1. Cell Division and Cancer

2. CB 5.25 Genes are the parts of DNA that contain information. Protein

3. For life to exist, the information (genes) must be passed on. {Mitosis: producing more cells} {Meiosis: producing gametes} CB 13.5

4. Mitosis

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

6. The Cell Cycle [DNA Replication] CB 12.5

7. Complementary base pairs suggest how DNA replication may occur CB 16.9

8. DNA replication: each strand serves as a template for making a complementary copy O.R. Origin of Replication CB 16.12b

9. O.R. DNA replication: each strand serves as a template for making a complementary copy CB 16.12b

10. The two strands of DNA are unwound. DNA replication: each strand serves as a template for making a complementary copy CB 16.12b

11. The DNA is copied by DNA polymerase (a protein). DNA replication: each strand serves as a template for making a complementary copy CB 16.12b

12. More unwinding, more copying DNA replication: each strand serves as a template for making a complementary copy CB 16.12b

13. The DNA has now been copied. There are now two double-stranded DNAs DNA replication: each strand serves as a template for making a complementary copy CB 16.12b

14. Most DNA has multiple origins of replication CB 16.12b

15. DNA replication: each strand serves as a template for producing a complementary copy CB 5.28

16. Sometimes errors are made.

17. Luckily, errors can be repaired. Error

18. DNA Repair CB 16.18 Damage or replication error Mismatch removed by enzymes DNA replaced Repair complete

20. Is recognized as NEW and mismatches are repaired

21. Not all errors get repaired. These are mutations.

22. 3,000,000,000 (3 billion) base pairs/human cell with 1 error/1 billion base pairs not repaired = (average) ~6 errors each time DNA is replicated Errors are made during DNA replication

23. Only mutations in gametes will be passed on.

24. Mutations can be lethal, or can lead to cancer.

25. Cancer: Cell Division Gone Wrong

26. 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.

27. Tumors in a Liver normal tumors

28. Multiple mutations are required for a single cell to become cancerous. CB 18.22

29. How can mutations be minimized?

30. Telomeres are non-gene DNA at the ends of DNA strands.

31. Telomeres are shortened during DNA replication.

32. Telomeres are non-gene DNA at the ends of DNA strands. Telomeres are shortened during DNA replication, and also by DNA damage.

33. Telomeres are non-gene DNA at the ends of DNA strands. Short telomeres will cause cells to stop replicating or cell death. The critical size is unknown.

34. Human Life Cycle high levels of telomerase very little telomerase

35. Why not produce telomerase all of the time? high levels of telomerase very little telomerase

36. Telomeres are non-gene DNA at the ends of DNA strands. Telomeres are shortened during DNA replication, and by DNA damage. Short telomeres will cause cell senescence or cell death. Telomere size is an indirect measure of mutations.

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

38. Do telomere dynamics link lifestyle and lifespan? Pat Monaghan and Mark F. Haussmann TRENDS in Ecology and Evolution Vol 21 pg 47

39. Telomere length varies in different parts of adults: telomeres - mitosis stomach & blood cells....short- often

40. muscle & brain……….long- rare

41. Telomere length varies in different parts of adults: telomeres - mitosis stomach & blood cells....short- often muscle & brain……….long- rare liver & kidney……..short- rare

42. Telomere length varies in different parts of adults: telomeres - mitosis stomach & blood cells....short- often muscle & brain……….long- rare liver & kidney……..short- rare gametes……long

43. Zebra finch Telomere length in red blood cells of different birds Fig. 1 TRENDS in Ecology and Evolution Vol 21 pg 47 Age (years)

44. common tern Telomere length in red blood cells of different birds Fig. 1 TRENDS in Ecology and Evolution Vol 21 pg 47 Age (years)

45. albatross TRENDS in Ecology and Evolution Vol 21 pg 47 Telomere length in red blood cells of different birds

46. Leach’s storm petrel Telomere length in red blood cells of different birds Fig. 1 TRENDS in Ecology and Evolution Vol 21 pg 47

47. Zebra finch Leach’s storm petrel common tern albatross Telomere length in red blood cells of different birds, different species have different patterns of telomere length and age Fig. 1 TRENDS in Ecology and Evolution Vol 21 pg 47

48. Fig. 2 TRENDS in Ecology and Evolution Vol 21 pg 47 Telomere length in white blood cells of different aged people. Telomere length generally declines, but there is wide variability

49. Telomeres are non-gene DNA at the ends of DNA strands. Telomeres are more sensitive to DNA damage, and may act as a sensor for overall DNA damage levels in a cell.

50. Does telomere length indicate longevity?

51. THE LANCET Vol 361 pg 393 Telomere length and mortality in people over 60 years old upper 50% of telomere length lower 50% of telomere length proportion surviving % years after initial assessment

52. Telomere length may indicate biological age. Early stress may cause premature telomere degradation.

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

54. How do these mutations arise? CB 18.22

55. Next: more Cell Division and Cancer