1. Do Now What happens to your body when you get a cut?
Explain in your own words what happens when you receive a cut, and the healing process involved.

2. Chapter 9
Cellular Division

3. Cell Cycle
Varies between 8 minutes and one year
Average hours

4. Size Limitations
Key factor that limits cell growth is ratio of surface area to volume
As the cell grows, its volume increases much more rapidly than the surface area.
Cell can have difficulty supplying nutrients and expelling waste products.
Diffusion over a large distance = slow
Smaller cells are more efficient!
Size also affects the ability of the cell to communicate instructions for cellular functions

5. Cell Cycle All cells start out in Interphase
They then enter cell division, Mitosis & Cytokinesis

6. Interphase A. G1 Phase: First growth phase
The cell is growing, carrying out normal cell functions, and preparing to replicate DNA.
B. S Phase:
S= synthesis
DNA is copied (DNA Replication)
C. G2 Phase:
Second Growth Phase
Proteins needed for cell division are produced
The cell prepares for the division of its nucleus.

7. Mitosis/Cytokinesis Mitosis: Nuclear Division
Cytokinesis: Cell Division

8. Important Vocab. Chromosome-(Duplicated) Chromatid- Chromatin-
Tightly coiled DNA
Chromatid-
Unduplicated Chromosome
Chromatin-
loosely coiled DNA
Centromere-
Center of a chromosome-
where the sister chromatids attach
Centriole-
Organize the microtubules
Attach to the spindle fibers

10. MITOSIS
1. Prophase
2. Metaphase
3. Anaphase
4. Telophase
"PMAT"

11. Prophase Nucleolus disappears Nuclear membrane breaks apart
The cell’s chromatin tightens making chromosomes visible!
Sister chromatids are attached at the centromere.
Spindle apparatus forms and attaches to centromeres of chromosomes.

12. Metaphase
Sister chromatids (duplicted chromosomes) are pulled along the spindle apparatus toward the center of the cell.
They line up in the middle of the cell at metaphase plate.

13. Anaphase
The microtubules (spindle fibers) of the spindle apparatus begin to shorten.
The sister chromatids separate (apart).
The chromosomes move toward the poles of the cell.

14. Telophase The chromosomes arrive at the poles and begin to relax.
Two new nuclear membranes begin to form and the nucleoli reappear.
The spindle apparatus disassembles.
In animal cells, microfilaments constrict, or pinch, the cytoplasm. They create a “cleavage furrow”
In plant cells, a new structure, called a cell plate, forms ( which will eventually become the new cell wall)

15. Cytokinesis Cytoplasm will divide to separate the cells completely.
Forming two new genetically identical daughter cells.

17. Quick Review – Place Cells in Mitosis Order
A B C
D E

18. Let’s Review!

19. Do Now
Label the parts of the cell.
What phases of mitosis?

20. 9.3 Cell Cycle Regulation Normal Cell Cycle:
Different cyclin / CDK (cyclin dependent kinases) combinations signal other activities
These including
DNA replication
Protein synthesis
Nuclear division

21. Quality Control Checkpoints
The cell cycle has built-in checkpoints
These monitor the cycle and can stop it if something goes wrong.
Spindle checkpoints also have been identified in mitosis.
Ex. If no spindle fibers – will stop before cytokinesis

22. Cell Cycle Checkpoints
*If G1 checkpoint shows cell is not ready for DNA replication, it enters G0 phase and will not divide.*

23. When Cell Division Goes Wrong
Begins as a single cell that undergoes “transformation” (process converting a normal cell into a cancer cell)
Immune system fails to destroy cell.
Cell proliferates and forms a tumor.

24. Transformation Transformation is caused by mutations.
Mutations can result from a variety of different “carcinogens” (things that cause cancer)

25. Carcinogens
Tobacco
“Dip” : contains 28 known carcinogens.
Cigarettes

26. Carcinogens UV Light Causes skin cancer (most common type of cancer)
Tanning beds linked to “melanoma”- deadliest type of skin cancer.

27. Carcinogens Pesticides
Overexposure has been known to cause leukemia and lymphoma.

28. Cancer Cells vs. Normal Cells
Cancer cells lack density-dependent inhibition, causing cells to pile up on top of each other
They proceed past checkpoints
They are “immortal”, meaning they can divide an infinite number of times, whereas nomral cells divide only about times before stopping.

29. Tumors Benign tumor Malignant tumor Abnormally growing mass of cells
Can disrupt certain organs, ex: brain, if they get too big
Can be completely removed with surgery
Malignant tumor
Spreads into neighboring tissues
Can metastasize, enter blood and lymph vessels, and spread to other organs and parts of the body

30. Types of Cancer Carcinomas Sarcomas Leukemias and lymphomas
Originates in external or internal “coverings” such as skin or the lining of the intestine
Sarcomas
In tissues that support the body such as bone and muscle
Leukemias and lymphomas
In blood-forming tissues such as bone marrow, spleen, and lymph nodes.

31. Cancer Genetics Multiple changes in DNA are needed to cause cancer
Cancer increase with age
Certain cancers are inherited in certain families (chances to have it)

32. Why haven’t we cured cancer?!

33. Do Now
What is the difference between a benign tumor and a malignant tumor?
What types of cancer did we talk about, and where do they occur?
Do NOT use notes!
Phones on desk

34. Apoptosis Programmed cell death
Cells going through apoptosis actually shrink and shrivel in a controlled process.
Ex. Leaves in Fall
Ex. Webbed Fingers/Toes
DNA Damaged Cells

35. Stem Cells
Unspecialized cells that can develop into specialized cells when under the right conditions

36. What type of stem cells are there?

37. Stem Cells (cont) Embryonic Stem Cells Adult Stem Cells
After fertilization, the resulting mass of cells divides repeatedly until there are about 100–150 cells.
Found in various tissues in the body and might be used to maintain and repair the same kind of tissue
These cells have not become specialized.
Less controversial because the adult stem cells can be obtained with the consent of their donor

38. Stem Cell Controversy

42. As a review…
Draw out all of the phases of mitosis with colored pencils. Use 4 chromosomes