1. Cell Cycle AP Biology Chapters 12-13

3. Remember the Cell Theory! All Living things are made of cells. All cells reproduce to create new cells Cells are the basic unit of structure and function in all living things.

4. CHAPTER 12 HIGHLIGHTS The Cell Cycle Somatic cells vs. gametes Cell Cycle Interphase (3 stages)….mitosis…..cytokinesis

5. Terms for DNA in different stages

6. Chromosome Duplication Remember- each shape of DNA acquires a new name.

7. Cell Cycle

8. NOTE ON THE NEW EXAM Paperwork from the college board states that students do not have to know the names and what happens in each step of mitosis… HOWEVER I have seen their questions. If you don’t know PMAT, you will STRUGGLE to answer their questions! It’s quick and easy- just learn it!

10. Onion mitosis

11. Whitefish mitosis

12. Stages of Mitosis in Detail

13. Spindles and Kinetochores Centrosome- organelle that organizes microtubules for the cell Spindle- microtubules in the cell that form during prophase Kinetochore- structure of proteins and specific sections of chromosomal DNA at the centromere

14. Kinetochores

15. Cytokinesis in animals- cleavage

16. Cytokinesis with cell walls- cell plates

17. Binary fission Prokaryotic cell division DNA loop duplicates Origin of replication zones move to opposite ends of cell Plasma membrane grows in and new cell wall forms Next pictures

18. Binary fission in pictures

19. Evolution of mitosis

20. Regulation of Cell Cycle

21. Molecular control of cell cycle

22. Explanation of molecular control Protein kinases- enzymes that give “go-ahead” signals at checkpoints Protein kinase + cyclin = activation and “go-ahead” begins Cdk- cyclin dependent kinases MPF (maturation promotion factor)- complex of cyclin + kinase Cyclin increases in G1, S, G2 Cyclin decreases sharply in M

23. Messages from kinetochores Anaphase can’t happen until all kinetochores are attached to spindle microtubles in metaphase APC- anaphase promoting complex becomes active then, triggers breakdown of cyclin and inactivation of proteins holding sister chromatids together NOTE it is unlikely that the exam will specifically ask you what APC, MDF, and Cdk do. You should know cyclin’s job and the generic job of protein kinases.

24. Growth factors Protein released by body cells telling other cells to divide PDGF- platelet derived growth factors made by platelets Yet another example to help you understand the role of proteins in the cell cycle and the their bigger application in the human body. Needed for fibroblasts to divide (connective tissue cells with PDGF receptors) Leads to tyrosine kinase receptor pattern….go back and review!!!

25. Practical application PDGF receptors are responsible for telling fibroblasts to divide and heal a cut Density dependent inhibition- when a single layer of cells forms and fills all space available, division stops Anchorage dependence- cells must be attached to a surface to divide

26. Cancer Cells Break Every Rule Lack density dependent inhibition Lack anchorage dependence

27. Cancer terminology Transformation- normal cell  cancer cell Tumor- mass of transformed cells that are not destroyed Benign tumor- stay at original site Malignant tumor- invasive tumor, impairs more than one organ Metastasis- spread of cancer cells Cancer patients have malignant tumors

28. How might cancer cells work??? 1. do not need growth factors? 2. make their own growth factors? 3. abnormality in cell cycle control system? We do know that they don’t follow normal checkpoints in cell cycle Are immortal if given constant nutrients (HeLa since 1951)

29. What makes a cell transform? Alteration of genes that control cell cycle How this happens, still a mystery!

30. CHAPTER 13 HIGHLIGHTS Meiosis and Sexual Life Cycles Basic terms: Heredity Variation Genetics Genes Asexual vs sexual reproduction

31. Visible forms of Human DNA Somatic cells 46 chromosomes Karyotypes

33. Key words for karyotypes Autosomes v sex chromosomes Haploid cells v diploid cells Fertilization  zygote

34. Human life cycle

35. Comparison of Sexual life cycles We will learn the generic form of alternation of generations NOW in order to make the plant unit shorter later this year.

36. Alternation of generations Both diploid and haploid multicellular stages Many variations –Plants, fungi, some protists Sporophyte- diploid Produces haploid spores Divides with mitosis to create a multicellular gametophyte Produces haploid gametes with mitosis Syngamy forms diploid organism

37. Example Alternation of generations

38. Summary of meiosis As in general biology, you only need to learn the timing and important of crossing over, and the differences/similariti es b/n mitosis and meiosis.

39. Steps of Meiosis in Pictures

40. Comparing Mitosis and Meiosis

41. Independent assortment

42. Independent assortment of chromosomes All chromosomes are randomly arranged during metaphase I Calculate out….about 8 million possible combinations of chromosomes for each individual human conceived Ensures variety in the human species

43. Crossing over

44. Crossing Over Prophase I meiosis Chromosomes get mixed up- recombinant chromosomes form Causes variety in the human species

45. Random Fertilization One egg + one sperm = zygote Each egg has 1 of 8 million combinations of chromosomes, Each sperm has one of 8 million combinations of chromosomes + crossing over (impossible to quantify) There are trillions of possible combinations for that child

46. Human Variation

47. Evolutionary Dead End There are 9000-12000 cheetahs left in the world, and they live in a relatively small portion of the world (Namibia mainly). Therefore, all cheetahs are essentially inbred. DNA tests have shown that every cheetah tested has nearly identical DNA. Demonstrates the importance of needing a large pop for genetic diversity.

48. Link to Evolution Variation is what causes natural selection to happen Sexual reproduction creates this variation No matter how the earth changes…some organisms will be able to survive and deal with the changes