3.  Cell division out of control means cancer.  Programmed cell death is a necessary process in living organisms because it makes room for new cells and eliminates “broken” cells.

4. The Cell Cycle Cytokinesis 1 2 3

5.  Print the document “The Cell Cycle and Cancer” from the website. Answer the questions by using the narrated lecture notes to help you!

6. 1. Before a cell divides, the DNA is checked to make sure it has replicated correctly. If DNA does not copy itself correctly, a gene mutation occurs. 2. Chemical Signals tell a cell when to start and stop dividing. 3. Neighboring cells communicate with dividing cells to regulate their growth also.

7. Tumors in LiverTumor in Colon

8. Mutations may be caused by: 1. radiation 2. smoking 3. Pollutants 4. chemicals 5. viruses

10. This prevents cancer cells from communicating with neighboring cells. Cells continue to grow and form tumors. Skin cancer Developing tumor

11. Normal Cell Division 1. DNA is replicated properly. 2. Chemical signals start and stop the cell cycle. 3. Cells communicate with each other so they don’t divide excessively and become overcrowded. Cancer Cells 1. Mutations occur in the DNA when it is replicated. 2. Chemical signals that start and stop the cell cycle are ignored. 3. Cells do not communicate with each other and tumors form.

12. Treating Cancers Cancer treatments include drugs that can stop cancer cells from dividing. Now scientists have for the first time reversed the process of cell division, a breakthrough that could eventually lead to treatments for cancer and other disorders.

13.  The “Check” for this section is handing in the questions “The Cell Cycle and Cancer” that you printed off the website at home.