Chapter 12. The Cell Cycle презентация

Содержание

1. Chapter 12. The Cell Cycle
2. Overview: The Key Roles of Cell Division
3. Fig. 12-1
4. In unicellular organisms, division of one cell
5. Fig. 12-2 100 µm 200 µm 20
6. Fig. 12-2a 100 µm (a) Reproduction
7. Fig. 12-2b 200 µm (b) Growth and development
8. Fig. 12-2c 20 µm (c) Tissue renewal
9. Concept 12.1: Cell division results in genetically
10. Cellular Organization of the Genetic Material All
11. Fig. 12-3 20 µm
12. Every eukaryotic species has a characteristic number
13. Distribution of Chromosomes During Eukaryotic Cell Division
14. Fig. 12-4 0.5 µm Chromosomes Chromosome duplication
15. Eukaryotic cell division consists of: Mitosis, the
16. Concept 12.2: The mitotic phase alternates with
17. Phases of the Cell Cycle The cell
18. Interphase (about 90% of the cell cycle)
19. Fig. 12-5 S (DNA synthesis) MITOTIC (M) PHASE Mitosis Cytokinesis G1 G2 INTERPHASE
20. Mitosis is conventionally divided into five phases:
21. Fig. 12-6
22. Prophase Fig. 12-6a Prometaphase G2 of Interphase
23. Fig. 12-6b Prometaphase Prophase
24. Fig. 12-6c Metaphase Anaphase Telophase and Cytokinesis
25. Fig. 12-6d Metaphase Anaphase
26. The Mitotic Spindle: A Closer Look The
27. An aster (a radial array of short
28. During prometaphase, some spindle microtubules attach to
29. Fig. 12-7 Microtubules Chromosomes Sister chromatids Aster
30. In anaphase, sister chromatids separate and move
31. Fig. 12-8 EXPERIMENT Kinetochore
32. Fig. 12-8a Kinetochore Spindle pole Mark EXPERIMENT RESULTS
33. Fig. 12-8b Kinetochore Microtubule Tubulin Subunits Chromosome Chromosome movement Motor protein CONCLUSION
34. Nonkinetochore microtubules from opposite poles overlap and
35. Cytokinesis: A Closer Look In animal cells,
36. Video: Sea Urchin (Time Lapse) Video: Animal
37. Fig. 12-9 Cleavage furrow 100 µm Contractile
38. Cleavage furrow Fig. 12-9a 100 µm Daughter
39. Fig. 12-9b Daughter cells (b) Cell plate
40. Fig. 12-10 Chromatin condensing Metaphase Anaphase Telophase
41. Fig. 12-10a Nucleus Prophase 1 Nucleolus Chromatin condensing
42. Fig. 12-10b Prometaphase 2 Chromosomes
43. Fig. 12-10c Metaphase 3
44. Fig. 12-10d Anaphase 4
45. Fig. 12-10e Telophase 5 Cell plate 10 µm
46. Binary Fission Prokaryotes (bacteria and archaea) reproduce
47. Fig. 12-11-1 Origin of replication Two copies
48. Fig. 12-11-2 Origin of replication Two copies
49. Fig. 12-11-3 Origin of replication Two copies
50. Fig. 12-11-4 Origin of replication Two copies
51. The Evolution of Mitosis Since prokaryotes evolved
52. Fig. 12-12 (a) Bacteria Bacterial chromosome Chromosomes
53. Fig. 12-12ab Bacterial chromosome Chromosomes Microtubules (a) Bacteria (b) Dinoflagellates Intact nuclear envelope
54. Fig. 12-12cd Kinetochore microtubule (c) Diatoms and
55. Concept 12.3: The eukaryotic cell cycle is
56. Evidence for Cytoplasmic Signals The cell cycle
57. Fig. 12-13 Experiment 1 Experiment 2
58. The Cell Cycle Control System The sequential
59. Fig. 12-14 S G1 M checkpoint G2 M Control system G1 checkpoint G2 checkpoint
60. For many cells, the G1 checkpoint seems
61. Fig. 12-15 G1 G0 G1 checkpoint Cell
62. The Cell Cycle Clock: Cyclins and
63. Fig. 12-16 Protein kinase activity (– )
64. Fig. 12-17 M G1 S G2 M
65. Fig. 12-17a Time (a) Fluctuation of MPF
66. Fig. 12-17b Cyclin is degraded Cdk MPF
67. Stop and Go Signs: Internal and External
68. Fig. 12-18 Petri plate Scalpels Cultured fibroblasts
69. Another example of external signals is density-dependent
70. Fig. 12-19 Anchorage dependence Density-dependent inhibition Density-dependent
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. 12-20 Tumor
75. Fig. 12-UN1 Telophase and Cytokinesis Anaphase Metaphase
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
82. Compare cytokinesis in animals and plants Describe

Overview: 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,

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

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

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)

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

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

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

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

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

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

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)

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

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

Слайд 21

Fig. 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

Слайд 22

Prophase

Fig. 12-6a
Prometaphase
G2 of Interphase

Слайд 23

Fig. 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

Слайд 24

Fig. 12-6c
Metaphase
Anaphase
Telophase and Cytokinesis

Слайд 25

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

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

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

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

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

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

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

Слайд 31

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

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

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

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

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

Слайд 40Fig. 12-10
Chromatin
condensing
Metaphase
Anaphase
Telophase
Prometaphase
Nucleus
Prophase

1

2

3

5

4
Nucleolus
Chromosomes
Cell plate
10 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

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

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

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

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

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.

