Slide 1 Chapter 12: The Cell Cycle. Slide 2 Fig. 12-1 The Cell Cycle.
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Transcript of Slide 1 Chapter 12: The Cell Cycle. Slide 2 Fig. 12-1 The Cell Cycle.
Slide 1
Chapter 12:Chapter 12:
The Cell CycleThe Cell Cycle
Slide 2Fig. 12-1
The Cell CycleThe Cell Cycle
Figure 12.2
(a) Reproduction
(b) Growth and development
(c) Tissue renewal20 m
100 m
200 m
Why do Why do cells cells
divide?divide?
Figure 12.3
20 m
Eukaryotes Have ChromosomesEukaryotes Have Chromosomes
Figure 12.4
0.5 mCentromere
Sisterchromatids
Chromosomes are duplicated Chromosomes are duplicated before cell division!before cell division!
Figure 12.5-1
ChromosomesChromosomal
DNA molecules
Centromere
Chromosomearm
1
Figure 12.5-2
ChromosomesChromosomal
DNA molecules
Centromere
Chromosomearm
Chromosome duplication(including DNA replication)
and condensation
Sisterchromatids
1
2
Figure 12.5-3
ChromosomesChromosomal
DNA molecules
Centromere
Chromosomearm
Chromosome duplication(including DNA replication)
and condensation
Sisterchromatids
Separation of sisterchromatids into
two chromosomes
1
2
3
Slide 9
Chromosome arrangementChromosome arrangement
• Somatic cells – typical body cells Somatic cells – typical body cells
• 46 chromosomes in 23 pairs (humans)46 chromosomes in 23 pairs (humans)
• The chromosomes are not normally The chromosomes are not normally paired uppaired up
• Each pair is called homologous Each pair is called homologous chromosomeschromosomes
• Gametes – sex cellsGametes – sex cells
• 23 chromosomes (humans)23 chromosomes (humans)
• One member from each pairOne member from each pair
Slide 10
Homologous chromosomesHomologous chromosomes
• 22 of the pairs (autosomes) are “true 22 of the pairs (autosomes) are “true homologues”homologues”
• One of each came from mom and dadOne of each came from mom and dad
• Identical in length and type of genes carriedIdentical in length and type of genes carried
• Genes on each are slightly differentGenes on each are slightly different
• Sex chromosomes (23rd pair) don’t match Sex chromosomes (23rd pair) don’t match up exactly (X vs Y)up exactly (X vs Y)
Figure 13.3b
Pair of homologousduplicated chromosomes
Centromere
Sisterchromatids
Metaphasechromosome
5 m
Figure 12.6
INTERPHASE
G1
G2
S(DNA synthesis)
MITOTIC(M) PHASE
Cytokinesis
Mito
sis
The Cell CycleThe Cell Cycle
Slide 13
MitosisMitosis
• Division of the nucleusDivision of the nucleus
• Results in two nuclei that have the same Results in two nuclei that have the same chromosome number as the parentchromosome number as the parent
• The two nuclei are genetically identicalThe two nuclei are genetically identical
Slide 14
MitosisMitosis• Divided into 5 phases:Divided into 5 phases:
1.1. ProphaseProphase
2.2. PrometaphasePrometaphase
3.3. MetaphaseMetaphase
4.4. AnaphaseAnaphase
5.5. TelophaseTelophase
• Phases are determined by chromosome Phases are determined by chromosome movementmovement
• Chromosome movement determined by Chromosome movement determined by mitotic spindlemitotic spindle
• Mitotic spindle controlled by centrosomeMitotic spindle controlled by centrosome
Figure 12.8
Sisterchromatids
AsterCentrosome
Metaphaseplate
(imaginary)
Kineto-chores
Overlappingnonkinetochore
microtubules Kinetochoremicrotubules
Microtubules
Chromosomes
Centrosome
0.5 m
1 m
The Mitotic SpindleThe Mitotic Spindle
Figure 12.7a
G2 of Interphase Prophase Prometaphase
Centrosomes(with centriole
