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Mitosis PowerPoint Presentation

Mitosis

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Mitosis

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  1. Mitosis Melissa Gustray, Mickey Gill, Justin Girone

  2. Mitosis & Meiosis • Mitosis is a form of cell division that occurs in somatic (non-sex) cells and produces two daughter cells from an original cell • New cells are genetically identical • 46 chromosomes • Meiosis is a second form of cell division that occurs only in the cells that give rise to sex cells (sperm and eggs) • Halves chromosome number • Does this so that when the sperm fertilizes the egg, the 46 chromosomes are restored

  3. Interphase • First step in cell division. • Cells replicate genetic information and all organelles. • Divided into phases: • S Phase- synthesis • Cellular components duplicate • G Phase- gap or growth • G1 and G2- specific molecules and structures duplicate (everything but DNA) & cellular growth occurs

  4. Mitosis • Karyokinesis- “nucleus movement”, nuclear contents divide • Cytokinesis- “cell movement”, cytoplasm is equally divided between the two new daughter cells • Continuous cycle broken down into four stages: • Prophase • Metaphase • Anaphase • Telophase

  5. Prophase • First stage of mitosis • Chromatin condenses into chromosomes • Centrioles move to opposite sides of cytoplasm • Nuclear membrane and nucleolus disperse • Microtubules assemble and associate with centrioles and chromatids of chromosomes

  6. Metaphase • Second stage of mitosis • Spindle fibers from the centrioles attach to the centromeres of each chromosome • Chromomsomes align midway between the centrioles

  7. Anaphase • Third stage of mitosis • Centromeres separate, and chromatids of the chromosomes separate • Spindle fibers shorten and pull these new individual chromosomes toward centrioles

  8. Telophase • Final stage of mitosis • Chromosomes elongate and form chromatin threads • Nuclear membranes form around each chromosome set • Nucleoli form and microtubules break down

  9. Possible Video Clip Options: http://www.johnkyrk.com/mitosis.html Or http://www.youtube.com/watch?v=iHF422aDh1o&feature=related