Mitosis and
Cytokinesis
Chapter 6.3
The Cell Cycle
The Cell Cycle is a repeating sequence of cellular
growth & division during the life of an organism.
Pre Mitosis- Interphase
Phase of cell division when the cell
copies its DNA grows larger & prepares
to divide.
A cell spends 90% of its lifetime in
Interphase
There are 3 sections of Interphase: G1, S,
and G2
Interphase- G1 Phase
“G1” Phase= First Growth phase
90% of the cells life is spent in the G1 phase\
Carries out routine functions, grows
Some muscle and nerve cells never leave this
stage… what does this mean?
Interphase- “S” phase
“S” phase = Synthesis Phase
DNA is copied
Interphase- G2 Phase
“G2” Phase= 2nd Growth Phase
Microtubules form to prepare for division
Microtubules- Hollow protein fibers that help
pull chromosomes apart
Mitosis!
Mitosis- Process of cell division where the
nucleus divides
Occurs in 4 Steps
Prophase
Metaphase
Anaphase
Telophase
Mitosis Stage 1- Prophase
Nucleus Breaks Down
Spindle Forms to pull microtubules
Chromosomes are visible
Mitosis Stage 2- Metaphase
Chromosomes line up at the equator
Mitosis Stage 3- Anaphase
Chromosomes split
Chromosomes are pulled to opposite sides of
the cell
Mitosis Stage 4- Telophase
The Nucleus reappears
The cell begins to split
Post Mitosis- Cytokinesis
The cell splits into two cells by:
Cleavage Furrow- occurs in animal cells/ cells
without cell walls
Cell Plate Formation- occurs in plant cells/ cells
with cell walls
IMPORTANT !!!!!!!!!
Interphase and Cytokinesis are NOT
considered Mitosis!
MITOSIS is ONLY…
PROPHASE
METAPHASE
ANAPHASE
TELOPHASE