pairs)Chromatin
(duplicated)
NucleolusNuclear
envelope
Plasmamembrane
Early mitoticspindle
Aster
Centromere
Chromosome, consistingof two sister chromatids
Fragments of nuclearenvelope
Nonkinetochoremicrotubules
Kinetochore Kinetochoremicrotubule
Figure 12.7b
Metaphase
Metaphase plate
Anaphase Telophase and Cytokinesis
Spindle Centrosome atone spindle pole
Daughterchromosomes
Cleavagefurrow
Nucleolusforming
Nuclearenvelopeforming
Figure 12.7c
G2 of Interphase Prophase Prometaphase
10
m
Figure 12.7d
10
m
Metaphase Anaphase Telophase and Cytokinesis
Figure 12.11
ChromatincondensingNucleus
Nucleolus Chromosomes Cell plate10 m
Prophase Prometaphase Metaphase Anaphase Telophase1 2 3 4 5
Mitosis in a Plant CellMitosis in a Plant Cell
Figure 12.10
(a) Cleavage of an animal cell (SEM) (b) Cell plate formation in a plant cell (TEM)
Cleavage furrow
Contractile ring ofmicrofilaments
Daughter cells
Vesiclesformingcell plate
Wall of parent cell
Cell plate New cell wall
Daughter cells
100 m
1 m
Cytokenesis: Animal vs. Plant CellCytokenesis: Animal vs. Plant Cell
Figure 12.11
Binary Fission: Cell division in Binary Fission: Cell division in bacteriabacteria
Figure 12.12-1
1
Origin ofreplication
E. coli cell
Two copies of origin
Cell wall
Plasma membrane
Bacterial chromosome
Chromosomereplication
begins.
Figure 12.12-2
1
Origin ofreplication
E. coli cell
Two copies of origin
Cell wall
Plasma membrane
Bacterial chromosome
Origin Origin
Chromosomereplication
begins.
Replicationcontinues.
2
Figure 12.12-3
1
Origin ofreplication
E. coli cell
Two copies of origin
Cell wall
Plasma membrane
Bacterial chromosome
Origin Origin
Chromosomereplication
begins.
Replicationcontinues.
Replicationfinishes.
2
3
Figure 12.12-4
1
Origin ofreplication
E. coli cell
Two copies of origin
Cell wall
Plasma membrane
Bacterial chromosome
Origin Origin
Chromosomereplication
begins.
Replicationcontinues.
Replicationfinishes.
Two daughtercells result.
2
3
4
Slide 27LE 8-3b
Prokaryotic chromosomes
Co
lori
zed
TE
M 3
2,5
00
Figure 12.15
G1 checkpoint
G1
G2
G2 checkpointM checkpoint
M
SControlsystem
Cell
Cycl
e
Cell
Cycl
e
Contr
ol
Contr
ol
Figure 12.16
G1 checkpoint
G1 G1
G0
(a) Cell receives a go-ahead signal.
(b) Cell does not receive a go-ahead signal.
CheckpointsCheckpoints
Slide 30
CancerCancer
• Kills 1 out of 5 AmericansKills 1 out of 5 Americans
• Disease of the cell cycleDisease of the cell cycle
• Cells don’t respond to the normal cell cycle Cells don’t respond to the normal cell cycle checkpointscheckpoints
• Cancer cells DO NOT exhibit density or Cancer cells DO NOT exhibit density or anchorage dependenceanchorage dependence
• Cancer cells divide out of control and can Cancer cells divide out of control and can invade other parts of the bodyinvade other parts of the body
Figure 12.19
Anchorage dependence
Density-dependent inhibition
Density-dependent inhibition
(a) Normal mammalian cells (b) Cancer cells
20 m 20 m
Figure 12.20
Glandulartissue
Tumor
Lymph vesselBloodvessel
Cancercell
Metastatictumor
A tumor growsfrom a singlecancer cell.
Cancer cells invade neighboring
tissue.
Cancer cells spreadthrough lymph andblood vessels to other parts of the
body.
Cancer cells may survive and establisha new tumor
in another part of the body.
4321
Figure 12.UN01
Mitosis
Cytokinesis
MITOTIC (M) PHASE
G1
G2
S
Telophase andCytokinesis
AnaphaseMetaphase
Prometaphase
Prophase
I T R HASEE PN
Figure 12.UN05
Figure 12.UN04