1. Homework #3 is due 11/19
Bonus #2 is posted

2. The Cell Cycle
Fig 2.9

3. Mitosis:
A DNA
Perspective

4. Mitosis plays a role in:
Growth and Development
Repair and Turnover of Cells
Reproduction
Asexual

5. start of
mitosis
Fig 2.10

6. A basic look at mitosis
The
Mitotic
Spindle
(micro-
tubules)
Sister
Chromatids

7. Mitosis is tightly regulated: checkpoints

8. Cell division is regulated by both positive and negative signals
Cell division is regulated by both positive and negative signals. Positive signals start the process of cell division. Negative signals inhibit cell division.

9. 2 proteins, Cyclin and Cdk, control entry into mitosis

10. 2 proteins, Cyclin and Cdk, control entry into mitosis.

11. Balance between Longevity and Health
Fig. 3 TRENDS in Ecology and Evolution Vol 21 pg 47

12. Mutations

13. Cancer: Cell Division Gone Wrong

14. Normal Mammalian Cells Have
Contact Inhibition

15. Cancer Cells
Do Not Have
Contact Inhibition

16. Tumors in a Liver
normal
tumors

17. Cancer: is the loss of control over cell division.
Tumors are normal cells that are
dividing inappropriately.
They stop performing their “normal” function, and are dividing repeatedly.

18. A cell becomes cancerous when there are incorrect positive AND negative signals.

19. GO!
STOP!
cancer
similar to Fig 15.36

20. Multiple mutations are required for cancer to occur

23. Normal Cells
Cancer Cells

24. Benign versus Malignant cancer

25. How do these mutations arrise?