1. 9-3 CELL CYCLE REGULATION

2. Normal Cell Cycle Proteins called cyclins bind to enzymes called cyclin- dependent kinases (CDK) and signal cell reproduction processes.

3. QUALITY CONTROL CHECKPOINTS  The cell cycle has built-in checkpoints that monitor the cycle and can stop it if something goes wrong.

4.  Cell Growth (G 1 ) Checkpoint – makes the key decision about whether or not the cell will divide  DNA Synthesis (G 2 ) Checkpoint – DNA repair enzymes check DNA replication  Mitosis Checkpoint – Signals the end of mitosis and beginning of G 1 phase. QUALITY CONTROL CHECKPOINTS

5. 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.  Cancer cells spend less time in interphase than normal cells = cancer cells grow and divide unrestrained as long as they are supplied with essential nutrients

6. Certain genes contain information necessary to make proteins that regulate cell growth and division. If these genes are mutated, the protein may not function, and regulation may be disrupted Cancer Causes Some mutations cause cancer by overproducing growth molecules (stepping on the accelerator). Others cause cancer by inactivating the protein checkpoints (removing the brakes).

7. ENVIRONMENTAL INFLUENCES  Tobacco products  Radiation- UV, X-ray  Radon  Viruses  Air pollution  Carcinogen – substances and agents that are known to cause cancer  Food and Drug Administration (FDA) – requires labels and warnings for products that might be carcinogens.

8. Apoptosis  Programmed cell death  Cells going through apoptosis actually shrink and shrivel in a controlled process.

9. Stem Cells  Unspecialized cells that can develop into specialized cells when under the right conditions  Can remain in an organism for many years while undergoing cell division

10. Embryonic Stem Cells  After fertilization, the resulting mass of cells divides repeatedly until there are about 100–150 cells. These cells have not become specialized. "The issue of stem-cell research does not force us to choose between science and ethics, much less between science and religion," the document says. "It presents a choice as to how our society will pursue scientific and medical progress.”

11. Adult Stem Cells  Found in various tissues in the body (brain, bone marrow, blood) 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

12. 1. A 2. B 3. C 4. D FQ 7 Cellular Reproduction Chapter What are the “key and ignition” that start the various activities in the cell cycle? A. chromatin and chromosomes B. cyclin and CDKs C. microtubules and spindle fibers D. protein and ribosomes Section 3 Formative Questions

13. 1. A 2. B 3. C 4. D FQ 8 Cellular Reproduction Chapter Which of these cancer-causing substances or agents is impossible to avoid completely? A. chemicals such as asbestos B. food and drinks that the FDA warns may contain carcinogens C. tobacco and second-hand smoke D. ultraviolet radiation from the Sun Section 3 Formative Questions

14. 1. A 2. B 3. C 4. D FQ 9 Cellular Reproduction Chapter Section 3 Formative Questions What is the term for the programmed death of cells that are damaged beyond repair or have harmful changes in their DNA? A. apoptosis B. carcinogens C. cytokinesis D. mitosis

15. 1. A 2. B 3. C 4. D FQ 10 Cellular Reproduction Chapter Section 3 Formative Questions Which cells are not locked into becoming one particular kind of cell and are capable of developing into specialized tissues? A. apoptotic cells B. cancer cells C. prokaryotic cells D. stem cells

16. 1. A 2. B 3. C 4. D CAQ 3 Cellular Reproduction Chapter What is the role of cyclins in a cell? A.to control the movement of microtubules B.to signal for the cell to divide C.to stimulate the breakdown of the nuclear membrane D.to cause the nucleolus to disappear Chapter Assessment Questions

17. 1. A 2. B STP 4 Cellular Reproduction Chapter Standardized Test Practice Multiple changes in DNA are required to change an abnormal cell into a cancer cell. A. true B. false

18. 1. A 2. B 3. C 4. D STP 5 Cellular Reproduction Chapter Standardized Test Practice Which is not a condition that can result in cancer? A. a failure in the control mechanisms that regulate the cell cycle B. a failure in the repair systems that fix changes or damage to DNA C. a failure of the spindle fibers to move chromosomes during mitosis D. mutations or changes in segments of DNA that control protein production