
ear
__
45.8 Structures of the Human Ear (Page 972)
, Pressure waves flex
flexed, it bends stereocilia on hair cells in the Organ of Corti.
------
•
nerve The movements of stereocilia are transduced into action potentials in the auditory nerve.
490
CHAPHR 45
Hypothetical uncoiling of cochlea
Pressure waves travel far down the upper canal and flex the basilar membrane, activating action potentials in low-frequency sensors. Low pitch:
400
window canal
Hz
Medium pitch: Pressure waves travel only part of the way down the upper canal before flexing the basilar membrane and activating mid-frequency sensors.
3,000
Hz High pitch: Pressure waves travel a short distance before flexing the basilar membrane and activating high-frequency
22,000 Hz
45.9 Sensing Pressure Waves in the Inner Ear (Page 973)
SENSORY SYSTEMS
(A)
( 8)
The stereocilia project into the middle canal, which contains a fluid high in K+ and low in Na+. Thus, when K+ channels open, K+ enters and depolarizes the cell.
Membrane depolarization opens voltage-gated Ca2+ channels, causing neurotransmitter release. 45.10 Hair Cells Have Mechanosensors on Their Stereocilia (Page 974)
491
Filaments linking
�A stereocilia I . . .and close opposite direction.
'" Sensory neurons,/
492
UIAPUR 4S
In a semicircular canal
Direction of body movement Otoliths ("ear stones") are granules of calcium carbonate on the top surface of a gelatinous substance (the otholith membrane).
In the vestibule
Hair cell
Dendrites of sensory neurons
45.11 Organs of Equilibrium (Page 975)
Support cell
Force of gravity
Direction of body movement
•
Due to inertial mass of otholiths, when head changes position, accelerates, or decelerates, the gelatinous otholithic membrane bends hair cells.
SENSORY SYSTEMS
493
A lateral line canal lies just below the skin surface. Direction of water flow Structures called cupulae project into the canal. As the fish moves through the water, fluid in the canal pushes against the cupulae.
organ
Lateral line nerve
Water flow Cupula---� --., Stereocilia
/
/
Hair cells -f==ttil�1I Dendrite -[--
Stereocilia on hair cells in the cupula bend, creating a signal that causes depolarization of the dendrites of associated neurons.
\\
____
45.12 The Lateral Line Acoustic System Contains Mechanosensors (Page 975)
Plasma ll-cis-retinal covalently bound to protein When all-trans-retinal returns to II-cis conformation, it is photoresponsive again. ll-cis-retinal is sensitive to Iight. . .
Activated transducin
c
.� a / 'Y
Transducin (G protein)
@
GW
ll-cis-retinal
...and when i t absorbs a photon it becomes all-trans-retinal. After passing through unstable intermediates, all-trans-retinal activates a G protein cascade that results in a change in membrane potential.
45.13 Light Changes the Conformation of Rhodopsin (Page 976)
494
CHAPHR 45
HYPOTHESIS: Rod cells respond to light (Le., absorption of photons) by changes in their membrane potentials.
RESULTS
METHOD
Record membrane potential from inner segment of rod cell and associated bipolar cell. Stimulate rod cell with flash of light.
Outer segment
I
When rod cell outer segment is exposed to light, the inner segment hyperpolarizes.
>
.s -35 ,...-.'-
co
� OJ
o
0..
-45
OJ () OJ [[
-55
o 0.
Inner segment potential controls the amount of neurotransmitter released.
Synaptic { terminal
light
����
C O N CLUS I O N : The membrane potential of rod cells is depolarized in dark and hyperpolarized by light.
45.14 A Rod Cell Responds to Light (Page 977)
-
-- -- ------
------ ------ -----
------- ------- ----- ----
------ ----
--- ------
SENSORY SYSTEMS
Outside of rod cell
Na+ 0
Rod cell outer \ membrane !
I:
I
!!
Na+000 0 00 0
Na+000 0 00 0 o 00
�
cGM P-mediated Na+ channel 0 / in open position
oo o
I
o 00
.1
Cytoplasm of rod cell
II
I'
Activated PD E hydrolyzes cGMP to 5'-GMP, causing Na+ channels to close.
/" Phosphodiesterase
(PDE)
. ..causing a G protein, transducin, to exchange GTP for GDP. 45.15 Light Absorption Closes Sodium Channels (Page 978)
)
(B)
(A) The compound eyes of a fruit fly each contain hundreds of ommatidia.
_:�._:c"'r:o--=-_ Corneal lens Crystalline cone Pigment cell
(retinula cell)
Bundle of axons to brain ?----- Basement membrane 45.16 Ommatidia: The Functional Units of Insect Eyes (Page 978)
Ommatidium
,
I'
495
(HAPHR 45
496
(A) Human
Ciliary muscle (8) Octopus
Suspensory ligaments
Retina
Iris
Cornea Cornea
Iris
� Central artery (red) and vein (blue) Vitreous humor 45.17 Eyes Like Cameras (Page 979)
A camera's lens focuses an inverted image on the film in the same way the eye's lens focuses an image on the retina.
-I
For near vision, ciliary muscles contract, causing the lens to round up.
