Download The Cell Cycle

The Cell Cycle
Ms. Mele Grade 8
Life Science
Watson video
Three stages of the cell cycle
 Interphase
 Mitosis
 Cytokinesis
Rat epithelial cell
Stage 1: Interphase
 Cell
grows to its mature size
 Makes a copy of its DNA
 Prepares to divide into two
cells.
Stage 2: Mitosiswhen the cell’s nucleus divides into
two new nuclei.
 Prophase
 Metaphase
 Anaphase
 Telophase
Prophase
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The chromatin condenses to form
rodlike chromosomes.
Each chromosome has 2 rods
The identical rods are called
chromatids.
Spindle fibers form a bridge between
the ends of the cell.
The nuclear membrane breaks down.
duplicated
chromosome
chromatin
Metaphase
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The chromosomes line up across the
center of the cell
Each chromosome attaches to a spindle
fiber at its centromere, which holds the
chromatids.
Chromatids are the identical rod of a
chromosome.
Anaphase
The centromeres split
 Two chromatids separate
 One chromatid moves along the
spindle fiber to one end of the cell
 The other chromatid moves to the
opposite end
 The cell becomes stretched out as
the opposite ends pull apart
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Telophase
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The chromosomes begin to stretch out
and lose their rodlike appearance
This occurs in the two regions at the ends
of the cell
A new nuclear membrane forms around
each region of chromosomes
ANIMAL CELL CENTROSOME:
Cytokinesis
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The cell membrane pinches in around the
middle of the cell
Each daughter cell ends up with the same
number of identical chromosomes
Length of the Cell Cycle
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Depends on the type of cell
A human liver cell completes the cycle in
22 hours
Each cycle also varies from cell to cell
Human brain cells never divide, they stay
at interphase