Chapter 12

Содержание

1. Chapter 12
2. Overview: The Key Roles of Cell DivisionThe
3. Fig. 12-1
4. In unicellular organisms, division of one cell
5. Fig. 12-2100 µm200 µm20 µm(a) Reproduction(b) Growth and development(c) Tissue renewal
6. Fig. 12-2a100 µm(a) Reproduction
7. Fig. 12-2b200 µm(b) Growth and development
8. Fig. 12-2c20 µm(c) Tissue renewal
9. Concept 12.1: Cell division results in genetically
10. Cellular Organization of the Genetic MaterialAll the
11. Fig. 12-320 µm
12. Every eukaryotic species has a characteristic number
13. Distribution of Chromosomes During Eukaryotic Cell DivisionIn
14. Fig. 12-40.5 µmChromosomesChromosomeduplication(including DNAsynthesis)Chromo-some armCentromereSisterchromatidsDNA moleculesSeparation ofsister chromatidsCentromereSister chromatids
15. Eukaryotic cell division consists of:Mitosis, the division
16. Concept 12.2: The mitotic phase alternates with
17. Phases of the Cell CycleThe cell cycle
18. Interphase (about 90% of the cell cycle)
19. Fig. 12-5S(DNA synthesis)MITOTIC(M) PHASEMitosisCytokinesisG1G2INTERPHASE
20. Mitosis is conventionally divided into five phases:ProphasePrometaphaseMetaphaseAnaphaseTelophaseCytokinesis
21. Fig. 12-6G2 of InterphaseCentrosomes(with centriolepairs)Chromatin(duplicated)NucleolusNuclearenvelopePlasmamembraneEarly mitoticspindleAsterCentromereChromosome, consisting
22. ProphaseFig. 12-6aPrometaphaseG2 of Interphase
23. Fig. 12-6bPrometaphaseProphaseG2 of InterphaseNonkinetochoremicrotubulesFragmentsof nuclearenvelopeAsterCentromereEarly mitoticspindleChromatin(duplicated)Centrosomes(with centriolepairs)NucleolusNuclearenvelopePlasmamembraneChromosome, consistingof two sister chromatidsKinetochoreKinetochoremicrotubule
24. Fig. 12-6cMetaphaseAnaphaseTelophase and Cytokinesis
25. Fig. 12-6dMetaphaseAnaphaseTelophase and CytokinesisCleavagefurrowNucleolusformingMetaphaseplateCentrosome atone spindle poleSpindleDaughterchromosomesNuclearenvelopeforming
26. The Mitotic Spindle: A Closer LookThe mitotic
27. An aster (a radial array of short
28. During prometaphase, some spindle microtubules attach to
29. Fig. 12-7MicrotubulesChromosomesSisterchromatidsAsterMetaphaseplateCentrosomeKineto-choresKinetochoremicrotubulesOverlappingnonkinetochoremicrotubulesCentrosome1 µm0.5 µm
30. In anaphase, sister chromatids separate and move
31. Fig. 12-8EXPERIMENTKinetochoreRESULTSCONCLUSIONSpindlepoleMarkChromosomemovementKinetochoreMicrotubuleMotorproteinChromosomeTubulinsubunits
32. Fig. 12-8aKinetochoreSpindlepoleMarkEXPERIMENTRESULTS
33. Fig. 12-8bKinetochoreMicrotubuleTubulinSubunitsChromosomeChromosomemovementMotorproteinCONCLUSION
34. Nonkinetochore microtubules from opposite poles overlap and
35. Cytokinesis: A Closer LookIn animal cells, cytokinesis
36. Video: Sea Urchin (Time Lapse)Video: Animal MitosisCopyright
37. Fig. 12-9Cleavage furrow100 µmContractile ring ofmicrofilamentsDaughter cells(a)
38. Cleavage furrowFig. 12-9a100 µmDaughter cells(a) Cleavage of an animal cell (SEM)Contractile ring ofmicrofilaments
39. Fig. 12-9bDaughter cells(b) Cell plate formation in
40. Fig. 12-10ChromatincondensingMetaphaseAnaphaseTelophasePrometaphaseNucleusProphase12354NucleolusChromosomesCell plate10 µm