For distant vision, ciliary muscles relax and suspensory ligaments pull the lens into a flatter shape. 45.18 Staying in Focus (Page 979)
U�
�L-
�----
W
Optic nerve
Double layer of � receptor cells
�
__
The eye of the octopus is very similar in structure to the vertebrate eye, but it evolved independently.
SENSORY SYSTEMS
Q) u c Cll .0
o
(f) .0 Cll Q) >
�
X
....... Metabolism of resting fish
0
0
10
20 30 Water temperature (0C)
40
48.2 The Double Bind of Water Breathers (Page 1027)
523
524
(HAPUR 48
Internal gills
(A) External gills
(8)
(C) Lungs
(0) Tracheae
� � 48.3 Gas Exchange Systems (Page 1028)
(A)
Air sacs
Trachaea (C)
Spiracles
48.4 The Tracheal Gas Exchange System of Insects (Page 1029)
GAS EXCHANGE IN ANIMALS
Water enters when moot" " opoo.
�;:;� Ifi/
J;.1f:\
� � l
GIIlSllt opocoo,ocflap
(8)
./Mouth
iA h
Gill fl l
� r;
525
�
�
Horizontal section through head
,�
Watocftow
Water with high 02 ventilates gills.
Deoxygenated blood
I
Afferent blood vessel
48.5 Fish Gills (Page 1029)
02 diffuses from water into the blood over the entire length of a lamella.
Blood perfusion of the lamellae is countercurrent to the flow of water over the lamellae.
526
(HAPHR 48
(A) Concurrent flow
Gill lamella
% Saturation
Water flow 1 00% 80 70 (8) Countercurrent flow
% Saturation
Water flow In the countercurrent exchanger, a gradient of 0 2 saturation exists over the full length of exchange surfaces. 48.6 Countercurrent Exchange Is More Efficient (Page 1030)
(A) Avian air sacs and lungs
Lung
(8) Microscopic view of avian lung tissue
Air capillaries carry air from a parabronchus over blood capillaries, where 0 2 is absorbed, and then out through the parabronchus.
Air capillaries 48.7 The Respiratory System of a Bird (Page 1031)
GAS EXCHANGE IN AN IMALS
{XP{RI M {NT HYPOTHESIS: Air flow in birds' lungs is tidal, with air sacs and lungs filling and emptying with each breath. METHOD
Place oxygen sensors at different locations in a bird's respiratory system. Give the bird one breath of pure O2 , followed by a breath of normal air. Record when oxygen pulse reaches different sensors. RESULTS
Breath 1
The breath marked by pure 0 2 is inhaled directly into the posterior air sacs. Bronchus
Anterior air sacs Inhalation
Lung
�[1
,------'
��/ 0 � Postenor air sacs �� -----.J
7
Trachea
During exhalation, the marked breath flows into the lungs. ..
� . 0 �G �
Anterior air sacs Exhalation
Parabronchus
� �
-....
Postenor lr sacs
�
During the next inhalation, the marked breath flows from the lungs to the anterior air sacs. Lung
-+-
Inhalation
� [1 �
0�
-+-
Anterior air sacs
�
. Postenor air sacs
Anterior air sacs
, Finally, during the next exhalation, the breath marked by pure 0 2 is expelled. C O N CLUS I O N : The hypothesis is not supported. Instead, air travels through the lungs in one direction, from the posterior to the anterior air sacs. Two cycles of inhalation and exhalation are,required.
48.8 The Path of Air Flow through Bird Lungs (Page 1031)
527
528
(HAPUR 48
The person breathes through the mouthpiece . . .
R{S{ARCH M{TH O D Inspiratory reserve volume is an additional capacity of the lungs that enables the deepest breath .
.. . and the computer records the air that
j
6
t
5
Vital cap acity
��
L__
spirometer
normal amount of air exchanged in breathing when at rest.
L-��
__ __ __
Expiratory reserve
volume is the additional air that can be forcefully exhaled.
T�I lung cap acity
4 3
Liters
2
�--L O
__ __ __ __ __ __
Residual volume is the amount of air left in the lungs after maximum exhalation. f,-----..I
48.9 Measuring Lung Ventilation (Page 1032)
------- ----- ----- -----
--
---------
GAS EXCHANGE IN ANIMALS
. � �
(A)
The lungs lie within the thoracic cavity, which is bounded by the ribs and the diaphragm.
N ,,,, """'9' oral cavlty
� �::::' r:P ,c::7
529
� Pleural membranes line the thoracic cavity and also cover the lungs. -
The bronchi are the major air passageways of the lungs. They lead to the bronchioles, which are finely branched, as are the blood vessels.
Air enters the lungs from the oral cavity or nasal passages via the trachea and bronchi . . . (8)
Oxygenated blood to heart _____ Pulmonary venule Smooth muscle __u,_..,-_
Red blood cells
Deoxygenated blood from hea rt
Pu lmon ary arteri ol e
Alveoli
(C)
In the alveolus, the air is very close to the blood flowing through the networks of capillaries surrounding the alveoli. Alveolar walls and capillary walls are extremely thin, minimizing the distance that 02 must diffuse to about 2 �m.
