AP Biology 2011-2012

Biology is the only subject

in which multiplication is the

same thing as division…

AP Biology 2007-2008

The Cell Cycle:Cell Growth, Cell Division

AP Biology

Where it all began…

You started as a cell smaller than

a period at the end of a sentence…

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And now look at you…

How did you get from there to here?

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How do little elephants grow up to be BIG elephants?

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Going from egg to baby….

the original fertilized egg has to divide…

and divide…

and divide…

Getting from there to here…

http://www.youtube.com/watch?v=VsyBzIeF1zI&feature=mfu_in_order&list=UL

http://www.youtube.com/watch?v=pgahp5_naVw&feature=mfu_in_order&list=UL

http://www.youtube.com/watch?v=vXNaTRs83hE

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For reproduction

asexual reproduction

one-celled organisms

For growth

from fertilized egg to

multi-celled organism

For repair & renewal

replace cells that die

from normal wear &

tear or from injury

Why do cells divide?

amoeba

http://www.youtube.com/watch?v=rgLJrvoX_qo

http://www.youtube.com/watch?v=UgT5rUQ9EmQ

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Making new cells

Nucleus

chromosomes

DNA

Cytoskeleton

centrioles

in animals

microtubule

spindle fibersHow is the cytoskeleton involved in reproduction?

AP Biology

nuclearpores

nuclearpore

nuclear envelope

nucleolus

histone protein

chromosome

DNA

Function

protects DNA

Structure

nuclear envelope

double membrane

membrane fused in spots to create pores

allows large macromolecules to pass through

Nucleus

What kind of molecules need to

pass through?

http://www.youtube.com/watch?v=gbSIBhFwQ4s&feature=related

AP Biologyhttp://www.youtube.com/watch?v=yqESR7E4b_8&feature=fvst

AP Biology

Cytoskeleton Function

structural support maintains shape of cell

provides anchorage for organelles

protein fibers

microfilaments, intermediate filaments, microtubules

motility cell locomotion

cilia, flagella, etc.

regulation

organizes structures

& activities of cell

AP Biology

Microtubules, Microfilaments, and Intermediate Filaments

http://www.youtube.com/watch?v=x2ElL2VVKi8&feature=related

Summarize in a table.

Your table should be in your notebook already.

Review it.

AP Biology

Cytoskeleton

Intermediate Filaments: interwoven, rope-strands

built from a family of proteins

called keratins.

Function: Strength, maintain shape, fix organelle location.

Microtubules: tubes composed of spiraling tubulin

in two-part subunits.Function: shape & support

chromosome movement (centriole, spindle fibers)

movement of organelles (serve as tracks)

movement of cellular appendages (cilia, flagella)

“highways” along which the organelles travel Microtubule roads are dynamic. Assembled at one end

while being disassembled at the other.

Microfilaments: twisted double chain of actin subunits

Function: to bear tension,

resists pulling tensions within cell

(prevents cell from collapsing)

motility (cell movement) and shape,

and simply holding the cell together.

http://www.studiodaily.com/main/searchlist/6850.html

AP Biology

Cytoskeleton

Intermediate filaments

AP Biology

Centrioles Cell division

in animal cells, pair of centriolesorganize microtubules spindle fibers

guide chromosomes in mitosis

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End of the Tour

Yes. All that should have been review!

AP Biology

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 cytoskeletal fibers

http://www.youtube.com/watch?v=VGV3fv-uZYI

AP Biology

Overview of mitosis

interphase (pro-metaphase)

metaphase anaphase telophase

cytokinesis

IPMAThttp://www.cellsalive.com/mitosis.htm

prophase

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Overview of mitosis

interphase prophase (pro-metaphase)

metaphase anaphase telophase

cytokinesis

I.P.M.A.T.

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Animal Mitosis -- ReviewInterphase Prophase

Metaphase Anaphase

Telophase Interphase

AP Biology

Plant Mitosis -- ReviewInterphase Prophase

Metaphase Anaphase

Telophase Interphase

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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

I’m working here!

Time to divide& multiply!

AP Biology

Cell cycle

M

Mitosis

G1

Gap 1

G0

Resting

G2

Gap 2

S

Synthesis

Cell has a “life cycle”

cell is formed from

a mitotic division

cell grows & matures

to divide again

cell grows & matures

to never divide again

G1, S, G2, M G1G0

epithelial cells,

blood cells,

stem cells

liver cells

brain / nerve cells

muscle cells

AP Biology

Interphase Divided into 3 phases:

____ = 1st Gap

cell doing its “everyday job”

cell grows

____ = DNA Synthesis

copies chromosomes

____ = 2nd Gap

prepares for division

cell grows (more)

produces organelles,proteins, membranes

G0

AP Biology

Interphase Divided into 3 phases:

G1 = 1st Gap (Growth)

cell doing its “everyday job”

cell grows

S = DNA Synthesis

copies chromosomes

G2 = 2nd Gap (Growth)

prepares for division

cell grows (more)

produces organelles,proteins, membranes

G0

AP Biology

Interphase Nucleus well-defined

DNA loosely packed in long chromatin fibers

Prepares for mitosis

replicates chromosome

DNA & proteins

produces proteins & organelles

green = key features

AP Biology

Synthesis phase of Interphase

dividing cell replicates DNA

must separate DNA copies

correctly to 2 daughter cells

human cell duplicates ~3 meters DNA

each daughter cell gets complete

identical copy

error rate = ~1 per 100 million bases

3 billion base pairs in mammalian

genome

~30 errors per cell cycle

mutations (to somatic (body) cells)

