2. Cell Division
● Cell Theory…..All cells come from
preexisting cells: Parents and daughters
● Prokaryote vs. Eukaryote
● What are the major differences for these
cells?
3. Binary Fission
A type of cell reproduction for prokaryotic cells
DNA is copied and two identical cells are
formed.
Type of asexual reproduction
7. Cell Cycle
● A repeating set of
events in the life of a
cell
● Cell division is one
phase of this cycle
● Interphase is the time
between these divisions
8. Interphase
Three parts:
1. Cell growth (G1
)
2. DNA is copied (S)*** Important for division!
3. Growth and preparation for cell division (G2
)
* Special G0
phase: nervous system cells: when
one reaches maturity these cells seldom divide
again. Brain damage.
10. Prophase
● When DNA is formed into chromosomes -
two identical chromatids connected by the
centromere
● Nucleolus and nuclear membranes start to
disappear
● Centrosomes appear and special
microtubules called spindle fibers form.
11. Prophase
● In animal cells, centromeres
will also have centrioles,
which look like barrels
● The spindle fibers radiating
from the centrioles will
eventually attach to the
centromere on the
chromosome
15. Control
● Through a series of checkpoints, specialized
proteins will decide whether a cell should
divide or not
● There are three check points, one at G1, G2,
and at Mitosis
16. Mitosis Checkpoint
If the cell passes through this checkpoint,
proteins will signal for the cell to enter back
into G1 phase
17. Loss of Control
What happens when the cell losses this control?
What happens when a cell that is not healthy
undergoes cell division?
How is this control lost?