Smallest blood vessels (capillaries)
48.10 The Human Respiratory System (Page 1033)
Deoxygenated blood from heart
530
(HAPHR 48
Q)
_
oS � til (j) � � OJ tl
I o E ·§j
£� 2! (!l
E
gj co ::>
rt .9
+2 +1 0 -1 -2 -3 -4
Exhalation
Inhalation
Pleural cavity pressure
�---
-5
-6
-7 -8 L-________________�_________________
f
Thoracic cavity expands during inhalation
/�
During inhalation: Diaphragm contracts Thoracic cavity expands Intrapleural pressure becomes more negative Lungs expand Air rushes in
• •
• • •
During exhalation: Diaphragm relaxes Thoracic cavity contracts Intrapleural pressure becomes less negative Lungs contract Gases in lungs are expelled • • •
• •
f:
500 400 OJ c 300 til .c 0 200 x Q) 1 00 1J 0 .0 1J
4
e!0 2
U5
3 4 5 Weeks of starvation Carbohydrate reserves are depleted by only a single day without food intake.
When body fat has been exhausted, protein is lost at an accelerating rate, with serious consequences.
50.3 The Course of Starvation (Page 1071)
Animals use acetyl groups obtained from their food to build more complex organic molecules. The acetyl group is present in virtually all of the foods animals ingest. Protein, carbohydrate, or fat metabolism
----J .. �
Steroid hormones H2C - COOH
H 0 I II H C -C I
H
Oxaloacetate
Acetyl group carbon skeleton
Amino acids, I .. � heme, and HO - C- COOH ;-----)l I other compounds H C - C GlOH Citrate
Palmitic acid (and other fatty acids)
50.4 The Acetyl Group Is an Acquired Carbon Skeleton (Page 1072)
N UTRITIO N , D I G ESTION, AND ABSORPTION
549
Eight essential amino acids for humans Tryptophan Methionine Valine Grains (corn in tortilla chips)
Threonine Phenylalanine Leucine Isoleucine Lysine
Legumes (beans in bean dip)
50.5 A Strategy for Vegetarians (Page 1072)
Mineral Elements Required by Animals ELEMENT
SOURCE IN HUMAN DIET
MAJOR FUNCTIONS
Calcium (Ca)
Dairy foods, eggs, green leafy vegetables, whole grains, legumes, nuts, meat
Found in bones and teeth; blood clotting; nerve and muscle action; enzyme activation
Chlorine (CI)
Table salt (NaCI), meat, eggs, vegetables, dairy foods
Water balance; digestion (as HCI); principal negative ion in extracellular fluid
Magnesium (Mg)
Green vegetables, meat, whole grains, nuts, milk, legumes
Required by many enzymes; found in bones and teeth
Phosphorus (P)
Dairy, eggs, meat, whole grains, legumes, nuts
Found in nucleic acids, ATP, and phospholipids;bone formation; buffers; metabolism of sugars
Meat, whole grains, fruits, vegetables
Nerve and muscle action; protein synthesis; principal positive ion in cells
Sodium (Na)
Table salt, dairy foods, meat, eggs
Nerve and muscle action; water balance; principal positive ion in extracellular fluid
Sulfur (S)
Meat, eggs, dairy foods, nuts, legumes
Found in proteins and coenzymes; detoxification of harmful substances
Chromium (Cr)
Meat, dairy, whole grains, legumes, yeast
Glucose metabolism
Cobalt (Co)
Meat, tap water
Found in vitamin B1 2; formation of red blood cells
Copper (Cu)
Liver, meat, fish, shellfish, legumes, whole grains, nuts
Found in active site of many redox enzymes and electron carriers; production of hemoglobin; bone formation
Fluorine (F)
Most water supplies
Found in teeth; helps prevent decay
Iodine (I)
Fish, shellfish, iodized salt
Found in thyroid hormones
Iron (Fe)
Liver, meat, green vegetables, eggs, whole grains, legumes, nuts
Found in active sites of many redox enzymes and electron carriers, hemoglobin, and myoglobin
Manganese (Mn)
Organ meats, whole grains, legumes, nuts, tea, coffee
Activates many enzymes
Molybdenum (Mo)
Organ meats, dairy, whole grains, green vegetables, legumes
Found in some enzymes
Selenium (Se)
Meat, seafood, whole grains, eggs, milk, garlic
Fat metabolism
Zinc (Zn)
Liver, fish, shellfish, and many other foods
Found in some enzymes and some transcription factors; insulin physiology
MACRONUTRIENTS
Potassium
(K)
MICRONUTRIENTS
(Page 1073)
UIAPUR 5 0
550
Vitamins in the Human Diet VITAMIN
SOURCE
FUNCTION
DEFICIENCY SYMPTOMS
WATER-SOLUBLE
B1 (thiamin)
Liver, legumes, whole grains,
Coenzyme in cellular respiration
Beriberi, loss of appetite, fatigue
B2 (riboflavin)
Dairy, meat, eggs, green leafy vegetables
Coenzyme in FAD
Lesions in corners of mouth, eye irritation, skin disorders
Niacin
Meat, fowl, liver, yeast
Coenzyme in NAD and NADP
Pellagra, skin disorders, diarrhea, mental disorders
B6 (pyridoxine)
Liver, whole grains, dairy foods
Coenzyme in amino acid metabolism
Anemia, slow growth, skin problems, convulsions
Pantothenic acid
Liver, eggs, yeast
Found in acetyl CoA
Adrenal problems, reproductive problems
Biotin
Liver, yeast, bacteria in gut
Found in coenzymes
Skin problems, loss of hair
B12 (cobalamin)
Liver, meat, dairy foods, eggs
Formation of nucleic acids, proteins, and red blood cells
Pernicious anemia
Folic acid
Vegetables, eggs, liver, whole grains
Coenzyme in formation of heme and nucleotides
Anemia
C (ascorbic acid)
Citrus fruits, tomatoes, potatoes
Formation of connective tissues; antioxidant
Scurvy, slow healing, poor bone growth
A (retinol)
Fruits, vegetables, liver, dairy
Found in visual pigments
Night blindness
FAT-SOLUBLE
D (cholecalciferol)
Fortified milk, fish oils, sunshine
Absorption of calcium and phosphate
Rickets
E (tocopherol)
Meat, dairy foods, whole grains
Muscle maintenance, antioxidant
Anemia
K (menadione)
Intestinal bacteria, liver
Blood clotting
Blood-clotting problems
(Page 1074)
(B) A hard material called enamel, composed principally of calcium phosphate, covers the tooth.
