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

3. What is Mitosis? MITOSIS: division of the nucleus into two identical daughter cells http://fairmanstudios.com/als.htm

4. Why is mitosis important? Eukaryotes use cell division to create new cells Growth, Maintenance and Repair of body cells Asexual cell division

5. What makes up the cell cycle?

6. MITOSIS is about organizing and distributing CHROMOSOMES ≠Chromosome made of a DNA and protein complex: chromatin Following DNA replication, a chromosome contains two sister chromatids attached by a centromere Sister Chromatids Centromere Chromosome

7. What happens in INTERPHASE? Cells are in interphase 90% of the time G1 = Gap 1 (cell growth) S =chromosome synthesis (duplication) G2 = Gap 2 (cell growth) M = Mitosis

8. INTERPHASE: nuclear envelope clearly visible chromatin, NO chromosomes, yet nucleolus (if any) still visible

9. PROPHASE

12. chromosomes become visible nuclear envelope disappears nucleolus disappears

13. PROPHASE Centrioles migrate & form spindle. Centrioles

16. Kinetochore (centromere)

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

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

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

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

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

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

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

33. 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?

34. Name stage of mitosis

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