Cell Division

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Cell Division
2
Chromosomes

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

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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.

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Interphase
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Introduction to Cell Division
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Mitosis

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

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Introduction to Mitosis
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Prophase

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

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Prophase
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Metaphase

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

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Metaphase
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Anaphase

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

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Anaphase
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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.

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Telophase
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Cytokinesis

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

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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.

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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.

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Cancer