(A)
Omnivores have
a mUltipurpose set of teeth.
Crown
Both the crown and the root contain a layer of bony material called dentine. . .
Gums Root
. . . within which is a pulp cavity containing blood vessels, nerves, and the cells that produce the dentine.
..
Carnivores have greatly enlarged canine teeth I� " ippiog, killiog, Md tearing their prey.
50.7 Mammalian Teeth (Page 1076)
Periodontal membrane
Carnivore cat) �
o Canines (used for ripping
and tearing)
Cement Bone Nerves and blood vessels (holds tooth in bone)
J;J
o Incisors (for cutting) III Premolars (for shearing) D
Molars (for grinding)
-'
.' I '
Herbivores use their incisors and canines, which are found far forward on the lower jaw only, to tear leaves off of plants. Their large molars and premolars then grind the plant matter.
N UTRITIO N , DIGESTION, AND ABSORPTION
Earthworm
..."
intestine 50.8 Compartments for Digestion and Absorption (Page 1077)
551
552
CHAPTn 5 0
(A) Earthworm
Earthworms have a longitudinal infolding of the intestinal wall, the typhlosole.
(8) Shark
Sharks have evolved a spiral valve that increases the
(e) Human
In most vertebrates, an enormous absorptive surface is achieved by the sheer length of the tubular small intestine . . .
. . . and the folding of its lining.
vessels
Capillaries
50.9 Greater Intestinal Surface Area Means More Nutrient Absorption (Page 1078)
N UTRITION, DIGESTION, AND ABSORPTION
Parotid salivary gland
Tongue
Sublingual and II"'r.--==� salivary glands Esophagus ----::;;;;iil�jj
Liver
Diaphragm
Gallbladder
}
DUOdenUm
_.-=;;-- Rectum ----"'�-A nus
50. 1 0 The Human Digestive System (Page 1079)
The submucosa contains a neural network.
Nerve net between muscle layers
Peritoneum The peritoneal membrane is continuous with the lining of the abdominal cavity. 50.1 1 T issue Layers of the Vertebrate Gut (Page 1079)
Small Intestine
553
554
(HAPTfR 50
(8) Peristalsis
(A) Swa ll ow i ng
Trachea (windpipe) Esophagus IiI Food is chewed and the tongue pushes the bolus of food to the back of the mouth. Sensory nerves initiate the swallowing reflex.
II The soft palate is pulled up as the vocal cords are pulled together to close the larynx.
50. 1 2 Swallowing and Peristalsis (Page 1080)
I!I The larynx is pulled up and
forward and is covered by the epiglottis. The esophageal sphincter relaxes. The bolus of food enters the esophagus.
II Peristaltic contractions propel the food to the stomach.
555
N UTRITION, DIGESTION, AND ABSORPTION
(A) Lower esophageal sphincter
Stomach
(B) Low pH converts pepsinogen to pepsin. In a process called autocatalysis, newly formed pepsin activates other pepsinogen molecules.
Mucus secreting cells
.Inogen � pepsll:1,
�
...--¥-tfd
Chief (enzyme secreting) cell
Gastric pit
(C)
50 . 1 3 Action in the Stomach
Bicarbonate is actively transported out of the blood side of the cell in
H+ is actively transported into the lumen of the
(Page 1081)
, K+ and CI leak out of the cell.
Carbonic anhydrase catalyzes formation of carbonic acid, which dissociates into H+ and HC03-·
556
CHAPHR SO
Marshall and Warren set out to satisfy Koch's postulates:
'00'1
The microorganism must be present in every case of the disease.
Results: Biopsies from the stomachs of many patients revealed that the bacterium was always present if the stomach was inflamed or ulcerated.
'mt, The microorganism must be cultured from a sick host. Results: The bacterium was isolated from biopsy material and eventually grown in culture media in the laboratory.
'00"
Helicobacter pylori
The isolated and cultured bacteria must be able to induce the disease.
Marshall was examined and found to be free of bacteria and inflammation in his stomach. After drinking a pure culture of the bacterium, he developed stomach inflammation (gastritis). Results:
'00"
The bacteria must be recoverable from the infected volunteers.
