Cell Cycle - Biology - Lecture Slides, Slides for Biology. All India Institute of Medical Sciences

Biology

Description: Cell Cycle, Animal Cells, Main Phases, Interphase and M Phase, Sister Chromatids, Prophase, Prometaphase, Interphase, Chromosomes, Metaphase Plate are some of points from these lecture slides.
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Chapter 5 Gases

1400 nm

Condensed chromosome

2 nm

DNA double helix

700 nm

Condensed chromatin

300 nm fiber (looped

domains)

Extended chromatin

Scaffolding

protein

Fig. 10-4, p. 216

30 nm chromatin fiber

DNA wound

around a

cluster of

histone

molecules

Packed nucleosomes

Stepped Art

Nucleosomes

Histone 10 nm

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The Cell Cycle

• When cells reach a certain size, they usually either stop

growing or divide

cell cycle

• Stages through which a cell passes from one cell division

to the next

• Timing varies (usually 8 to 20 hours in actively growing

plant and animal cells)

• Consists of two main phases, interphase and M phase

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p. 234 docsity.com

Fig. 10-6a, p. 218

INTERPHASE

Chromatin Nucleolus

Nucleus

Nuclear

envelope

Plasma

membrane Centrioles

(a) Cell carries out normal life activities.

Chromosomes become duplicated. docsity.com

Sister Chromatids and Centromeres

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Fig. 10-6 (left), p. 218

Stepped Art

INTERPHASE PROPHASE PROMETAPHASE

Fragments

of nuclear

envelope

Sister chromatids of

duplicated

chromosome

Developing mitotic

spindle

(b) Long fibers of chromatin condense

as compact mitotic chromosomes, each

consisting of two chromatids attached

at their centromeres. Cytoskeleton is

disassembled, and mitotic spindle

forms between centrioles, which have

moved to poles of cell. Nuclear

envelope begins to disassemble.

Kinetochore

Spindle

microtubule

(c) Spindle

microtubules attach to

kinetochores of

chromosomes.

Chromosomes begin

to move toward cell’s

midplane.

Nucleolus

Nucleus

(a) Cell carries out normal

life activities.

Chromosomes become

duplicated.

Chromatin

Centrioles Plasma

membrane

Nuclear

envelope

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Fig. 10-6 (right), p. 219

Stepped Art

METAPHASE ANAPHASE TELOPHASE

Spindle

Centriole

pair at

spindle

pole

Cell’s midplane

(metaphase

plate)

(d ) Chromosomes line

up along cell’s

midplane. Spindle

microtubules attach

each chromosome to

both poles.

Daughter chromosomes

(e) Sister chromatids separate

at their centromeres. One

group of chromosomes moves

toward each pole of cell.

Spindle poles move farther

apart.

Cleavage furrow

Re-forming nuclear envelope

(f) Chromosomes are

grouped at poles.

Chromosomes decondense,

and nuclear envelopes begin

to form. Cytokinesis

produces two daughter cells.

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Fig. 10-9a, p. 221

Metaphase plate (cell’s midplane)

Kinetochore microtubule

(chromosome spindle fiber)

Centrioles

Astral

microtubules

Pericentriolar

material

Polar (non-

kinetochore)

microtubule

Sister

chromatids

(a) One end of each microtubule of this animal cell is associated with one of

the poles. Astral microtubules (green) radiate in all directions, forming the

aster. Kinetochore microtubules (red) connect the kinetochores to the poles,

and polar (nonkinetochore) microtubules (blue) overlap at the midplane. docsity.com

Cohesins

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KEY EXPERIMENT: Chromosome Transport During Anaphase

Fig. 10-10, p. 222 docsity.com

Fig. 12-8b

Kinetochore

Microtubule Tubulin Subunits

Chromosome

Chromosome movement

Motor protein

CONCLUSION

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Cytokinesis in Animal Cells

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Fig. 10-11b, p. 223

Nucleus Cell plate

forming

Vesicles

gather on

cell's

midplane

Small vesicles

fuse, forming

larger vesicles

Eventually

one large

vesicle

exists

New cell walls

(from vesicle

contents)

Plasma

membrane

Cell

wall

Cell plate

forming

New plasma

membranes

(from vesicle

membranes)

(b) Cell plate formation during cytokinesis in a plant cell. The TEM

shows a maple leaf cell (Acer saccharinum) undergoing cytokinesis. docsity.com

Binary Fission

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Key Molecules

• Eukaryotic cells form four major cyclin-Cdk complexes:

• G1-Cdk controls progress from G1 phase to S phase

• G1/S-Cdk commits the cell to DNA replication

• S-Cdk initiates DNA replication

• M-Cdk promotes the events of mitosis

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Key Checkpoints in the Cell Cycle

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Molecular Control of the Cell Cycle

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Cancer Cells

• Density dependent inhibition

• Anchorage dependence

• HeLa cells

• Transformation

• Metastasis

• Benign vs malignant tumor

• 2 cancer treatments.

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Fig. 12-UN5

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