41. Fig. 12-10aNucleusProphase1NucleolusChromatincondensing
42. Fig. 12-10bPrometaphase2Chromosomes
43. Fig. 12-10cMetaphase3
44. Fig. 12-10dAnaphase4
45. Fig. 12-10eTelophase5Cell plate10 µm
46. Binary FissionProkaryotes (bacteria and archaea) reproduce by
47. Fig. 12-11-1Origin ofreplicationTwo copiesof originE. coli cellBacterialchromosomePlasmamembraneCell wall
48. Fig. 12-11-2Origin ofreplicationTwo copiesof originE. coli cellBacterialchromosomePlasmamembraneCell wallOriginOrigin
49. Fig. 12-11-3Origin ofreplicationTwo copiesof originE. coli cellBacterialchromosomePlasmamembraneCell wallOriginOrigin
50. Fig. 12-11-4Origin ofreplicationTwo copiesof originE. coli cellBacterialchromosomePlasmamembraneCell wallOriginOrigin
51. The Evolution of MitosisSince prokaryotes evolved before
52. Fig. 12-12(a) BacteriaBacterialchromosomeChromosomesMicrotubulesIntact nuclearenvelope(b) DinoflagellatesKinetochoremicrotubuleIntact nuclearenvelope(c) Diatoms and yeastsKinetochoremicrotubuleFragments ofnuclear envelope(d) Most eukaryotes
53. Fig. 12-12abBacterialchromosomeChromosomesMicrotubules(a) Bacteria(b) DinoflagellatesIntact nuclearenvelope
54. Fig. 12-12cdKinetochoremicrotubule(c) Diatoms and yeastsKinetochoremicrotubule(d) Most eukaryotesFragments of nuclear envelopeIntact nuclearenvelope
55. Concept 12.3: The eukaryotic cell cycle is
56. Evidence for Cytoplasmic SignalsThe cell cycle appears
57. Fig. 12-13Experiment 1Experiment 2EXPERIMENTRESULTSSG1MG1MMSSWhen a cell in
58. The Cell Cycle Control SystemThe sequential events
59. Fig. 12-14SG1M checkpointG2MControlsystemG1 checkpointG2 checkpoint
60. For many cells, the G1 checkpoint seems
61. Fig. 12-15G1G0G1 checkpointCell receives a go-ahead
62. The Cell Cycle Clock: Cyclins and
63. Fig. 12-16Protein kinase activity (– )% of dividing cells (– )Time (min)3002004001000123453050002010RESULTS
64. Fig. 12-17MG1SG2MG1SG2MG1MPF activityCyclinconcentrationTime(a) Fluctuation of MPF activity
65. Fig. 12-17aTime(a) Fluctuation of MPF activity and cyclin concentration during the cell cycleCyclinconcentrationMPF activityMMMSSG1G1G1G2G2
66. Fig. 12-17bCyclin isdegradedCdkMPFCdkMSG1G2checkpointDegradedcyclinCyclin(b) Molecular mechanisms that help regulate the cell cycleG2Cyclin accumulation
67. Stop and Go Signs: Internal and External
68. Fig. 12-18PetriplateScalpelsCultured fibroblastsWithout PDGFcells fail to divideWith PDGFcells prolifer-ate10 µm
69. Another example of external signals is density-dependent
70. Fig. 12-19Anchorage dependenceDensity-dependent inhibitionDensity-dependent inhibition(a) Normal mammalian cells(b) Cancer cells25 µm25 µm
71. Cancer cells exhibit neither density-dependent inhibition nor
72. Loss of Cell Cycle Controls in Cancer
73. A normal cell is converted to a
74. Fig. 12-20TumorA tumor growsfrom a singlecancer cell.GlandulartissueLymphvesselBloodvesselMetastatictumorCancercellCancer
75. Fig. 12-UN1Telophase andCytokinesisAnaphaseMetaphasePrometaphaseProphaseMITOTIC (M) PHASECytokinesisMitosisSG1G2INTERPHASE
76. Fig. 12-UN2
77. Fig. 12-UN3
78. Fig. 12-UN4
79. Fig. 12-UN5
80. Fig. 12-UN6
81. You should now be able to:Describe the
82. Compare cytokinesis in animals and plantsDescribe the
83. Скачать презентанцию