Biopsy of Marshall's stomach 2 weeks after he ingested the bacteria revealed the presence of the bacterium, now christened Helicobacter pylori, in the inflamed tissue. Results:
Antibiotic treatment eliminated the bacteria and the inflammation in Marshall. The experiment was repeated on healthy volunteers, and many patients with gastric ulcers were cured with antibiotics.Thus Marshall and Warren demonstrated that the stomach inflammation leading to ulcers is caused by H. pylori infections in the stomach.
50 . 1 4 Satisfying Koch's Postulates
(Page 1082)
The gallbladder stores bile, which aids in digesting lipids. Pancreatic duct intestine
The pancreas produces digestive enzymes and bicarbonate solution.
50 . 1 5 Ducts of the Gallbladder and Pancreas
(Page 1083)
NUTRITION, DIGESTION, AND ABSORPTION
(A) Digestion of fats
Dietary fats are emulsified into tiny droplets called micelles through the action of bile salts in the intestinal lumen.
557
Large lipid droplet Bile salts
MicelleS
�{)l-,Jo
k· ¢
Pancreatic lipase hydrolyzes fats in the micelles to produce fatty acids and monoglycerides.
......
..... J"
Monoglycerides
-.-/ �t 5J � d" 30° S
Hot deserts
esterlies
Forests
----
52.2 The Circulation of Earth's Atmosphere
Southeast trades
� C'i-..
)
)t'
(Page 1 1 15)
On the windward side of the mountain, air rises and cools, releasing moisture in the form of rain or snow.
On the leeward side of the mountain, air descends, warms, and picks up moisture, which results in little rain.
52.3 A Rain Shadow
(Page 1 1 15)
573
(HAPTlR 5l
574
)
Q
;'.� .� .
���i� . � g;J
�rth Equatorial Current -
.....
..--::=.- --: --
Equatorial Countercurrent
-+-
---- --.:
-
If
-� �
.
ySouth Equatorial Current t J
A � /.
BraZil (Current '---"
Falkland Current West Wind Drift 52.4 Global Oceanic Circulation
-------�
Benguela Current :;( � Agulhas -_ .../ Current �
West Wind Drift
(Page 1 1 1 6)
------ -------
575
ECOLOGY AND THE DISTRIBUTION OF LIFE
�-
- 300N
� ....
��(;>'
\�
"
- Equator
J
�.
�
- 30°8----1
rft _ Tropical evergreen forest _ Tropical deciduous forest c=J Thorn forest c=J Tropical savanna c=J Hot desert
I·.•.;1\1 Temperate deciduous forest
_ Chaparral c:::J Cold desert _ High mountains
(boreal forest and tundra)
_ Temperate evergreen forest
52.5 Biomes Have Distinct Geographic Distributions
(Page 1 1 1 7)
c:J Boreal forest c=J Arctic tundra c::::J Temperate grassland c=J Polar ice cap
CHAPUR 52
576
TUNDRA
20°C is a
"comfortable"
68°F.
O°C is the
freezing
of water
point
(=32°F).
5 cm equals
just over 2 inches.
Biological activity
Photosynthesis
�
Flowering Fruiting
�
Arctic tundra, Greenland
�
Mammals Birds Insects
�
41"r;�;Ji;��
Soil biota Jan
Jul
Dec
Community composition
Dominant plants
Perennial herbs and small shrubs Species richness Plants: Low; higher in tropical alpine Animals: Low; many birds migrate in
summer; a few species of insects abundant in summer
for
"'1'iiMd
Few species
Figure 52A
(Page 1 1 18)
Tropical alpine tundra, Teleki Valley, Mt. Kenya, Kenya
ECOLOGY AND THE DISTRIBUTION OF LIFE
BOREAL FOREST and TEMPERATE EVERGREEN FOREST
°C
15 10 5
0
-5
-10
-15
-20
-25
-30
Jan
Jul
Dec
Biological activity
Photosynthesis Flowering
Northern boreal forest, Gunnison National Forest, Colorado
Fruiting Mammals Birds Insects Soil biota Jan
Jul
Dec
Community composition
Ill'!11m€,.i1i11ffl"j
Trees, shrubs, and perennial herbs Species richness
Plants: Low in trees, higher in understory Animals: Low, but with summer peaks in
migratory birds
f.1'1liffi'"
Very rich in deep litter layer
Figure 528
(Page 1 1 19)
Southern boreal forest, Fiordland National Park, New Zealand
577
578
(HAPUR 52
TEMPERATE DECIDUOUS FOREST
...in winter
A Rhode Island forest in summer and ... Biological activity
Community composition Dominant plants
Trees and shrubs Species richness
Many tree species in southeastem U.S. and eastern Asia, rich shrub layer Animals: Rich; many migrant birds, richest amphibian communities on Earth, rich summer insect fauna Plants:
W.ibl1iiMd Rich
Figure 52C (Page 1 120)
ECOLOGY AND THE DISTRI BUTION OF LIFE
TEMPERATE GRASSLANDS
30 25 20 15 10 5 o -5 �-=�����-z����
Jan
cm
10
5
Jul
Dec
� �' '=i i __�� Precipitation
Biological activity
Nebraska prairie in spring
Flowering Fruiting Mammals Birds Insects Soil biota Jul
Jan
Dec
Community composition Dominant plants
Perennial grasses and forbs Species richness Plants: Fairly high Animals: Relatively few birds
because of simple structure; mammals fairly rich
.-ibl1iMld Rich
Figure 520
The Veldt, Natal, South Africa (Page 1 12 1)
579
(HAPHR 52
580
COLD DESERT
Temperature
_10 Ll--�����--��Dec Jul Jan Precipitation
]
•••
Jan
i';ijml�1 .I
I
.
