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After completing this unit, you should be able to: Describe the structural organization of the prokaryotic genome and the eukaryotic genome; list the phases of the cell cycle; describe the sequence of events during each phase; list the phases of mitosis and describe the events characteristic of each phase;...
Ch.12 Warm up Define: genome, gametes, chromatin, chromosome, centromere, kinetochore, checkpoint, Cdk, MPF What is the longest part of the cell cycle? Why? If the diploid number is 46, the haploid number is? Ch 12 Warm up At the end of mitosis and cytokinesis, how daughter cells compare with their parent cell when it was in G1? A cell’s DNA was measured at picograms DNA levels range from 3-6 pgms in the cell cycle What stage of the cell cycle is this cell in How you know? At metaphase, if the haploid number is 3, how many chromatids does this cell have? 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 Ch 12 Warm up Describe the difference between plant and animal cell division 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 pgrms b) One with pgrms c) pgrms Describe binary fission Ch 12 Warm up How we know the cell uses chemical signals? Summarize the cell control system Compare a cancer cell to a normal cell What goes wrong? Ch 13 Warm up Compare sexual to asexual reproduction Compare/contrast mitosis to meiosis Describe the events of meiosis Ch 13 Warm up Describe and compare the sexual life cycles How does random assortment, crossing over and random fertilization contribute to genetic variation? Define: locus, karyotype, alternation of generations, synapsis, tetrad, chiasmata Chapter 12: The Cell Cycle 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 Cell Cycle: life of a cell from its formation until it divides Functions of Cell Division: Division Reproduction, Growth and Tissue Repair Animal Cell Division Plant Cell Division Which phases of the cell cycle can you identify? Bacterial cells divide by Binary Fission Cell Cycle Control System Checkpoint = control point where stop/go signals regulate the cell cycle Major Checkpoints G1 checkpoint (Most important!) Controlled by cell size, growth factors, environment “Go” completes whole cell cycle “Stop” cell enters nondividing state (G0 Phase) Nerve, muscle cells stay at G0; liver cells called back from G0 G2 checkpoint Controlled by DNA replication completion, DNA mutations, cell size M-spindle (Metaphase) checkpoint 1 Check spindle fiber (microtubule) attachment to chromosomes at kinetochores (anchor sites) G1 Checkpoint M-spindle Checkpoint: Mitotic spindle at metaphase Kinetochore Kinetochore == proteins proteins associated associated with with DNA DNA at at centromere centromere 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 Internal Regulatory Molecules MPF = maturation-promoting factor • specific cyclin-Cdk complex which allows cells to pass G2 and go to M phase External Regulatory Factors External Regulatory Factors Growth Factor: proteins released by other cells to stimulate cell division 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 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 Normal Cells Cancer Cells 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 Cancer Prevention Anyone can get cancer but there are ways to minimize risk: Don’t smoke, legal or illegal (includes hookahs, chew, 2ndhand 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) ... synapsis, tetrad, chiasmata Chapter 12: The Cell Cycle 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. .. pgms in the cell cycle What stage of the cell cycle is this cell in How you know? At metaphase, if the haploid number is 3, how many chromatids does this cell have? Ch 12 Warm up What is the correct... cell plate forms Cytokinesis in animal vs plant cells Animal Cell Division Plant Cell Division Which phases of the cell cycle can you identify? Bacterial cells divide by Binary Fission Cell Cycle