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Chapter 3: Cell Division
3.3 MITOSIS
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Describe the four stages of the mitotic
cell division
Explain the behavior of the chromosomes
at each stage
Describe briefly the cytokinesis process
Compare the cell division in animal and
plant
State the significance of mitosis.
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MITOSIS
COMPARISON OF CELL
DIVISION
STAGES
CHROMOSOMES
BEHAVIOUR
CYTOKINESIS
PROCESS
PLANT
ANIMAL
SIGNIFICANCE
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CYTOKINESIS
The
division of
cytoplasm
KARYOKINESIS
The division of nucleus
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Consists of 4 phases:
Mitosis
Telophase
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PROPHASE
• Chromatin
become more
tightly coiled &
condensed into
chromosomes
that consist of
2 sister
chromatids.
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PROPHASE
aster
 Mitotic spindle
begins to form
 Centrosomes
move away from
each other to
the opposite
poles
Nucleolus
disappear
Nuclear
envelope
disintegrates
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METAPHASE
Non-kinetochore
microtubule
Kinetochore
microtubule
• Centrosomes are at opposite poles of the cell.
• The sister chromatids arranged themselves
at metaphase plate
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ANAPHASE
• centromeres
split
centromere
• The sister
chromatids
separate and
move apart
towards the
opposite poles
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TELOPHASE
Nucleolus reforms
in each new
nucleus
• Chromatids reach
their respective
poles.
• Chromatids uncoil
and lengthen
 invisible again.
Nuclear
envelope
forms
spindle fibers disintegrate
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Prophase
anaphase
Metaphase
Telophase
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CYTOKINESIS IN ANIMAL CELL
• By cleavage process
• Begin with the appearance of cleavage furrow.
• The furrow is a contractile ring of actin
microfilaments associated with myosin
• The actin microfilaments interact with the myosin Causing ring to contract
• Cleavage furrow deepens until parent cell pinched
into two
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CYTOKINESIS IN PLANT CELL
• By cell plate formation.
• Vesicles- containing cell wall material (cellulose)
derived from golgi apparatus
• Move to the middle of the cell.
• Combine to form cell plate.
• Cell plate enlarges
• fuses with the parent cell plasma membrane
• Make 2 new cell.
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CYTOKINESIS IN ANIMAL CELL
• By cleavage process
• Begin with the appearance of cleavage furrow.
• The furrow is a contractile ring of actin
microfilaments associated with myosin
• The actin microfilaments interact with the myosin Causing ring to contract
• Cleavage furrow deepens until parent cell pinched
into two
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CYTOKINESIS IN PLANT CELL
• By cell plate formation.
• Vesicles- containing cell wall material (cellulose)
derived from golgi apparatus
• Move to the middle of the cell.
• Combine to form cell plate.
• Cell plate enlarges
• fuses with the parent cell plasma membrane
• Make 2 new cell.
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Differences between mitosis in plant
and animal cells
Animal Cells
1. Have centrioles
Plant Cells
1. lack of centrioles.
2. Cytokinesis occurs
2. Cytokinesis occurs
by the constriction of
by the growth of a
microtubules –
cell plate through the
cleavage furrow.
fusion of vesicles.
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Significance of mitosis
1. Genetic stability
•
•
•
Maintain same number of chromosomes as a
parental cell.
Daughter cell are genetically identical to the
parental cell
no variation in genetic information
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2. Growth
• growth in multicellular
organisms.
3. Cell replacement
• Replacement of
damaged cells and
tissues
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4. Regeneration
Some animal are able to regenerate
whole parts of the body
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5. Asexual
reproduction
production of new
individuals of a
species by one
parent organism.
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