Overview: The Key Roles of Cell DivisionThe ability of organisms to reproduce best distinguishes living things from nonliving matterThe continuity of life is based on the reproduction of cells, or cell

Слайды и текст этой презентации

Слайд 1Chapter 12
The Cell Cycle

Слайд 2Overview: The Key Roles of Cell Division
The ability of organisms

to reproduce best distinguishes living things from nonliving matter
The continuity

of life is based on the reproduction of cells, or cell division

Overview: The Key Roles of Cell DivisionThe ability of organisms to reproduce best distinguishes living things from

Слайд 3Fig. 12-1

Слайд 4In unicellular organisms, division of one cell reproduces the entire

organism
Multicellular organisms depend on cell division for:
Development from a fertilized

cell
Growth
Repair
Cell division is an integral part of the cell cycle, the life of a cell from formation to its own division

In unicellular organisms, division of one cell reproduces the entire organismMulticellular organisms depend on cell division for:Development

Слайд 5Fig. 12-2
100 µm
200 µm
20 µm
(a) Reproduction
(b) Growth and

development
(c) Tissue renewal

Слайд 6Fig. 12-2a
100 µm
(a) Reproduction

Слайд 7Fig. 12-2b
200 µm
(b) Growth and development

Слайд 8Fig. 12-2c
20 µm
(c) Tissue renewal

Слайд 9Concept 12.1: Cell division results in genetically identical daughter cells
Most

cell division results in daughter cells with identical genetic information,

DNA
A special type of division produces nonidentical daughter cells (gametes, or sperm and egg cells)

Concept 12.1: Cell division results in genetically identical daughter cellsMost cell division results in daughter cells

Слайд 10Cellular Organization of the Genetic Material
All the DNA in a

cell constitutes the cell’s genome
A genome can consist of a

single DNA molecule (common in prokaryotic cells) or a number of DNA molecules (common in eukaryotic cells)
DNA molecules in a cell are packaged into chromosomes

Cellular Organization of the Genetic MaterialAll the DNA in a cell constitutes the cell’s genomeA genome can

Слайд 11Fig. 12-3
20 µm

Слайд 12Every eukaryotic species has a characteristic number of chromosomes in

each cell nucleus
Somatic cells (nonreproductive cells) have two sets of

chromosomes
Gametes (reproductive cells: sperm and eggs) have half as many chromosomes as somatic cells
Eukaryotic chromosomes consist of chromatin, a complex of DNA and protein that condenses during cell division

Every eukaryotic species has a characteristic number of chromosomes in each cell nucleusSomatic cells (nonreproductive cells) have

Слайд 13Distribution of Chromosomes During Eukaryotic Cell Division
In preparation for cell

division, DNA is replicated and the chromosomes condense
Each duplicated chromosome

has two sister chromatids, which separate during cell division
The centromere is the narrow “waist” of the duplicated chromosome, where the two chromatids are most closely attached

Distribution of Chromosomes During Eukaryotic Cell DivisionIn preparation for cell division, DNA is replicated and the chromosomes

Слайд 14Fig. 12-4
0.5 µm
Chromosomes
Chromosome
duplication
(including DNA
synthesis)
Chromo-
some arm
Centromere
Sister
chromatids
DNA molecules
Separation of
sister chromatids
Centromere
Sister chromatids

Fig. 12-40.5 µmChromosomesChromosomeduplication(including DNAsynthesis)Chromo-some armCentromereSisterchromatidsDNA moleculesSeparation ofsister chromatidsCentromereSister chromatids

Слайд 15Eukaryotic cell division consists of:
Mitosis, the division of the nucleus
Cytokinesis,

the division of the cytoplasm
Gametes are produced by a variation

of cell division called meiosis
Meiosis yields nonidentical daughter cells that have only one set of chromosomes, half as many as the parent cell

Eukaryotic cell division consists of:Mitosis, the division of the nucleusCytokinesis, the division of the cytoplasmGametes are produced

Слайд 16Concept 12.2: The mitotic phase alternates with interphase in the cell

cycle
In 1882, the German anatomist Walther Flemming developed dyes to

observe chromosomes during mitosis and cytokinesis

Concept 12.2: The mitotic phase alternates with interphase in the cell cycleIn 1882, the German anatomist Walther

Слайд 17Phases of the Cell Cycle
The cell cycle consists of
Mitotic (M)

phase (mitosis and cytokinesis)
Interphase (cell growth and copying of chromosomes

in preparation for cell division)

Phases of the Cell CycleThe cell cycle consists ofMitotic (M) phase (mitosis and cytokinesis)Interphase (cell growth and

Слайд 18Interphase (about 90% of the cell cycle) can be divided

into subphases:
G1 phase (“first gap”)
S phase (“synthesis”)
G2 phase (“second gap”)
The

cell grows during all three phases, but chromosomes are duplicated only during the S phase

Interphase (about 90% of the cell cycle) can be divided into subphases: G1 phase (“first gap”)S phase (“synthesis”)G2

Слайд 19Fig. 12-5
S
(DNA synthesis)
MITOTIC
(M) PHASE
Mitosis
Cytokinesis
G1
G2
INTERPHASE

Слайд 20Mitosis is conventionally divided into five phases:
Prophase
Prometaphase
Metaphase
Anaphase
Telophase
Cytokinesis is well underway

by late telophase
BioFlix: Mitosis
Copyright © 2008 Pearson Education, Inc., publishing

as Pearson Benjamin Cummings

Mitosis is conventionally divided into five phases:ProphasePrometaphaseMetaphaseAnaphaseTelophaseCytokinesis is well underway by late telophaseBioFlix: MitosisCopyright © 2008 Pearson