S phase: Copying / Replicating DNA

http://www.youtube.com/watch?v=teV62zrm2P0

http://www.youtube.com/watch?v=AGUuX4PGlCc&feature=related0

AP Biology

Organizing DNA DNA is organized in

chromosomes double helix DNA molecule

wrapped around histone proteins like thread on spools

DNA-protein complex =chromatin organized into long thin fiber

condensed further during mitosis

DNA

histones

chromatin

duplicated mitotic chromosome

ACTGGTCAGGCAATGTC

double stranded chromosome

http://www.youtube.com/watch?v=gbSIBhFwQ4s&feature=related

AP Biology

Copying DNA & packaging it… After DNA duplication, chromatin condenses

coiling & folding to make a smaller package

DNA

chromatin

mitotic chromosome

AP Biology

double-strandedmitotic humanchromosomes

AP Biology

Mitotic Chromosome Duplicated chromosome

2 ___________________

narrow at ____________

contain identical

copies of original DNAhomologous

chromosomeshomologous

chromosomes

sister chromatidshomologous = “same information”

single-strandeddouble-stranded

AP Biology

Mitotic Chromosome Duplicated chromosome

2 sister chromatids

narrow at centromeres

contain identical

copies of original DNAhomologous

chromosomeshomologous

chromosomes

sister chromatidshomologous = “same information”

single-strandeddouble-stranded

AP Biology

Mitosis

Dividing cell’s DNA between

2 daughter nuclei

“dance of the chromosomes”

4 phases

_____________

_____________

_____________

_____________

AP Biology

Mitosis Divides cell’s DNA between

2 daughter nuclei

4 phases

prophase

metaphase

anaphase

telophase

PMATI

AP Biology

Prophase Chromatin condenses

visible chromosomes chromatids

Centrioles move to opposite poles of cell

animal cell

Protein fibers cross cell to form mitotic spindle

microtubules

actin, myosin

coordinates movement of chromosomes

Nucleolus disappears

Nuclear membrane breaks down

green = key features

AP Biology

Transition to Metaphase Prometaphase

spindle fibers attach to

centromeres

creating kinetochores

microtubules attach at

kinetochores

connect centromeres to

centrioles

chromosomes begin

moving

green = key features

AP Biology

Metaphase Chromosomes align

along middle of cell

metaphase plate

meta = middle

spindle fibers coordinate

movement

helps to ensure

chromosomes separate

properly

so each new nucleus

receives only 1 copy of

each chromosome

green = key features

What is lining up in the center?

AP Biology

AP Biology

Anaphase Sister chromatids separate at

kinetochores

move to opposite poles

pulled at centromeres

pulled by motor proteins

“walking”along microtubules

actin, myosin

increased production of

ATP by mitochondria

Poles move farther apart

polar microtubules lengthen

green = key features

AP Biology

Separation of chromatids

In anaphase, proteins holding together sister

chromatids are inactivated

separate to become individual chromosomes

1 chromosome

2 chromatids

double-stranded

1 chromosome

2 chromatids

double-stranded

a. Label the sister chromatids.

b. Label the single stranded chromosomes.

c. Label the kinetochores.

AP Biology

Separation of chromatids

In anaphase, proteins holding together sister

chromatids are inactivated

separate to become individual chromosomes

2 chromosomes1 chromosome

2 chromatidssingle-stranded

double-stranded

AP Biology

Kinetochores use

motor proteins that

“walk” chromosome

along attached

microtubule

microtubule

shortens by

dismantling at

kinetochore

(chromosome) end

Chromosome movement

http://www.youtube.com/watch?v=kVMb4Js99tA

This video is for meiosis:

AP Biology

Telophase Chromosomes arrive at

opposite poles

daughter nuclei form

nucleoli form

chromosomes disperse

no longer visible under light microscope

Spindle fibers disperse

Cytokinesis begins

cell division

green = key features

AP Biology

Cytokinesis

Animals

constriction belt of

actin microfilaments

around equator of cell

cleavage furrow forms

splits cell in two

like tightening a draw

string

AP Biology

Cytokinesis in Animals

http://www.cellsalive.com/mitosis.htm

http://highered.mcgraw-

hill.com/sites/0072495855/student_view0/chapter2/ani

mation__mitosis_and_cytokinesis.html

http://www.biology.arizona.edu/cell_bio/tutorials/cell_cy

cle/MitosisFlash.html

AP Biology

Mitosis in whitefish blastula

AP Biology

Mitosis in animal cells

AP Biology

Cytokinesis in Plants Plants

cell plate forms

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

AP Biology

Cytokinesis in plant cell

AP Biology

Mitosis in plant cell

AP Biology

onion root tip

AP Biology

Origin of replication

chromosome:double-stranded

DNAreplication

of DNA

elongation of cell

cell pinches in two

ring of proteins

Evolution of mitosis

Mitosis in

eukaryotes

likely evolved from

binary fission in

bacteria

single circular

chromosome

no membrane-

bound organelles

http://www.youtube.com/watch?v=2_K7qBPaQrw&feature=related

AP Biology

Evolution of mitosis

A possible

progression of

mechanisms

intermediate

between binary

fission & mitosis

seen in modern

organisms

protists

dinoflagellates

protists

diatoms

eukaryotes

yeast

eukaryotes

animals

prokaryotes

(bacteria)

AP Biology

Dinoflagellates

algae

“red tide”

bioluminescence

AP Biology

Diatoms

microscopic algae

marine

freshwater

AP Biology 2011-2012

Additional slides

that might be of interest.

AP Biology

Control of Cell Cycle

AP Biology

nucleosomeDNA

histone

DNA double helixchromosome

rosettes ofchromatin loops

scaffoldprotein

chromatin loop

Chromosome structure