2. Mitosis What is it? Why is it Important? What do I need to know?

3. Why more cells? Populations of single-cell critters Multicellularity? We all start out as a single cell…? The zygote… & become/remain multicellular

4. Binary Fission…Monera

5. Binary Fission..DNA duplicates…why?

6. DNA separates & new cell wall divides cell in two

7. 2 ‘ new ’ cells…identical?

8. Binary Fission

9. quiz What happens to the size of bacteria after binary fission? What has to happen before fission occurs? What benefit(s) do bacteria derive from binary fission (as opposed to sexual reproduction)?

10. Eukaryotic cells?? The nucleus? Nuclear membrane Chromosomes…not chromosome…? All that ‘ stuff ’ in the cytoplasm?

11. Eukaryotic cell cycle Cell is ‘ born ’ Duplicates DNA?? Grows to…size? Prepares to divide Divides=mitosis

14. Control of mitosis:CYCLIN

15. The nuclelus must first divide before the cell can Why? How? How much time of the cell cycle/life can be spent in mitosis?

16. Chromosomes duplicate

21. Kinetochore (centromere)

31. Mitosis produces identical offspring (2N---2N)

32. Why some cells stop mitosis…differentiation Muscle cells… Nerve cells… Critical functions might be disrupted Adaptations to this condition

33. Importance??? Growth Replacement Cancer Regeneration of…

34. Cancer? Unregulated mitosis Benign Malignant/ metastasis How does it begin?

35. Normal cycle controls Internal signals External signals: growth factors fibronectin,etc carcinogens Apoptosis Immune functions And…

36. Cell immortilization!! Hayflick limit?? Hela cells Contact inhibition Increased telomerase activity = immortalization!

37. Immortalization??? If you replaced… Why not??…look at your shoestrings? Telomerase & telomeres & …? Recently… Implications???

38. Mitosis quiz Use two words to describe the importance of mitosis Draw and label the cell cycle…include G1, S, G2, M and cytokinesis…what happens at each stage? Why might telomerase be important? What disease is associated with mitosis? Are all organisms limited to 50 mitotic divisions?

39. Name stage of mitosis

47. These are bacteria Watch the clip What kind of reproduction is shown here? What advantage does this confer on the organism?