Download Powerpoint Presentation: Cell Division

CELL DIVISION
© 2006 Mesoblast Limited www.mesoblast.com
© 2007 Paul Billiet ODWS
Cell division is a fundamental process
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All cells come from pre-existing cells
It is necessary to replace worn out cells in
multicellular organisms
It is required for growth in multicellular organisms
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An increase in size will require an increase in surface area
to volume ration
Cell division subdivides the cytoplasm into small units
(cells) surrounded by plasma membranes
It is necessary for reproduction in unicellular or
multicellular organisms
© 2007 Paul Billiet ODWS
Cell division and reproduction
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It is necessary for
reproduction in
unicellular or
multicellular
organisms
Microbus
© Microscope-Microscope.org
© 2007 Paul Billiet ODWS
Prokaryotes
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Prokaryotes have
no nucleus
They have a single
circular chromosome
Prokaryotes simply
divide their cells in
two by binary
fission
http://instruct1.cit.cornell.edu/
© 2007 Paul Billiet ODWS
Eukaryotes
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Eukaryotes must divide their nucleus (and
other organelles such as mitochondria) in
preparation for cell division (mitosis or
meiosis)
Before the nucleus divides the genetic
material replicates (duplicates)
© 2007 Paul Billiet ODWS
Mitosis
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Mitotic division
results in genetically
identical eukaryotic
cells (a clone)
Mitosis is the basis of
asexual
reproduction
© 2007 Paul Billiet ODWS
© Tyler Junior College, (no
commercial use allowed - contact
[email protected] for permission to use)
Meiosis
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Meiosis results in a halving of the
chromosome number in preparation for
fertilisation
Meiosis shuffles genes in new combinations
Meiosis results in genetically different cells
Meiosis and fertilisation are the basis of
sexual reproduction
© 2007 Paul Billiet ODWS
COMPARING MITOSIS AND
MEIOSIS
© 2007 Paul Billiet ODWS
COMPARING MITOSIS AND
MEIOSIS
© 2007 Paul Billiet ODWS