Слайд 21Fig. 12-6
G2 of Interphase
Centrosomes
(with centriole
pairs)
Chromatin
(duplicated)
Nucleolus
Nuclear
envelope
Plasma
membrane
Early mitotic
spindle
Aster
Centromere
Chromosome, consisting
of two sister

chromatids
Prophase
Prometaphase
Fragments
of nuclear
envelope
Nonkinetochore
microtubules
Kinetochore
Kinetochore
microtubule
Metaphase
Metaphase
plate
Spindle
Centrosome at
one spindle pole
Anaphase
Daughter
chromosomes
Telophase and Cytokinesis
Cleavage
furrow
Nucleolus
forming
Nuclear
envelope
forming

Fig. 12-6G2 of InterphaseCentrosomes(with centriolepairs)Chromatin(duplicated)NucleolusNuclearenvelopePlasmamembraneEarly mitoticspindleAsterCentromereChromosome, consisting of two sister chromatidsProphasePrometaphaseFragmentsof nuclearenvelopeNonkinetochoremicrotubulesKinetochoreKinetochoremicrotubuleMetaphaseMetaphaseplateSpindleCentrosome atone spindle poleAnaphaseDaughterchromosomesTelophase and CytokinesisCleavagefurrowNucleolusformingNuclearenvelopeforming

Слайд 22Prophase
Fig. 12-6a
Prometaphase
G2 of Interphase

Слайд 23Fig. 12-6b
Prometaphase
Prophase
G2 of Interphase
Nonkinetochore
microtubules
Fragments
of nuclear
envelope
Aster
Centromere
Early mitotic
spindle
Chromatin
(duplicated)
Centrosomes
(with centriole
pairs)
Nucleolus
Nuclear
envelope
Plasma
membrane
Chromosome, consisting
of two sister

chromatids
Kinetochore
Kinetochore
microtubule

Fig. 12-6bPrometaphaseProphaseG2 of InterphaseNonkinetochoremicrotubulesFragmentsof nuclearenvelopeAsterCentromereEarly mitoticspindleChromatin(duplicated)Centrosomes(with centriolepairs)NucleolusNuclearenvelopePlasmamembraneChromosome, consistingof two sister chromatidsKinetochoreKinetochoremicrotubule

Слайд 24Fig. 12-6c
Metaphase
Anaphase
Telophase and Cytokinesis

Слайд 25Fig. 12-6d
Metaphase
Anaphase
Telophase and Cytokinesis
Cleavage
furrow
Nucleolus
forming
Metaphase
plate
Centrosome at
one spindle pole
Spindle
Daughter
chromosomes
Nuclear
envelope
forming

Fig. 12-6dMetaphaseAnaphaseTelophase and CytokinesisCleavagefurrowNucleolusformingMetaphaseplateCentrosome atone spindle poleSpindleDaughterchromosomesNuclearenvelopeforming

Слайд 26The Mitotic Spindle: A Closer Look
The mitotic spindle is an

apparatus of microtubules that controls chromosome movement during mitosis
During prophase,

assembly of spindle microtubules begins in the centrosome, the microtubule organizing center
The centrosome replicates, forming two centrosomes that migrate to opposite ends of the cell, as spindle microtubules grow out from them

The Mitotic Spindle: A Closer LookThe mitotic spindle is an apparatus of microtubules that controls chromosome movement

Слайд 27An aster (a radial array of short microtubules) extends from

each centrosome
The spindle includes the centrosomes, the spindle microtubules, and

the asters

An aster (a radial array of short microtubules) extends from each centrosomeThe spindle includes the centrosomes, the

Слайд 28During prometaphase, some spindle microtubules attach to the kinetochores of

chromosomes and begin to move the chromosomes
At metaphase, the

chromosomes are all lined up at the metaphase plate, the midway point between the spindle’s two poles

During prometaphase, some spindle microtubules attach to the kinetochores of chromosomes and begin to move the chromosomes

Слайд 29Fig. 12-7
Microtubules
Chromosomes
Sister
chromatids
Aster
Metaphase
plate
Centrosome
Kineto-
chores
Kinetochore
microtubules
Overlapping
nonkinetochore
microtubules
Centrosome
1 µm
0.5 µm

Fig. 12-7MicrotubulesChromosomesSisterchromatidsAsterMetaphaseplateCentrosomeKineto-choresKinetochoremicrotubulesOverlappingnonkinetochoremicrotubulesCentrosome1 µm0.5 µm

Слайд 30In anaphase, sister chromatids separate and move along the kinetochore

microtubules toward opposite ends of the cell
The microtubules shorten by

depolymerizing at their kinetochore ends

In anaphase, sister chromatids separate and move along the kinetochore microtubules toward opposite ends of the cellThe

Слайд 31Fig. 12-8
EXPERIMENT
Kinetochore
RESULTS
CONCLUSION
Spindle
pole
Mark
Chromosome
movement
Kinetochore
Microtubule
Motor
protein
Chromosome
Tubulin
subunits

Fig. 12-8EXPERIMENTKinetochoreRESULTSCONCLUSIONSpindlepoleMarkChromosomemovementKinetochoreMicrotubuleMotorproteinChromosomeTubulinsubunits

