Mitosis
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Mitosis
division of the
nucleus
only occurs in
eukaryotes
has four stages
doesn’t occur in
some cells such
as brain cells
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Four Mitotic Stages
Prophase
Metaphase
Anaphase
Telophase
PMAT!
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Early Prophase
chromatin in nucleus condenses to form
visible chromosomes
spindle forms from fibers in
cytoskeleton or centrioles (animal)
Nucleolus
Cytoplasm
Nuclear Membrane
Chromosomes
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Late Prophase
nuclear membrane & nucleolus are
broken down
chromosomes continue condensing &
are clearly visible
spindle fibers attach to the
centromere of each chromosome
spindle finishes forming between the
poles of the cell
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Late Prophase
Chromosomes
Nucleus & Nucleolus have disintegrated
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Sketch The Spindle
Centromere
Centriole
Spindle fiber
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Metaphase
chromosomes, attached to the spindle
fibers, move to the center of the cell
chromosomes are now lined up at the
equator
Equator of Cell
Pole of
the Cell
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Metaphase
Spindle fibers
Chromosomes at Equator
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Metaphase
spindle
fibers
spindle
fibers
chromosomes
lined at the
equator
chromosomes
lined at the
equator 10
Anaphase
occurs rapidly
chromatids are
pulled apart to
opposite poles
of the cell by
spindle fibers
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Anaphase
chromatids
being
separated
chromatids being
separated
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Telophase
chromatids at opposite poles
spindle disassembles
nuclear envelope forms around
each set of chromatids to make two
nuclei
nucleolus reappears in new nuclei
chromosomes reappear as
chromatin
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chromatids
now back as
chromatin
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Cytokinesis
means division of the cytoplasm
division of cell into two, identical
halves called daughter cells
in plant cells, cell plate forms at
the equator to divide cell
in animal cells, belt of protein
fibers splits the cell
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Cytokinesis
belt of fibers in
animal cell
cell plate in plant
cell
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Daughter Cells of Mitosis
have the same number of
chromosomes as each other & as the
parent cell from which they were
formed
identical to each other, but smaller
than parent cell
must grow in size to become mature
cells (G1 of Interphase)
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Review
of
Mitosis
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Name the Stages
Interphase
Telophase
Prophase
Metaphase
Anaphase
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?
Early, Middle, & Late Prophase
?
?
Metaphase
Late Prophase
Late Anaphase
Anaphase
?
?
Telophase
?
?
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Late Telophase
Uncontrolled Mitosis
if mitosis is not
controlled, unlimited cell
division – this is cancer
masses of cancer cells
cause tumors which
invade surrounding
healthy tissue
not all tumors are
cancerous – some
DON’T invade healthy
tissue
cancer cells
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