Jul
Dec
Biological activity
Photosynthesis /"
---
Flowering
"'---
Fruiting
Sagebrush steppe near Mono Lake, California
�
�
Mammals Birds
�
Insects Soil biota Dec
Jul
Jan
Community composition Dominant plants
Low-growing shrubs and herbaceous plants Species richness Plants: Few species Animals: Rich in seed-eating birds,
and rodents; low in all other taxa
ants,
f.1"liffiid
Poor in species
Figure 52E
(Page 1 122)
Patagonia, Argentina
ECOLOGY AND THE DISTRIBUTION OF LIFE
HOT DESERT
Simpson Desert, Australia, following rain
Anza Borrego Desert, California Temperature
°C r-;c---;-;-----,---;o:--:---;:--.",---,;;--,
Community composition
Biological activity
Dominant plants
Many different growth forms Species richness Plants: Moderately rich; many annuals Animals: Very rich in rodents; richest bee
Jul cm
communities on Earth; very rich in reptiles and butterflies
Dec
�ii"1iffi"1
Precipitation
Poor in species
Annual total: 1!> cm
5 o
Jul
Jan
Figure 52F
(Page 1 123)
Dec
Jan
Jul
Dec
581
582
(HAPUR S2
CHAPARRAL
Santa Barbara County, California Biological activity
Temperature
°C 25
Flowering 15 10 "-----... 5
Community composition
O ��------L-��
Fruiting
Dominant plants
Mammals
Low-growing shrubs and herbaceous plants Species richness
Birds
Jul Figure 52G
(Page 1 124)
.1
Dec
Extremely high in South Africa and Australia Animals: Rich in rodents and reptiles; very rich in insects, especially bees Plants:
"'IIiffi1d
Moderately rich
Jan
Jul
ECOLOGY AND THE DISTRIBUTION OF LIFE
THORN FOREST and TROPICAL SAVANNA
35 30 25 20L-------�L-L-G
Jan Precipitation
cm ,.-,,========---:---o=---__ ---, -,,-� -Annual total: 74 cm
20 15 5
O L-------���--�����
Jan
Jul
Biological activity
Photosynthesis Flowering Fruiting
Thorn forest in Madagascar
Mammals Birds Insects Soil biota Jan
Jul
Dec
Community composition
'-:oj"n.e,,\AFffljN
Shrubs and small trees; grasses Species richness Plants: Moderate in
savanna
thom forest; low in
Rich mammal faunas; moder ately rich in birds, reptiles, and insects
Animals:
�ib1Ii1ti1n Rich
Figure 52H (Page 1225)
KwaZulu-Natal, South Africa
583
(HAPHR 52
584
TROPICAL DECIDUOUS FOREST
Temperature
°C
30 25 20LL����������
Dec
Jul
Jan
Precipitation
cm �""''''�.--:l]nn
35 30 25 20 15 10 5
Biological activity
Photosynthesis
Palo Verde National Park, Costa Rica, in the rainy season."
ZiJIP
� Flowering Fruiting
-
Mammals Birds
',,/;
i
Insects Soil biota Jan
Jul
Dec
Community composition
••t.j"ii,€"ili1tM1A1
Deciduous trees
Species richness Plants: Moderately rich in tree species Animals: Rich mammal, bird, reptile, and
amphibian communities; rich in insects
Li§1lnmD
Rich, but poorly known
Figure 521
(Page 1 126)
...and in the dry season
ECOLOGY AND THE DISTRIBUTION OF LIFE
TROPICAL EVERGREEN FOREST
The exterior of lowland wet forest
...and its interior, Cocha Cashu, Peru
and
Community composition
Biological activity
,------1 The weather is warm
Photosynthesis
rainy all year.
Dominant plants
Trees and vines
Flowering Fruiting
Precipitation
cm ,------. 30
Annual total: 262 cm
25
Mammals Birds
20 15
:;tL .,c.'··
Species richness Plants: Extremely high Animals: Extremely high
in mammals, birds, amphibians, and arthropods
�'fi111i1ti1n
Very rich but poorly known
\
Insects
10
Biological activity is high year round.
Soil biota
5
O���--����-�JL�
Jul
Jan
Figure 52J
(Page 1 127)
Dec
Jan
Jul
Dec
585
586
CHAPHR Sl
c::::=J Current land surface _ Continental shelf exposed c::::=J Deep water (� 200 m below current sea level) Thailand
separates two distinct modern
and the islands to the west.
Australia and New Guinea. 52.7 The Malay Archipelago during the Most Recent Glacial Maximum
Border of Mexican Plateau 7 - and tropical lowlands-
ANTARCT IC
52.8 Major Biogeographic Regions
(Page 1 129)
(Page 1 129)
587
ECOLOGY AND THE DISTRIBUTION OF LIFE
Taxonomic phylogeny
przewalski's horse Onager African ass Mountain zebra Grevy's zebra Plains zebra Area phylogeny
Central Asia Origin in North America
Middle East and Central Asia North Africa
Horses speciated as they moved from Asia to Africa.
