Transcript Mitosis - ustarbiology

Mitosis
Chapter 10
Pages 240-253
Cell Growth or Cell Division
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Personal growth—when you grow, what
happens to your cells? Grow or Divide?
The larger a cell becomes, the more
demands the cell places on its DNA. In
addition, the cell has more trouble moving
enough nutrients and wastes across the cell
membrane.
Cell must divide to accomplish necessary
tasks.
Mitosis Video
Cell Division
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Cell division—process by which a cell
divides into two “daughter” cells
Before cell division occurs, the cell copies
all of its DNA.
Two stages to cell
division
1.
2.
Mitosis
Cytokinesis
Chromosomes
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Each chromosome is copied before cell
division, so each chromosome consists of 2
“sister” chromatids
During cell division sister chromatids
separate
Centromeres—hold sister chromatids
together
Human—46 chromosomes
Cell Cycle
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Cell cycle—during the cell
cycle, a cell grows, prepares
for division and divides to form
two daughter cells, each of
which then begins the cycle again.
Interphase—time between cell divisions
It is a period of cell growth
Mitosis—four phases
Prophase—longest phase of
mitosis
1.
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2.
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Chromosomes condense
Nuclear envelope dissolves
Metaphase—chromosomes line up across
the middle
Microtubules connect to the centromeres
Mitosis cont.
3. Anaphase—centromeres split
allowing the sister chromatids to
separate and become individual
chromosomes
4. Telophase—chromosomes disperse
–
Nuclear envelope reforms
around each cluster of
chromosomes
Cytokinesis
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Cytokinesis—division of the cytoplasm
Animal cells—the cell membrane is drawn
inward until the cytoplasm is pinched in two
Plant cells—cell plate forms midway between
divided nuclei
Video
Regulations to the Cell Cycle
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Proteins (cyclins) regulate timing
Growth factors—stimulate growth and
division of cells
Uncontrolled cell growth
–
Cancer/tumors—do not respond to
signals from
proteins
Picture Credits
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http://www.gcarlson.com/images/new_cell_division.jpg
http://www.karlloren.com/biopsy/images/mitosis.jpg
http://www.learner.org/channel/courses/biology/images/archive/fullsize/1940_fs.jpg
http://www.galaxynet.com/~corvid/cel/images/celi_cell_cycle.gif
http://www.phschool.com/science/biology_place/labbench/lab3/images/prophase.gif
http://www.uic.edu/classes/bios/bios100/labs/metaphase.jpg
http://faculty.southwest.tn.edu/jiwilliams/Anaphase.gif
http://www.agintheclass.com/CellBiology/images/CellBio/Lesson2/telophase.gif
http://www.indigo.com/software/gphpcd/em21.jpg
http://www.bio.txstate.edu/~dlemke/botany/1410lab/lab_exercises/lab3/cell_cycle/cytokines
is.jpg
http://www.genomenewsnetwork.org/gnn_images/news_content/11_03/ovarian_cancer/ova
rian-cancer-cell-color.jpg
http://www.txtwriter.com/backgrounders/Cancer/figure1.jpg
http://botit.botany.wisc.edu/images/130/Mitosis/Allium_Root_Prep._Slides/Prophase.low.jp
g
http://botit.botany.wisc.edu/images/130/Mitosis/Allium_Root_Prep._Slides/telophase_cytoki
nesis.low.jpg
http://www.lima.ohio-state.edu/biology/images/metaphase.jpg
http://www.freethought-forum.com/images/anatomy4/mitosis.gif