1. The Cell Cycle

2. DNA wraps itself around proteins DNA + protein is called Chromatin As chromatin condenses… DNA has a Double helix shape visible under a light microscope. it becomes This is a naked strand of DNA Visible, compact chromatin makes up a Chromosome

3. This is another look at how DNA is packaged. Naked DNA Chromatin Supercoils Chromosome

4. Centrioles Centrosome Centromeres The three C’s that might confuse you.

5. Interphase

6. Replicates Centrosomes DNA Chromatin forms supercoils (“S” stage) Cell membrane Cytoplasm The Cell in Interphase (“G 2 ” stage) Nucleolus Nucleus “G 1 ” stage

7. Mitotic Phase

8. MITOSIS

9. The Cell in Early Prophase Chromatin condenses Chromosomes become visible Nucleolus disappears

10. Nuclear envelope breaks down Centrosomes move apart Spindle fibers form The Cell in Late Prophase

11. METAPHASE Chromosomes align in middle of the cell Spindle fibers attach to centromeres

12. METAPHASE Under the microscope, chromosomes may appear flat. In the cell however, chromosomes have a three-dimensional arrangement.

13. ANAPHASE “Free” spindle fibers lengthen; cell elongates Sister Chromatids separate and move apart Spindle microtubules disintegrate behind chromatids

14. TELOPHASE Daughter chromosomes reach centrosomes

15. CYTOKINESIS Cell divides into two identical daughter cells Nuclear membrane reforms TELOPHASE Mitotic spindle disappears Nucleoli reappear

16. CYTOKINESIS INTERPHASE New daughter cells

17. Mitosis Animated Click through the next 30 slides to see a rough animation of the cell cycle.

18. The Cell in Interphase 1

19. Interphase 2

20. 3

21. 4

22. 5

23. 6

24. 7

25. Prophase 8

26. 9

27. 10

28. Prophase 11

29. Metaphase 12

30. Metaphase 13

31. Metaphase 14

32. Anaphase 15

33. Anaphase 16

34. Anaphase 17

35. Anaphase 18

36. Telophase 19

37. Telophase 20

38. Telophase Cytokinesis 21

39. Telophase Cytokinesis 22

40. Telophase Cytokinesis 23

41. Telophase Cytokinesis 24

42. Telophase Cytokinesis 25

43. Daughter Cells 26

44. Daughter Cells 27

45. Daughter cells 28

46. Interphase 29

47. Interphase 30

48. MITOTIC EVENTS PRACTICE IDENTIFY THE MITOTIC EVENTS IN THE SLIDES WHICH FOLLOW

49. What mitotic event is shown? Answer: Anaphase

50. What mitotic event is shown? Answer: Prophase

51. What mitotic event is shown? Answer: Telophase

52. What mitotic event is shown? Answer: Metaphase

53. Cell Cycle Organizer Cell Cycle Interphase Mitotic Phase Mitosis Cytokinesis Prophase G1G1 S G2G2 Telophase Metaphase Anaphase