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Mitosis PowerPoint Presentation

Mitosis

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Mitosis

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Presentation Transcript

  1. Mitosis Ch. 9.1-9.3

  2. Objectives • Describe how cell reproduction contributes to repair and growth • Structure of a chromosome • Explain cell cycle • Understand mitosis and cytokinesis • Basics of cancer

  3. Two Functions of Cells • Repair • Growth • The outer layer of skin on your arm consists of dead cell. • Constantly replacing each other! • Cells also key in reproduction . . . more on that later

  4. An idea of where we’re at

  5. The DNA • Genetic material located in nucleus of cell • Most of the time it exists as chromatin • Chromatin: • Uncoiled DNA, not visible

  6. ChromosomesHome of the DNA • Cell prepares to divide • Chromatin fibers condense and become… • Chromosomes: • Condensed, visible threads of genetic material • Yarn example • Humans have 46 chromosomes

  7. ChromosomesHome of the DNA • Right before division, the cell duplicates all of it’s chromosomes • Sister Chromatids: • Identical, joined copies of chromosomes • Centromere: • Joining region of chromatids

  8. Check Your Neighbor • Quiz your neighbor on the terms we just learned.

  9. The Cell Cycle Let's Look at 3 examples of cell division (9.1 activity)

  10. The Cell Cycle • All cells divide at different rates • Interphase: • 90% of cycle • Three stages during interphase: • G1 • Synthesis • G2 • Miotic Stage (10%)

  11. Cell CycleStages of Interphase • G1: • Cell grows • Synthesis: • DNA duplicates • G2: • Cell prepares to divide • Cell Cycle Animation and Different Types of Cells That Divide (9.2)

  12. Cell Cycle Video Clip

  13. Check Your Neighbor • Quiz your neighbor on the cell cycle….

  14. Mitosis • Mitosis: • Non-sexual means of cellular reproduction • Four Stages: • Prophase • Metaphase • Anaphase • Telophase • Cytokinesis • Let’s use pipe cleaners to demonstrate the stages of mitosis. Draw them out after you make them.

  15. MitosisProphase • Nuclear envelope dissolves • Spindle forms • Chromosomes visible

  16. MitosisMetaphase • Chromosomes line up along equator • Spindles attach

  17. MitosisAnaphase • Chromatids separate • Pulled towards opposite ends of cell by spindles

  18. MitosisTelophase • Chromatids uncoil • Nuclear envelope re-forms

  19. Cytokenesis • Division of cytoplasm • Two identical daughter cells • Mitosis: Let's watch the real thing!

  20. Hand Jive Metaphase Prophase Anaphase Telophase

  21. Mitosis Quiz • When I pause the movie, you tell me what stage of Mitosis we are in.

  22. Cancer • Family or friends with cancer? • Cancer: • Uncontrollable cell division • Faulty checkpoints • Out of control cell reproduction produces tumors • Benign tumor: • Abnormal mass of normal cells • Malignant tumor: • Mass of cancer cells • Metastasis: • Spreading of cancer cells Activity 9.4 More cancer animation

  23. How a tumor is formed

  24. Proto-oncogenes encourage cell division