1. Why do Cells divide? Growth of tissue Cell repair
When you get a cut, where does the “new skin” come from?

2. Cell Growth Rather than increase in size, cells must divide
To avoid DNA “overload:” Too many chromosomes would result in mutations
Keep exchange of materials through the cell membrane efficient:
How fast water, food, and oxygen are transported through the cell membrane depends on size and volume of the cell

3. Surface Area to Volume Ratio
Cells favor a large Surface Area to volume ratio
The larger the surface area to volume ratio, the easier it is for the cell to transport materials in /out of the cell

4. Size of Cells Are adult and baby cells the same size? Yes!
If mice cells are transplanted into an Elephant will they get bigger?
It depends, but yes!

5. Controls in Cell Growth
Heart & nerve cells rarely divide once they are mature
Skin & digestive tract cells divide constantly to replace shedding or injured cells
This is programmed by the cell cycle which is controlled by DNA

6. Mitosis
Process in which body cells divide to produce two genetically identical (daughter) cells is known as cell division.
It is asexual reproduction
Somatic Cells are all body cells
The only cells that do not do mitosis are sex cells produced in ovaries and testes.

7. Mitosis terms Body cells have a total of 46 chromosomes
They are paired so we have how many pair?
23!
We represent 23 PAIRS as 2n
If we had a total of only 23 it would be just n
We call a total of 23 pairs Diploid, 2n

8. Mitosis -Diagram of Chromosomes WS in packet

9. Mitosis terms-Diagram of key cell terms during mitosis
Chromatin DNA that resembles a ball of yarn
Centrioles -microtubules connect to …
Centrosomes- region of microtubules
Spindle Fibers -connect to chromosomes from Centrioles
Poles -regions on end of cell regions. Spindle fibers connect to them
Metaphase plate -area where chromosomes line up to divide
Cleavage furrow -forms during Telephase. Where cytoplasm divides in the new cells.
Pole

10. The Cell Cycle There are 3 main stages
1. Interphase, the cell prepares for division.
A. 90% of the cells time is spent in this phase.

11. CELL GROWTH PHASE 1. INTERPHASE http://highered. mcgraw-hill
Consists of 3 steps
G1-The cell grows, making additional organelles & cytoplasm
S-DNA replicates
G2-Cell will make anything additional needed for division

12. The cell goes through 4 phases to reproduce a duplicate body cell
MITOSIS is Stage 2 and has 4 PHASES
2. Mitosis
The cell goes through 4 phases to reproduce a duplicate body cell
The phases are:
Prophase
Metaphase
Anaphase
Telophase

13. Phases of Mitosis
Early Prophase Late Prophase

14. Creation of new cytoplasm that divides the cell into 2 new ones.
Stage 3 CYTOKINESIS
Creation of new cytoplasm that divides the cell into 2 new ones.
Plant cell mitosis
Animal cell mitosis

15. Cancer is a form of uncontrolled cell growth
Uncontrolled Cell Growth Teacher’s Domain Cell folder how cancer grows
Cancer is a form of uncontrolled cell growth
The check points that the cell goes through may no longer work
If this occurs, then a tumor may form
It can be non-cancerous which is called benign
Or if it has spread metastasized