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Cell Division

Cell Division

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Cell Division

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Presentation Transcript

  1. Cell Division

  2. Chromosomes • Are made of DNA • Each chromosome consists of sister chromatids attached at a centromere

  3. Cell Cycle • During the cell cycle, a cell grows, prepares for division, and divides to form 2 daughter cells, each with each of which then begins the cycle again. • Interphase – time for growth and regular cell activity. • Most of a cells life is spent in Interphase.

  4. Interphase

  5. Introduction to Cell Division

  6. Mitosis • The division of somatic or regular cells. • Its divided into 4 phases. • Remember Interphase is NOT part of Mitosis.

  7. Introduction to Mitosis

  8. Prophase • First stage of Mitosis • Chromatin condenses into chromosomes • Centrioles separate and a spindle fiber begins to form. • Nuclear membrane breaks down

  9. Prophase

  10. Metaphase • Second Phase of Mitosis • Chromosomes line up in the middle of the cell. • Each chromosome is connected to a spindle fiber.

  11. Metaphase

  12. Anaphase • Third Phase of Mitosis • The sister chromatids separate into individual chromosomes and move apart to opposite ends of the cell.

  13. Anaphase

  14. Telophase • Fourth and Final Stage of Mitosis • Chromosomes gather at opposite ends of the cell and lose their distinct shapes • Two new nuclear membranes have formed.

  15. Telophase

  16. Cytokinesis • The cytoplasm pinches in half. • Each daughter cell has an identical set of duplicate chromosomes

  17. Regulating the Cycle • A protein call cyclin helps regulate the cell cycle in eukaryotic cells. • They respond to internal and external events. These proteins are regulators.

  18. When Things Go Wrong • Cancer cells do not respond to the signals that regulate the growth of most cells. • As a result, they form masses of cells called tumors that can damage surrounding tissues.

  19. Cancer