Mountain ze bra
Plains zebra
South West Africa East Africa
SpeCiation of zebras has taken place entirely in Africa.
Eastern and Southern Africa 3
3.9 52.10 Taxonomic Phylogeny to Area Phylogeny
(8)
(A)
Small island
Island near mainland
/
�
Small islands far from the mainland
(SSF) have
the fewest species. The number
of species
reaches an equilibrium
(S)
Large islands near
when the number of new
the mainland
( SLN)
have the largest
number of species.
rate JJ OJ
(j)
CD
ro lL
.� t: m � (/)
co .� ()
a'S:
(j) (j)
ro C lL'O
o
S Number of sp ecies
....�
--
52.11 The Theory of Island Biogeography
(Page 1 132)
o
0
2 Millions of years ago (mya)
(Page 1 13 1)
SSF SLFSSNS LN Number of
species
.... �
---
588
(HAPT{R 52
IM;J'.,.' Number of Species of Resident Land Birds on Krakatau NUMBER PERIOD
1908
OF SPECIES
3
4
3
7
4
7
33
1952-1984 1984-1996
17
29
1934-1951 1951
2 28
1921-1933 1933-1934
COLONIZATIONS
13
1908-1919 1919-1921
EXTINCTIONS
36
{XP{RIM{NT HYPOTHESIS: Defaunated islands will be rapidly
(Page 1133)
recolonized, eventually achieving about the same number of species that they had prior to defaunation. METHOD
Erect scaffolding and tent to enclose islets. Fumigate small islets with a chemical (methyl bromide) that kills arthropods but does not harm plants. Periodically monitor recolonizations and extinctions of arthropods on the islands.
RESULTS
Recolonization was rapid, turnover rates were high, and the rate of recolonization was slowest on the most remote island. CONCLUSION: An island can support a certain equilibrium number of species.
52. 1 2 Experimental Island Defaunation
(Page 1133)
ECOLOGY AND THE DISTRIBUTION OF LIFE
L. huttoni
Modern geography
-;�A L;=7
Pliocene geography
_
•
\
Future location of Cook Strait
NEW ZEALAND
52.14 A Vicariant Distribution Explained
c=J Pacific polar
_ Pacific westerly wind 1I< Slightly older moraine
Older moraine
1 00 Age of moraine (years)
55. 1 7 Primary Succession on a Glacial Moraine
(Page 1 198)
>I
250 56.2 Zones of Upwelling are Productive
(Page 1 207)
Cold water from ice melt sinks
0°
•
4° 4° 4° 4°
Spring
Tumovers occur in the spring and fall, allowing nutrients and oxygen to become evenly distributed in the water column.
4° 4° 4° 4°
Surface water cools rapidly and sinks
..
4° 4° 4°
�
� CD 3
u ro
§.
c
CD
-0
.Q
The thermocline is a zone of sudden temperature change several meters below the surface. 22° 1 8° 6° 4°
Summer
(Page 1207)
(j
4°
4°
4°
56.3 The Turnover Cycle in a Temperate Lake
4°
:;::: � � CD 3
u ro
§. c CD
-0
.Q
CHAPHR 56
622
Ultraviolet radiation ... "' ;; ;;: ::. :.: .: ::. : ..:: :
�
Q) .r:: 0. (/) o
1§ i'i5
Much ultraviolet radiation is absorbed by the ozone layer. Horizontal circulati on ,
Sun The greatest amount of energy is used in metabolism and is unavailable to organisms at the next trophic level. Most exchange between layers takes place in the tropics, where heating of air is most intense. 56.4 The Two Layers of Earth's Atmosphere
(Page 1208)
Metabolism
Process
CJ � CIt CJ 56.5 Energy Flow through an Ecosystem
Photosynthesis Digestion, assimilation, and growth Excretion and death Metabolism
(Page 1209)
623
ECOSYSTEMS AND G LOBAL ECOLOGY
65.0 7 4.5 3. 3.3
Ecosystem
Open ocean Continental shelf Extreme desert, rock, sand, ice Desert and semidesert Tropical evergreen forest Savanna Cultivated land Boreal forest Temperate grassland Woodland and shrubland Tundra Tropical deciduous forest Temperate deciduous forest Temperate evergreen forest Swamp and stream Lake and stream Estuary Algal beds and coral reefs Upwelling zones
Primary production in the open ocean is low, but there is a lot of ocean.
2.9 2.7
.2.4 1 .8
t .7
-
1
- 1 .I 1 ]
1
,I
]
0.1
o
I
- 1
.I
-
J I
/. Compared with its ===:J percentage of Earth's 1
�
'I
- I
--,.�
J
-
1
Algal beds and coral reefs are highly productive.
3
4
5
6
L (
l-
�-
(Page 1210)
-
t=J
70 0
(A) Percentage of Earth's surface area
56.6 Primary Production in Different Ecosystem Types
::J
1
,
.I
. _ " --
2
1
::=J - 1
surface, tropical evergreen forest has high production.