Слайд 32Fig. 12-8a
Kinetochore
Spindle
pole
Mark
EXPERIMENT
RESULTS

Слайд 33Fig. 12-8b
Kinetochore
Microtubule
Tubulin
Subunits
Chromosome
Chromosome
movement
Motor
protein
CONCLUSION

Слайд 34Nonkinetochore microtubules from opposite poles overlap and push against each

other, elongating the cell
In telophase, genetically identical daughter nuclei form

at opposite ends of the cell

Nonkinetochore microtubules from opposite poles overlap and push against each other, elongating the cellIn telophase, genetically identical

Слайд 35Cytokinesis: A Closer Look
In animal cells, cytokinesis occurs by a

process known as cleavage, forming a cleavage furrow
In plant cells,

a cell plate forms during cytokinesis

Animation: Cytokinesis

Cytokinesis: A Closer LookIn animal cells, cytokinesis occurs by a process known as cleavage, forming a cleavage

Слайд 36Video: Sea Urchin (Time Lapse)
Video: Animal Mitosis
Copyright © 2008 Pearson

Education, Inc., publishing as Pearson Benjamin Cummings

Слайд 37Fig. 12-9
Cleavage furrow
100 µm
Contractile ring of
microfilaments
Daughter cells
(a) Cleavage of an

animal cell (SEM)
(b) Cell plate formation in a plant cell

(TEM)

Vesicles
forming
cell plate

Wall of
parent cell

Cell plate

Daughter cells

New cell wall

1 µm

Fig. 12-9Cleavage furrow100 µmContractile ring ofmicrofilamentsDaughter cells(a) Cleavage of an animal cell (SEM)(b) Cell plate formation in

Слайд 38Cleavage furrow
Fig. 12-9a
100 µm
Daughter cells
(a) Cleavage of an animal cell

(SEM)
Contractile ring of
microfilaments

Слайд 39Fig. 12-9b
Daughter cells
(b) Cell plate formation in a plant cell

(TEM)
Vesicles
forming
cell plate
Wall of
parent cell
New cell wall
Cell plate
1 µm

Fig. 12-9bDaughter cells(b) Cell plate formation in a plant cell (TEM)Vesiclesformingcell plateWall ofparent cellNew cell wallCell plate1

Слайд 40Fig. 12-10
Chromatin
condensing
Metaphase
Anaphase
Telophase
Prometaphase
Nucleus
Prophase
1
2
3
5
4
Nucleolus
Chromosomes
Cell plate
10 µm

Fig. 12-10ChromatincondensingMetaphaseAnaphaseTelophasePrometaphaseNucleusProphase12354NucleolusChromosomesCell plate10 µm

Слайд 41Fig. 12-10a
Nucleus
Prophase
1
Nucleolus
Chromatin
condensing

Слайд 42Fig. 12-10b
Prometaphase
2
Chromosomes

Слайд 43Fig. 12-10c
Metaphase
3

Слайд 44Fig. 12-10d
Anaphase
4

Слайд 45Fig. 12-10e
Telophase
5
Cell plate
10 µm

Слайд 46Binary Fission
Prokaryotes (bacteria and archaea) reproduce by a type of

cell division called binary fission
In binary fission, the chromosome replicates

(beginning at the origin of replication), and the two daughter chromosomes actively move apart

Binary FissionProkaryotes (bacteria and archaea) reproduce by a type of cell division called binary fissionIn binary fission,

Слайд 47Fig. 12-11-1
Origin of
replication
Two copies
of origin
E. coli cell
Bacterial
chromosome
Plasma
membrane
Cell wall

Слайд 48Fig. 12-11-2
Origin of
replication
Two copies
of origin
E. coli cell
Bacterial
chromosome
Plasma
membrane
Cell wall
Origin
Origin

Слайд 49Fig. 12-11-3
Origin of
replication
Two copies
of origin
E. coli cell
Bacterial
chromosome
Plasma
membrane
Cell wall
Origin
Origin

Слайд 50Fig. 12-11-4
Origin of
replication
Two copies
of origin
E. coli cell
Bacterial
chromosome
Plasma
membrane
Cell wall
Origin
Origin

Слайд 51The Evolution of Mitosis
Since prokaryotes evolved before eukaryotes, mitosis probably

evolved from binary fission
Certain protists exhibit types of cell division

that seem intermediate between binary fission and mitosis

The Evolution of MitosisSince prokaryotes evolved before eukaryotes, mitosis probably evolved from binary fissionCertain protists exhibit types

