1. Ch.12 Warm up 1. Define: genome, gametes, chromatin, chromosome, centromere, kinetochore, checkpoint, Cdk, MPF 2. What is the longest part of the cell cycle? Why? 1. If the diploid number is 46, the haploid number is?

2. Ch. 12 Warm up 1. At the end of mitosis and cytokinesis, how do daughter cells compare with their parent cell when it was in G 1 ? 2. A cell’s DNA was measured at 5 picograms. DNA levels range from 3-6 pgms in the cell cycle. What stage of the cell cycle is this cell in. How do you know? 3. At metaphase, if the haploid number is 3, how many chromatids does this cell have?

3. Ch. 12 Warm up What is the correct phase of the cell cycle/mitosis for the following: A. Most cells that no longer divide or rarely divide are in this phase B. Sister chromatids separate and move apart C. Mitotic spindle begins to form D. Cell plate or cleavage furrow form E. Chromosomes replicate F. Chromosomes line up on equatorial plate G. Nuclear membrane forms H. Chromosomes become visible

4. Ch. 12 Warm up 1. Describe the difference between plant and animal cell division. 2. Measurements of the DNA amount per nucleus were taken. DNA levels ranged from 3-6 picograms per nucleus, what stage of the cell cycle are these cells in? a) One nucleus has 3 pgrms b) One with 6 pgrms c) 5 pgrms 3. Describe binary fission.

5. Ch. 12 Warm up 1. How do we know the cell uses chemical signals? 2. Summarize the cell control system. 3. Compare a cancer cell to a normal cell. What goes wrong?

6. Chapter 12: The Cell Cycle

7. What you must know:  The structure of the duplicated chromosome.  The cell cycle and stages of mitosis.  The role of kinases and cyclin in the regulation of the cell cycle.

8. Cell Cycle : life of a cell from its formation until it divides Functions of Cell Division Functions of Cell Division: Reproduction, Growth and Tissue Repair

9. Cell Division  Process by which cell produces more of their kind  Prokaryotes- binary fission  Eukaryotes- mitosis and meiosis

10. Genome = all of a cell’s genetic info (DNA)  Prokaryote  Prokaryote: single, circular chromosome  Eukaryote  Eukaryote: more than one linear chromosomes  Eg. Human:46 chromosomes, mouse: 40, fruit fly: 8

11. Chromatin  Raw material that gives rise to chromosomes  Long and thin during interphase  Condenses and becomes visible under microscope in mitosis

12. Each chromosome must be duplicated before cell division sister chromatids centromere  Duplicated chromosome = 2 sister chromatids attached by a centromere

13. Categories of Cells Somatic Cells Gametes  Body cells  Diploid (2n): 2 of each type of chromosome  Divide by mitosis  Humans: 2n = 46  Sex cells (sperm/egg)  Haploid (n): 1 of each type of chromosome  Divide by meiosis  Humans: n = 23

14. Phases of the Cell Cycle

15.  The mitotic phase alternates with interphase: G 1  S  G 2  mitosis  cytokinesis  Interphase (90% of cell cycle)  G 1 Phase: cell grows and carries out normal functions  S Phase: duplicates chromosomes  G 2 Phase: prepares for cell division  M Phase (mitotic)  Mitosis: nucleus divides resulting in identical complete copies of chromosomes packaged into two new nuclei  Cytokinesis: cytoplasm divides resulting in two daughter cells

16. Mitosis  Continuous process with observable structural features:  Chromosomes become visible (prophase)  Alignment at the equator (metaphase)  Separation of sister chromatids (anaphase)  Form two daughter cells (telophase & cytokinesis)

17. Phases of Mitosis  Mitosis: (PMAT) Prophase  Metaphase  Anaphase  Telophase

18. Prophase & Prometaphase (Prepare) Nucleus and Nucleolus disappear Chromosomes appear as connected sister chromatids Mitotic spindle (made of microtubles) begins to form Centrosomes (pair centrioles) move to opposite ends of cell (plant cells do not have centrioles)

19. Metaphase & Anaphase (Middle) (Apart) Sister chromatids line up along the middle of the cell Ready to split Sister chromatids split move on microtubles to opposite poles in cell Spindle apparatus pulls sister chromatids to opposite poles

20. Telophase (Two new nuclei) & Cytokinesis  Telophase  Nuclei of newly split cells form  Nucleoli appear  Chromatin uncoils Cytokinesis  Cytoplasm of cell divided  Animal Cells: cleavage furrow  Plant Cells: cell plate forms

21. Cytokinesis in animal vs. plant cells

22. Results of Mitosis Mitosis produces 2 daughter cells The two daughter cells contain the exact same number of chromosomes as the original parent cell Daughter cells are DIPLOID

