1. Review of what we’ve learned… https://www.youtube.com/watch?v=JcZQkmooyPk https://www.youtube.com/watch?v=JcZQkmooyPk (c) McGraw Hill Ryerson 2007

2. Finishing 5.1: Problems in the Cell Cycle (c) McGraw Hill Ryerson 2007

3. How Cells Try to Prevent Problems There are “checkpoints” in the cell cycle to help prevent problems. The cell cycle will not continue unless conditions are met at these checkpoints. Cells will NOT divide by mitosis if: the cell is short of nutrients the DNA has not been replicated the DNA is damaged http://outreach.mcb.harvard.edu/animations/checkpoints.swf See pages 159 - 161

4. (c) McGraw Hill Ryerson 2007 CANCER: A Cell Cycle Problem What is cancer? Cancer = uncontrolled cell division The cell checkpoints aren’t working Why don’t the checkpoints work? Mutations: there are mutations in checkpoint-related genes What can happen when there is out-of-control cell division? a tumour may form – this is just a clump of cells dividing uncontrollably blood vessels may grow into tumours which supply cancer cells with nutrients cells from tumours may break away to other areas of the body through the blood vessels – this is how cancer spreads See pages 159 - 161

5. (c) McGraw Hill Ryerson 2007 CANCER: A Cell Cycle Problem A little more detail about cancer cells Cancer cells have large, abnormal nuclei Cancer cells are not specialized, so they serve no function Do you know anyone who has cancer or had cancer? Who? What kind? What happened? What do you still wonder about cancer? Come up with at least 5 questions. See pages 159 - 161

6. (c) McGraw Hill Ryerson 2007 CANCER: A Cell Cycle Problem As the following videos are played, write down 10 things you learned that you didn’t know before. https://www.youtube.com/watch?v=UopUxkeC4Ls https://www.youtube.com/watch?v=keIs5aIAG8o https://www.youtube.com/watch?v=LEpTTolebqo See pages 159 - 161 Take the Section 5.1 Quiz Take the Section 5.1 Quiz