Слайд 52Fig. 12-12
(a) Bacteria
Bacterial
chromosome
Chromosomes
Microtubules
Intact nuclear
envelope
(b) Dinoflagellates
Kinetochore
microtubule
Intact nuclear
envelope
(c) Diatoms and yeasts
Kinetochore
microtubule
Fragments of
nuclear

envelope
(d) Most eukaryotes

Fig. 12-12(a) BacteriaBacterialchromosomeChromosomesMicrotubulesIntact nuclearenvelope(b) DinoflagellatesKinetochoremicrotubuleIntact nuclearenvelope(c) Diatoms and yeastsKinetochoremicrotubuleFragments ofnuclear envelope(d) Most eukaryotes

Слайд 53Fig. 12-12ab
Bacterial
chromosome
Chromosomes
Microtubules
(a) Bacteria
(b) Dinoflagellates
Intact nuclear
envelope

Слайд 54Fig. 12-12cd
Kinetochore
microtubule
(c) Diatoms and yeasts
Kinetochore
microtubule
(d) Most eukaryotes
Fragments of
nuclear envelope
Intact

nuclear
envelope

Слайд 55Concept 12.3: The eukaryotic cell cycle is regulated by a

molecular control system
The frequency of cell division varies with the

type of cell
These cell cycle differences result from regulation at the molecular level

Concept 12.3: The eukaryotic cell cycle is regulated by a molecular control systemThe frequency of cell division

Слайд 56Evidence for Cytoplasmic Signals
The cell cycle appears to be driven

by specific chemical signals present in the cytoplasm
Some evidence for

this hypothesis comes from experiments in which cultured mammalian cells at different phases of the cell cycle were fused to form a single cell with two nuclei

Evidence for Cytoplasmic SignalsThe cell cycle appears to be driven by specific chemical signals present in the

Слайд 57Fig. 12-13
Experiment 1
Experiment 2
EXPERIMENT
RESULTS
S
G1
M
G1
M
M
S
S
When a cell in the
S phase was

fused
with a cell in G1, the G1
nucleus immediately
entered

the S
phase—DNA was
synthesized.

When a cell in the
M phase was fused with
a cell in G1, the G1
nucleus immediately
began mitosis—a
spindle formed and
chromatin condensed,
even though the
chromosome had not
been duplicated.

Fig. 12-13Experiment 1Experiment 2EXPERIMENTRESULTSSG1MG1MMSSWhen a cell in theS phase was fused with a cell in G1, the

Слайд 58The Cell Cycle Control System
The sequential events of the cell

cycle are directed by a distinct cell cycle control system,

which is similar to a clock
The cell cycle control system is regulated by both internal and external controls
The clock has specific checkpoints where the cell cycle stops until a go-ahead signal is received

The Cell Cycle Control SystemThe sequential events of the cell cycle are directed by a distinct cell

Слайд 59Fig. 12-14
S
G1
M checkpoint
G2
M
Control
system
G1 checkpoint
G2 checkpoint

Слайд 60For many cells, the G1 checkpoint seems to be the

most important one
If a cell receives a go-ahead signal at

the G1 checkpoint, it will usually complete the S, G2, and M phases and divide
If the cell does not receive the go-ahead signal, it will exit the cycle, switching into a nondividing state called the G0 phase

For many cells, the G1 checkpoint seems to be the most important oneIf a cell receives a

Слайд 61Fig. 12-15
G1
G0
G1 checkpoint
Cell receives a go-ahead
signal
G1
(b) Cell

does not receive a
go-ahead signal

Fig. 12-15G1G0G1 checkpointCell receives a go-ahead signalG1(b) Cell does not receive a go-ahead

Слайд 62The Cell Cycle Clock: Cyclins and Cyclin-Dependent Kinases
Two types of

regulatory proteins are involved in cell cycle control: cyclins and

cyclin-dependent kinases (Cdks)
The activity of cyclins and Cdks fluctuates during the cell cycle
MPF (maturation-promoting factor) is a cyclin-Cdk complex that triggers a cell’s passage past the G2 checkpoint into the M phase

The Cell Cycle Clock: Cyclins and Cyclin-Dependent KinasesTwo types of regulatory proteins are involved in cell

Слайд 63Fig. 12-16
Protein kinase activity (– )
% of dividing cells (–

)
Time (min)
300
200
400
100
0
1
2
3
4
5
30
500
0
20
10
RESULTS

Слайд 64Fig. 12-17
M
G1
S
G2
M
G1
S
G2
M
G1
MPF activity
Cyclin
concentration
Time
(a) Fluctuation of MPF activity and cyclin concentration

during
the cell cycle
Degraded
cyclin
Cdk
G1
S
G2
M
Cdk
G2
checkpoint
Cyclin is
degraded
Cyclin
MPF
(b) Molecular mechanisms that

help regulate the cell cycle

Cyclin accumulation

Fig. 12-17MG1SG2MG1SG2MG1MPF activityCyclinconcentrationTime(a) Fluctuation of MPF activity and cyclin concentration during the cell cycleDegradedcyclinCdkG1SG2MCdkG2checkpointCyclin isdegradedCyclinMPF(b)

