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CELL DIVISION
Mitosis
WHAT IS MITOSIS?
Part of eukaryotic cell division during which the
cell nucleus divides.
Results in the formation of 2 identical daughter
cells.
Mitosis is completed in 4 distinct steps.
THE CELL CYCLE
Mitosis takes up very little
of the life time of a cell.
90% of the time our cells
are in between cell
divisions.
We call this in between
time INTERPHASE.
INTERPHASE
 There are 3 phases of interphase in which the cell is carrying out
different functions.
• G1: First phase of interphase in which a cell does most
of its growing. They increase in size and synthesize new
proteins and organelles.
• S: The second phase of interphase. Chromosomes are
replicated and the synthesis of DNA molecules takes
place.
• G2: Third phase of interphase. The cell prepares itself
for mitosis.
PHASES OF MITOSIS
 Biologists divide the events of mitosis into four phases:
Prophase, metaphase, anaphase, and telophase.
 IPMAT. IPMAT?
 An easy device to help remember the steps of the cell cycle
in the correct order. Interphase, Prophase, Metaphase,
Anaphase, Telophase.
PROPHASE
First and longest stage of
mitosis, during which the
chromosomes become
visible and the centrioles
separate and take up
positions of the opposite
sides of the nucleus.
PROPHASE (CONT.)
The nuclear membrane and
nucleolus disappear during
prophase. The spindle
fibers begin to form and
attach themselves to the
centromeres of the
chromosomes
METAPHASE
Second phase of mitosis, during
which the chromosomes line up
across the center of the cell.
ANAPHASE
Third phase of
mitosis, during which
the chromosome
pairs separate and
move toward
opposite poles.
TELOPHASE
Fourth and final phase of
mitosis, during which the
chromosomes begin to
unravel back into
chromatin.
The nuclear membrane
and nucleolus reform.
CYTOKINESIS
Cytokinesis, while technically not a
part of mitosis, results in the physical
splitting of the cytoplasm.
The sides of the cell membrance
pinch inwards creating a cleavage
furrow.
Afterwards, the two new daughter
cells will enter the G1 phase of
interphase.
PUTTING IT TOGETHER
 Mitosis in action