52ch11mitosis2008 2.original 2

8/13/2019 52Ch11mitosis2008 2.Original 2

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AP Biology 2007-2008

The Cell Cycle:Cell Growth, Cell Division


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Where it all began

You started as a cell smaller thana period at the end of a sentence


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Going from egg to baby.the original fertilized egg has to divide

and divide

and divide

and divide

Getting from there to here


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For reproduction asexual reproduction

one-celled organisms

For growth

from fertilized egg tomulti-celled organism

For repair & renewal

replace cells that die

from normal wear &

tear or from injury

Why do cells divide?

amoeba


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Getting the right stuff

What is passed on to daughter cells? exact copy of genetic material = DNA

mitosis

organelles, cytoplasm, cell membrane,enzymes

cytokinesis

chromosomes (stained orange)

in kangaroo rat epithelial cell

notice cytoskeleton fibers


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This is the Spider Mite It has 4 chromosomes


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Overview of mitosis

interphase prophase (pro-metaphase)

metaphase anaphase telophase

cytokinesis

I.P.M.A.T.


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Interphase

90% of cell life cycle cell doing its everyday job

produce RNA, synthesize proteins/enzymes

prepares for duplication if triggered


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Interphase

Nucleus well-definedDNA loosely packed in

long chromatin fibers

Prepares for mitosis replicates

chromosome

DNA & proteins

produces proteins &organelles

green = key features


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Synthesis phase of Interphase dividing cell replicates DNA

must separate DNA copies

correctly to 2 daughter cells

S phase: Copying / Replicating DNA


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Copying DNA & packaging it

After DNA duplication, chromatin condenses coiling & folding to make a smaller package

DNA

chromatin

mitotic chromosome


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double-strandedmitotic human

chromosomes


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Mitosis

Dividing cells DNA between2 daughter nuclei

dance of the chromosomes

4 phases prophase

metaphase

anaphase telophase


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Prophase

Chromatin condenses visible chromosomes

chromatids

Centriolesmove to oppositepoles of cell

animal cell

Protein fibers cross cell to formmitotic spindle

microtubules

actin, myosin coordinates movement of

chromosomes

Nucleolus disappears

Nuclear membrane breaks down



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Transition to Metaphase

Prometaphase spindle fibersattach to

centromeres

creating kinetochores

microtubules attach at

kinetochores

connect centromeresto

centrioles

chromosomes begin

moving



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Metaphase

Chromosomes alignalong middle of cell

metaphase plate

meta = middle

spindle fibers coordinate

movement

helps to ensure

chromosomes separateproperly

so each new nucleus

receives only 1 copy of

each chromosome



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Anaphase

Sister chromatids separateatkinetochores

move to opposite poles

pulled at centromeres

pulled by motor proteins

walkingalong microtubules

actin, myosin

increased production ofATP by mitochondria

Poles move farther apart

polar microtubules lengthen



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Separation of chromatids

In anaphase, proteins holding together sisterchromatids are inactivated

separate to become individual chromosomes

2 chromosomes1 chromosome

2 chromatids single-strandeddouble-stranded


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Kinetochores usemotor proteins that

walkchromosome

along attached

microtubule

microtubule

shortens by

dismantling atkinetochore

(chromosome) end

Chromosome movement

k f t


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Telophase

Chromosomes arrive atopposite poles

daughter nuclei form

nucleoli formchromosomes disperse

no longer visible underlight microscope

Spindle fibers disperse Cytokinesisbegins

cell division



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Cytokinesis

Animals constriction belt of

actinmicrofilaments

around equator of cell cleavage furrowforms

splits cell in two

like tightening a draw

string


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AP Biology

Cytokinesis in Animals

(play Cells Alive movies here)

(play Thinkwell movies here)
http://localhost/Users/kfoglia/Kim's%20NEW%20WORK/Division%20Ave%20-%20Levittown/AP%20Bio/MOVIES/Ch12%20The%20Cell%20Cycle/mitosis-CellsAlive.swfhttp://localhost/Users/kfoglia/Kim's%20NEW%20WORK/Division%20Ave%20-%20Levittown/AP%20Bio/MOVIES/Ch12%20The%20Cell%20Cycle/mitosis-CellsAlive.swfhttp://localhost/Users/kfoglia/Kim's%20NEW%20WORK/Division%20Ave%20-%20Levittown/AP%20Bio/MOVIES/Ch12%20The%20Cell%20Cycle/mitosis-CellsAlive.swfhttp://localhost/Users/kfoglia/Kim's%20NEW%20WORK/Division%20Ave%20-%20Levittown/AP%20Bio/MOVIES/Ch12%20The%20Cell%20Cycle/mitosis-CellsAlive.swfhttp://localhost/Users/kfoglia/Kim's%20NEW%20WORK/Division%20Ave%20-%20Levittown/AP%20Bio/MOVIES/Ch12%20The%20Cell%20Cycle/mitosis-CellsAlive.swfhttp://localhost/Users/kfoglia/Kim's%20NEW%20WORK/Division%20Ave%20-%20Levittown/AP%20Bio/MOVIES/Ch12%20The%20Cell%20Cycle/mitosis-CellsAlive.swf


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Mitosis in animal cells


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Cytokinesis in Plants

Plants cell plateforms

vesicles line up at

equator

derived from Golgi

vesicles fuse to form

2 cell membranes

new cell wall laid

down between

membranes

new cell wall fuses

with existing cell wall


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Cytokinesis in plant cell


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Mitosis in plant cell


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onion root tip


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Evolution of

mitosis A possible

progression of

mechanismsintermediate

between binary

fission & mitosis

seen in modernorganisms

protistsdinoflagellates

protists

diatoms

eukaryotes

yeast

eukaryotes

animals

prokaryotes

(bacteria)


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Dinoflagellates

algae red tide

bioluminescence


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Diatoms

microscopic algae marine

freshwater


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Any Questions??


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Ghosts of Lectures Past(storage)


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Control of Cell Cycle


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Kinetochore

Each chromatidhas own kinetochore

proteins

microtubulesattach to

kinetochore

proteins


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nucleosomeDNA

histone

DNA double helixchromosome

rosettes ofchromatin loops

scaffoldprotein

chromatin loop

Chromosome structure


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G2

S G1

M

metaphase

prophase

anaphase

telophase

interphase (G1, S, G2phases)

mitosis (M)

cytokinesis (C)

C

Phases of a dividingcells life

interphase cell grows

replicateschromosomes

produces new organelles, enzymes, membranes

G1, S, G2

mitotic phase cell separates & divides chromosomes mitosis

cell divides cytoplasm & organelles cytokinesis

Cell Division cycle


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Substitute Slides

for Student Print version

(for student note-taking)


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AP Bi l

How did you

get from there

h ?

And now look at you

52ch11mitosis2008 2.original 2

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