Слайд 65Fig. 12-17a
Time
(a) Fluctuation of MPF activity and cyclin concentration during

the cell cycle
Cyclin
concentration
MPF activity
M
M
M
S
S
G1
G1
G1
G2
G2

Fig. 12-17aTime(a) Fluctuation of MPF activity and cyclin concentration during the cell cycleCyclinconcentrationMPF activityMMMSSG1G1G1G2G2

Слайд 66Fig. 12-17b
Cyclin is
degraded
Cdk
MPF
Cdk
M
S
G1
G2
checkpoint
Degraded
cyclin
Cyclin
(b) Molecular mechanisms that help regulate the cell

cycle
G2
Cyclin accumulation

Fig. 12-17bCyclin isdegradedCdkMPFCdkMSG1G2checkpointDegradedcyclinCyclin(b) Molecular mechanisms that help regulate the cell cycleG2Cyclin accumulation

Слайд 67Stop and Go Signs: Internal and External Signals at the

Checkpoints
An example of an internal signal is that kinetochores not

attached to spindle microtubules send a molecular signal that delays anaphase
Some external signals are growth factors, proteins released by certain cells that stimulate other cells to divide
For example, platelet-derived growth factor (PDGF) stimulates the division of human fibroblast cells in culture

Stop and Go Signs: Internal and External Signals at the CheckpointsAn example of an internal signal is

Слайд 68Fig. 12-18
Petri
plate
Scalpels
Cultured fibroblasts
Without PDGF
cells fail to divide
With PDGF
cells prolifer-
ate
10 µm

Слайд 69Another example of external signals is density-dependent inhibition, in which

crowded cells stop dividing
Most animal cells also exhibit anchorage dependence,

in which they must be attached to a substratum in order to divide

Another example of external signals is density-dependent inhibition, in which crowded cells stop dividingMost animal cells also

Слайд 70Fig. 12-19
Anchorage dependence
Density-dependent inhibition
Density-dependent inhibition
(a) Normal mammalian cells
(b) Cancer cells
25

µm
25 µm

2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings

Cancer cells exhibit neither density-dependent inhibition nor anchorage dependenceCopyright © 2008 Pearson Education, Inc., publishing as Pearson

Слайд 72Loss of Cell Cycle Controls in Cancer Cells
Cancer cells do

not respond normally to the body’s control mechanisms
Cancer cells may

not need growth factors to grow and divide:
They may make their own growth factor
They may convey a growth factor’s signal without the presence of the growth factor
They may have an abnormal cell cycle control system

Loss of Cell Cycle Controls in Cancer CellsCancer cells do not respond normally to the body’s control

Слайд 73A normal cell is converted to a cancerous cell by

a process called transformation
Cancer cells form tumors, masses of abnormal

cells within otherwise normal tissue
If abnormal cells remain at the original site, the lump is called a benign tumor
Malignant tumors invade surrounding tissues and can metastasize, exporting cancer cells to other parts of the body, where they may form secondary tumors

A normal cell is converted to a cancerous cell by a process called transformationCancer cells form tumors,

Слайд 74Fig. 12-20
Tumor
A tumor grows
from a single
cancer cell.
Glandular
tissue
Lymph
vessel
Blood
vessel
Metastatic
tumor
Cancer
cell
Cancer cells
invade neigh-
boring tissue.
Cancer

cells spread
to other parts of
the body.
Cancer cells may
survive and
establish a

new
tumor in another
part of the body.

Fig. 12-20TumorA tumor growsfrom a singlecancer cell.GlandulartissueLymphvesselBloodvesselMetastatictumorCancercellCancer cellsinvade neigh-boring tissue.Cancer cells spreadto other parts ofthe body.Cancer cells

Слайд 75Fig. 12-UN1
Telophase and
Cytokinesis
Anaphase
Metaphase
Prometaphase
Prophase
MITOTIC (M) PHASE
Cytokinesis
Mitosis
S
G1
G2
INTERPHASE

Fig. 12-UN1Telophase andCytokinesisAnaphaseMetaphasePrometaphaseProphaseMITOTIC (M) PHASECytokinesisMitosisSG1G2INTERPHASE

Слайд 76Fig. 12-UN2

Слайд 77Fig. 12-UN3

Слайд 78Fig. 12-UN4

Слайд 79Fig. 12-UN5

Слайд 80Fig. 12-UN6

Слайд 81You should now be able to:
Describe the structural organization of

the prokaryotic genome and the eukaryotic genome
List the phases of

the cell cycle; describe the sequence of events during each phase
List the phases of mitosis and describe the events characteristic of each phase
Draw or describe the mitotic spindle, including centrosomes, kinetochore microtubules, nonkinetochore microtubules, and asters

