2. 9.3 Cell Cycle Regulation Normal Cell Cycle
Chapter 9
Cellular Reproduction
9.3 Cell Cycle Regulation
Normal Cell Cycle
Different chemical signals start and stop the phases of the cell cycle.

3. If a cell is not needed, it dies Apoptosis: Programmed cell death
Chapter 9
Cellular Reproduction
9.3 Cell Cycle Regulation
If a cell is not needed, it dies
Apoptosis: Programmed cell death
Cells going through apoptosis actually shrink and shrivel in a controlled process.
It is normal

4. Examples of Apoptosis:

5. Chapter 9
Cellular Reproduction
9.3 Cell Cycle Regulation
The cell cycle has built-in checkpoints that monitor the cycle and can stop it if something goes wrong.

6. What happens if these check points are not functioning?

7. Abnormal Cell Cycle: Cancer
Chapter 9
Cellular Reproduction
9.3 Cell Cycle Regulation
Abnormal Cell Cycle: Cancer
Cancer is the uncontrolled growth and division of cells.
Cancer cells can kill an organism by crowding out normal
cells, resulting in the loss of tissue function.

8. Causes of Cancer What causes cancer? Cell mutations
Chapter 9
Cellular Reproduction
9.3 Cell Cycle Regulation
Causes of Cancer
What causes cancer?
Cell mutations
Various environmental factors and genetic factors can affect the occurrence of cancer cells.

9. Specialized Cells

10. How do cells become specialized?

11. Chapter 9
Cellular Reproduction
9.3 Cell Cycle Regulation
Stem Cells
Unspecialized cells that can develop into specialized cells when under the right conditions

12. Chapter 9
Cellular Reproduction
9.3 Cell Cycle Regulation
Embryonic Stem Cells
After fertilization, the resulting mass of cells divides repeatedly until there are about –150 cells. These cells have not become specialized.
Scientists are finding ways to make them turn into specific, needed cells

13. Chapter 9
Cellular Reproduction
9.3 Cell Cycle Regulation
Adult Stem Cells
Found in various tissues in the body and might be used to maintain and repair the same kind of tissue
Less controversial because the adult stem cells can be obtained with the consent of their donor