23. Animal Cell Division

24. Plant Cell Division

25. Which phases of the cell cycle can you identify?

27. The Mitotic Spindle: A Closer Look  The mitotic spindle is an apparatus of microtubules that controls chromosome movement during mitosis  Assembly of spindle microtubules begins in the centrosome, the microtubule organizing center  The centrosome replicates, forming two centrosomes that migrate to opposite ends of the cell, as spindle microtubules grow out from them The spindle includes the centrosomes, the spindle microtubules, and the asters (a radial array of short microtubules) Some spindle microtubules attach to the kinetochores of chromosomes and move the chromosomes to the metaphase plate

28. During anaphase  Chromosomes walked to poles by motor proteins  Kinetochore microtubules shorten at ends as they depolymerize  Nonkinetochore microtubules from opposite poles overlap and push against each other, elongating the cell

29. Prokaryote (Bacteria & Archaea) Division  Simple single-celled organism without nucleus  Genetic material  single circular chromosome of DNA, anchored to cell membrane  Duplicated before division

30. Binary Fission Bacterial cells divide by Binary Fission

31. The Evolution of Mitosis  Since prokaryotes evolved before eukaryotes, mitosis probably evolved from binary fission  Certain protists exhibit types of cell division that seem intermediate between binary fission and mitosis Bacterial chromosome Chromosomes Microtubules Prokaryotes Dinoflagellates Intact nuclear envelope Kinetochore microtubules Kinetochore microtubules Intact nuclear envelope Diatoms Centrosome Most eukaryotes Fragments of nuclear envelope

32. Cell Cycle Control System  Checkpoint = control point where stop/go signals regulate the cell cycle

33. Major Checkpoints 1. G 1 checkpoint 1. G 1 checkpoint (Most important!)  Controlled by cell size, growth factors, environment  “Go”  completes whole cell cycle  “Stop”  cell enters nondividing state (G 0 Phase)  Nerve, muscle cells stay at G 0 ; liver cells called back from G 0 2. G 2 checkpoint  Controlled by DNA replication completion, DNA mutations, cell size 3. M-spindle (Metaphase) checkpoint  Check spindle fiber (microtubule) attachment to chromosomes at kinetochores (anchor sites)

34. G 1 Checkpoint

35. M-spindle Checkpoint: Mitotic spindle at metaphase Kinetochore = proteins associated with DNA at centromere

36. Internal Regulatory Molecules Kinases (cyclin-dependent kinase, Cdk): protein enzyme controls cell cycle; active when connected to cyclin Cyclins: proteins which attach to kinases to activate them; levels fluctuate in the cell cycle

37. Internal Regulatory Molecules MPF = maturation-promoting factor specific cyclin-Cdk complex which allows cells to pass G 2 and go to M phase

38.  Growth Factor: proteins released by other cells to stimulate cell division  Example: For example, platelet-derived growth factor (PDGF) stimulates the division of human fibroblast cells in culture  Density-Dependent Inhibition: crowded cells normally stop dividing; cell-surface protein binds to adjoining cell to inhibit growth  Anchorage Dependence: cells must be attached to another cell or ECM to divide External Regulatory Factors

39. External Regulatory Factors Platelet-derived growth factor (PDGF)

40. Cancer Cells Cancer: disorder in which cells lose the ability to control growth by not responding to regulation.  multistep process of about 5-7 genetic changes (for a human) for a cell to transform  loses anchorage dependency and density-dependency regulation  Cancer Cells  Lack differentiation  Have abnormal nuclei  Form tumors  Undergo metastasis Normal Cells Cancer Cells

41. Tumors = mass of abnormal cells  Benign tumor: lump of cells remain at original site  Malignant tumor: invasive - impairs functions of 1+ organs (called cancer)  Metastasis: cells separate from tumor and travel to other parts of body

42. Cancer Prevention Anyone can get cancer but there are ways to minimize risk:  Don’t smoke, legal or illegal (includes hookahs, chew, 2 nd - hand smoke)  Use sun protection  Exercise and keep weight at ideal level  Eat 5-7 servings of fruit and veggies a day  Use screening/preventative measures-breast/testicle/mole checks  Practice abstinence or use condoms  Vaccines (eg. HPV)

43. 1.Name the phases starting at the top.

44. 1.Name the phase 2.Identify X 3.Identify Y

45. 5. Name the phase

46. 6. Name the phase

47. 10. In humans, each cell (except sex cells) has how many chromosomes? ______ 11. After mitosis, how many daughter cells are produced? _______ 12. After mitosis (in a human cell), each daughter cell has how many chromosomes? _____ 13. How many phases are in MITOSIS? ___________ 14. Which phase of the cell cycle is the longest? _________ 15. During which phase does cytokinesis begin? _________ _