You should now be able to:Describe the structural organization of the prokaryotic genome and the eukaryotic genomeList

Слайд 82Compare cytokinesis in animals and plants
Describe the process of binary

fission in bacteria and explain how eukaryotic mitosis may have

evolved from binary fission
Explain how the abnormal cell division of cancerous cells escapes normal cell cycle controls
Distinguish between benign, malignant, and metastatic tumors

Compare cytokinesis in animals and plantsDescribe the process of binary fission in bacteria and explain how eukaryotic

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Chapter 12

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Слайд 1Chapter 12The Cell Cycle

Слайд 2Overview: The Key Roles of Cell DivisionThe ability of organisms

to reproduce best distinguishes living things from nonliving matterThe continuity

Слайд 3Fig. 12-1

Слайд 4In unicellular organisms, division of one cell reproduces the entire

organismMulticellular organisms depend on cell division for:Development from a fertilized

Слайд 5Fig. 12-2100 µm200 µm20 µm(a) Reproduction(b) Growth and

development(c) Tissue renewal

Слайд 6Fig. 12-2a100 µm(a) Reproduction

Слайд 7Fig. 12-2b200 µm(b) Growth and development

Слайд 8Fig. 12-2c20 µm(c) Tissue renewal

Слайд 9Concept 12.1: Cell division results in genetically identical daughter cellsMost

cell division results in daughter cells with identical genetic information,

Слайд 10Cellular Organization of the Genetic MaterialAll the DNA in a

cell constitutes the cell’s genomeA genome can consist of a

Слайд 11Fig. 12-320 µm

Слайд 12Every eukaryotic species has a characteristic number of chromosomes in

each cell nucleusSomatic cells (nonreproductive cells) have two sets of

Слайд 13Distribution of Chromosomes During Eukaryotic Cell DivisionIn preparation for cell

division, DNA is replicated and the chromosomes condenseEach duplicated chromosome

Слайд 14Fig. 12-40.5 µmChromosomesChromosomeduplication(including DNAsynthesis)Chromo-some armCentromereSisterchromatidsDNA moleculesSeparation ofsister chromatidsCentromereSister chromatids

Слайд 15Eukaryotic cell division consists of:Mitosis, the division of the nucleusCytokinesis,

the division of the cytoplasmGametes are produced by a variation

Слайд 16Concept 12.2: The mitotic phase alternates with interphase in the cell

cycleIn 1882, the German anatomist Walther Flemming developed dyes to

Слайд 17Phases of the Cell CycleThe cell cycle consists ofMitotic (M)

phase (mitosis and cytokinesis)Interphase (cell growth and copying of chromosomes

Слайд 18Interphase (about 90% of the cell cycle) can be divided

into subphases: G1 phase (“first gap”)S phase (“synthesis”)G2 phase (“second gap”)The

Слайд 19Fig. 12-5S(DNA synthesis)MITOTIC(M) PHASEMitosisCytokinesisG1G2INTERPHASE

Слайд 20Mitosis is conventionally divided into five phases:ProphasePrometaphaseMetaphaseAnaphaseTelophaseCytokinesis is well underway

by late telophaseBioFlix: MitosisCopyright © 2008 Pearson Education, Inc., publishing

Слайд 21Fig. 12-6G2 of InterphaseCentrosomes(with centriolepairs)Chromatin(duplicated)NucleolusNuclearenvelopePlasmamembraneEarly mitoticspindleAsterCentromereChromosome, consisting of two sister

chromatidsProphasePrometaphaseFragmentsof nuclearenvelopeNonkinetochoremicrotubulesKinetochoreKinetochoremicrotubuleMetaphaseMetaphaseplateSpindleCentrosome atone spindle poleAnaphaseDaughterchromosomesTelophase and CytokinesisCleavagefurrowNucleolusformingNuclearenvelopeforming

Слайд 22ProphaseFig. 12-6aPrometaphaseG2 of Interphase

Слайд 23Fig. 12-6bPrometaphaseProphaseG2 of InterphaseNonkinetochoremicrotubulesFragmentsof nuclearenvelopeAsterCentromereEarly mitoticspindleChromatin(duplicated)Centrosomes(with centriolepairs)NucleolusNuclearenvelopePlasmamembraneChromosome, consistingof two sister

chromatidsKinetochoreKinetochoremicrotubule

Слайд 24Fig. 12-6cMetaphaseAnaphaseTelophase and Cytokinesis

Слайд 25Fig. 12-6dMetaphaseAnaphaseTelophase and CytokinesisCleavagefurrowNucleolusformingMetaphaseplateCentrosome atone spindle poleSpindleDaughterchromosomesNuclearenvelopeforming

Слайд 26The Mitotic Spindle: A Closer LookThe mitotic spindle is an

apparatus of microtubules that controls chromosome movement during mitosisDuring prophase,