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

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

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

not receive a
go-ahead signal

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

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

(min)

300

200

400

100

500

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

checkpoint

Cyclin is
degraded

Cyclin

MPF

(b) Molecular mechanisms that help regulate the cell cycle

Cyclin accumulation

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

the cell cycle

Cyclin
concentration

MPF activity

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

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

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

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

µm

Pearson Education, Inc., publishing as Pearson Benjamin Cummings

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

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

Слайд 74

Fig. 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.

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

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

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

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Chapter 12. The Cell Cycle презентация

Содержание

Слайд 1Chapter 12The Cell Cycle

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

Слайд 3Fig. 12-1

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

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

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

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

Слайд 11Fig. 12-320 µm

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

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

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

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

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

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

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

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

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

Слайд 22ProphaseFig. 12-6aPrometaphaseG2 of Interphase

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

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

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

Слайд 29Fig. 12-7MicrotubulesChromosomesSisterchromatidsAsterMetaphaseplateCentrosomeKineto-choresKinetochoremicrotubulesOverlappingnonkinetochoremicrotubulesCentrosome1 µm0.5 µm

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

Слайд 31Fig. 12-8EXPERIMENTKinetochoreRESULTSCONCLUSIONSpindlepoleMarkChromosomemovementKinetochoreMicrotubuleMotorproteinChromosomeTubulinsubunits

Слайд 32Fig. 12-8aKinetochoreSpindlepoleMarkEXPERIMENTRESULTS

Слайд 33Fig. 12-8bKinetochoreMicrotubuleTubulinSubunitsChromosomeChromosomemovementMotorproteinCONCLUSION

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

Слайд 35Cytokinesis: A Closer LookIn animal cells, cytokinesis occurs by a process

Слайд 36Video: Sea Urchin (Time Lapse)Video: Animal MitosisCopyright © 2008 Pearson Education,

Слайд 37Fig. 12-9Cleavage furrow100 µmContractile ring ofmicrofilamentsDaughter cells(a) Cleavage of an animal

Слайд 38Cleavage furrowFig. 12-9a100 µmDaughter cells(a) Cleavage of an animal cell (SEM)Contractile

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

Слайд 40Fig. 12-10ChromatincondensingMetaphaseAnaphaseTelophasePrometaphaseNucleusProphase12354NucleolusChromosomesCell plate10 µm

Слайд 41Fig. 12-10aNucleusProphase1NucleolusChromatincondensing

Слайд 42Fig. 12-10bPrometaphase2Chromosomes

Слайд 43Fig. 12-10cMetaphase3

Слайд 44Fig. 12-10dAnaphase4

Слайд 45Fig. 12-10eTelophase5Cell plate10 µm

Слайд 46Binary FissionProkaryotes (bacteria and archaea) reproduce by a type of cell

Слайд 47Fig. 12-11-1Origin ofreplicationTwo copiesof originE. coli cellBacterialchromosomePlasmamembraneCell wall

Слайд 48Fig. 12-11-2Origin ofreplicationTwo copiesof originE. coli cellBacterialchromosomePlasmamembraneCell wallOriginOrigin

Слайд 49Fig. 12-11-3Origin ofreplicationTwo copiesof originE. coli cellBacterialchromosomePlasmamembraneCell wallOriginOrigin

Слайд 50Fig. 12-11-4Origin ofreplicationTwo copiesof originE. coli cellBacterialchromosomePlasmamembraneCell wallOriginOrigin

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

Слайд 52Fig. 12-12(a) BacteriaBacterialchromosomeChromosomesMicrotubulesIntact nuclearenvelope(b) DinoflagellatesKinetochoremicrotubuleIntact nuclearenvelope(c) Diatoms and yeastsKinetochoremicrotubuleFragments ofnuclear envelope(d)

Слайд 53Fig. 12-12abBacterialchromosomeChromosomesMicrotubules(a) Bacteria(b) DinoflagellatesIntact nuclearenvelope

Слайд 54Fig. 12-12cdKinetochoremicrotubule(c) Diatoms and yeastsKinetochoremicrotubule(d) Most eukaryotesFragments of nuclear envelopeIntact nuclearenvelope