1 .5 Pd:J � PO.4 PO.0 4 0� 0..31 � 1 .6
/fJ Of P
-.- - I- -
5.2
I
1 1
,
1
--
I
1 I.
I
500 1 000 1 500 2000 2500
(8) Average net primary production (g/m 2/year)
o
5
10
15
20
25
(C) Percentage of Earth's net primary production
624
(HAPTfR 56
Low primary production characterizes the hot subtropical deserts (where moisture is limiting) .. =-----1 and high latitudes (where cool fL--------.,..,._ temperatures lower photosynthetic rates).
Areas of high primary production are in wet tropical and subtropical regions and the wetter parts of temperate I------t latitudes.
Tons of carbon fixed per hectare per year D Ice caps 0 D 0-2.5 D 2.5-6.0 D 8.0-1 0.0 D 1 0.0-30.0
[]
•
6.0-8.0 >30 . 0
56.7 Net Primary Production of Terrestrial Ecosystems
Evaporation (59)
(Page 121 1)
Precipitation (95) Transport over land (36)
Precipitation (283)
Evaporation (31 9)
1 Althou9h rocks contain large quantities of water, this "locked-in" water plays a very small role in the hydrol09ical cycle.
56.8 The Global Hydrological Cycle
(Page 1212)
625
ECOSYSTEMS AND GLOBAL ECOLOGY
(A)
(8) 500 450 c"J o
400
• •
1 91 5-24 (before dams) 1 9S5-94 (after dam construction)
Q) � � x
350 � -g .� 8 300 "D Q)
co m
>- (f)
250
Q) � 0l Q)
200
"D o.
� .E2 Q) ()
��
!:2.
1 50 1 00 50 0
56.9 Columbia River Flows Have Been Massively Altered
N
D
J
F
M A Month
M
J
(Page 1213)
Atmospheric CO2 is the immediate source of carbon for terrestrial organisms. Atmospheric CO2
(750)
Deforestation (1 -2)
Terrestrial organisms (60) (1 00) (50)
Fossil fuels (6.5) Oceans (1 00)
Oceans (90)
1
Shallow (SOO)
I
The two largest reservoirs of carbon are carbon containing minerals in rocks (including fossil fuels) and dissolved carbon in the oceans. 56. 1 0 The Global Carbon Cycle
(Page 1214)
J
A
S
(HAPHR 56
626
380 E
0.
g (f) c o
� C
Q) o c o o
360
Each year CO2 concentrations rise during the Northern Hemisphere winter, when metabolism exceeds photosynthesis.
r----;;;=, ;;; �-./
340
300 L1 960
CO2 concentrations then fall during the summer, when photosynthesis exceeds metabolism. ���2E�����
�______
__ __
1 97 0
Year
1 990
2000
56. 1 1 Atmospheric Carbon Dioxide Concentrations Are I ncreasing
(Page 1214)
8,000 E
� 6,000 o o
N
.g
4,000
E �
2,000
Q) .c 0. (f) o
Millions of years ago (mya) 56. 1 2 Higher Atmospheric CO2 Concentrations Correlate with Warmer Temperatures
�
__ __ __
1 980
(Page 1215)
2005
ECOSYSTEMS AND GLOBAL ECOLOGY
(A) Atlantic Ocean
(8) Indian Ocean
10 Northern 30 75 E :;; 1 25 a. 8 200 300 500 7 00 L -L I -0.2 0.0
(C) Pacific Ocean
�
__ __ __
•
-L______ �
__ __ __
0.2
10 Southern 30 75 E :;; 1 25 a. 8 200 300 500 7 00 1L � -0.2 0.0
..
0.4 -0.2
•
0.2
0.4 -0.2
0.0
0.2
0.4
0.2
0.4 -0.2
0.0
0.2
0.4
•
Southern • • • •
�
----
0.0
� ----
---
0.2
0.4 -0.2
0.0
Deviation from expected norm (0C)
Observations Range of predictions from global clirnate models 0.0 Expected norm 56.1 3 Oceans Are Warming- and Not Just at the Surface
(Page 1215)
627
(HAPHR 56
628
Atmospheric N2
(30)
(44)
(40)
56. 1 4 The Global Nitrogen Cycle
Industrial fixation
Biological fixation
Denitrification
t
(Page 1216)
Total human input Nitrogen fixation in agroecosystems Fossil fuels Fertilizer and industrial uses -cCIl (j)
200
i f 1 50
OJ
� � c 0
� X
4= C
(j) OJ
Range of terrestrial bacterial nitrogen fixation in nonagricultural ecosystems
1 00 50
g
Z
1 900
1 920
1 940
1 960
1 980
2000
Year 56. 1 5 Human Activities Have Increased N itrogen Fixation
(Page 121 7)
Denitrification
(40)
Fixation
(6)
ECOSYSTEMS AND GLOBAL ECOLOGY
Average pH of precipitation
o 5.3 . 5.0
0 4.6 0 >5.6 . 4.2
629
Because of prevailing winds, acid precipitation affects areas far from the pollution sources.
Gulf of Mexico 1 985
Anoxia-low oxygen levels-results when eutrophication occurs and algal populations increase dramatically. Their decompositon uses up all available oxygen. 56.1 6 A "Dead Zone" Near the Mouth of the Mississippi River
(Page 121 7)
1 998
(j) Q) 'li Q) Cl. (j) r. (j)
