From Interphase to mitosis to cytokinesis, what are the basics of cell division and the cell's life cycle?

1. Skin cancer - the abnormal
growth of skin cells - most
often develops on skin
exposed to the sun.
 1. Growth –from a baby to an adult – you need more cells.
 2. Repair – if you get a cut – you need more cells to fill in the
cut.
 3. Replacement – when cells die – they need to be replaced.
 Fun fact: Skin cancer is the abnormal growth of cells – they
don’t know when to stop making more – this produces a tumor.

2. The cell life cycle
consists of:
 Interphase -normal activities for the cell
 Mitosis (5 steps):
1.Prophase – nucleus dissapears
2. Metaphase – chromosomes line up
3. Anaphase – chromosomes separate
4. Telophase – nuclei form
 Cytokinesis - cell splits in two
 Back to Interphase – normal activities for the cell

3. • G1 phase: Cell grows in size
• S phase: Chromosomes are
copied - the number doubles.
(In the microscope, DNA
appears as threadlike
spaghetti called chromatin).
• G2 phase: Cell double checks
that DNA has been copied and
cell has enough organelles for
the upcoming split
Draw this

4. • Nucleus starts to
disappear.
• Chromatin coils up into
chromosomes.
• Centrioles (or poles)
appear and begin to move
to opposite end
of the cell.
• Spindle fibers form
between the poles.
centriole
Draw this

5. • Chromosomes are
dragged to middle of
cell along the
metaphase plate.
Centriole
Don’t draw this

6. • Chromatids (or pairs
of homologous
chromosomes)
separate and begin to
move to opposite ends
of the cell.
Sister
chromatids
Draw this

7. • Two new nuclei form.
• Chromosomes unwind into
chromatin (threads instead
of bundles).
• Mitosis ends.
Draw this

8. • Cell membrane
moves inward
to create two
daughter cells
– each with its
own nucleus.
Draw this

9. • The cell wall makes plant cells rigid, so they can’t move inward
and separate like animal cells can.
• Vesicles filled with cell wall parts are towed to the middle of the
cell.
• They fuse together, forming a “cell plate.”
• The cell plate becomes the new cell wall.