Mitosis: Cell Division

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Mitosis Cell Division
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Terminology

• DNA made of nucleic acids, housed in the
  nucleus, contains genes
• Chromatin long strands of DNA that are wrapped
  around proteins (histones)
• Nucleosome the DNA/ histone complex

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Why does mitosis happen?

• Surface area to volume ratio
• As a cell grows, the volume grows faster than the
  surface area
• Not enough space in the cell membrane to send
  wastes out or to bring food in
• Signal is sent to the cell
• An organism needs to grow
• To repair damage

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Structure of a Chromosome

• Chromosome a structure that is made of DNA and
  the proteins associated with it
• Chromatid one of the 2 exact copies of the DNA
  often referred to as sister chromatids the
  2 of them together make a chromosome
• Centromere the point where the 2 chromatids are
  connected together to make a chromosome

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Homologous Chromosomes

• two chromosomes that code for the same traits.
  One is from mom the other is from dad

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Cell Cycle

• Interphase
• Majority of a cells life
• Cell grows
• Chromosomes duplicate
• Mitosis
• Creates 2 daughter cells that are identical to
  the parent cell
• Cell division

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Interphase

• G1
• Growth One
• The cell spends most of its life
• S
• Chromosomes are duplicated
• G2
• Organelles and other parts needed for cell
  division are duplicated

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Mitosis

• Prophase the chromosomes become visible the
  nuclear envelope disappears pro first
• Metaphase the chromosomes line up in the middle
  of the cell
• Anaphase the sister chromatids move away from
  each other
• Telophase begins as chromatids reach opposite
  ends of the cell

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Cytokinesis

• The cytoplasm and organelles are divided between
  the two sides
• Plants
• A cell plate begins forming
• Animals
• A cleavage furrow forms as the
• cell pinches inward

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Levels of Organization
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When Good Cells Go Bad!
Facts about cancer

• Who will develop it?
• ½ of men and 1/3 of women in the U.S. will
  develop cancer in their lifetime
• What is it?
• Uncontrolled cell division
• What causes the cell to keep dividing?
• Failure to produce internal regulators or respond
  to external regulators

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Causes of Cancer

• a.   Tobacco use lung, mouth, esophageal,
  cervical cancer
• b.  Asbestos lung cancer
• c.   Radiation exposure
• d.  Viral infection - HPV
• e.   Charred meat colon cancer
• f.     Genetic
• g.   Chemical exposure
• h.  UV exposure (sun or tanning bed) skin
  cancer
• i. Drinking more than one drink a day for women
  or 2 a day for men

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Kinds of Cancer

• Metastatic
• More dangerous
• Cancer travels in the body

• Nonmetastatic
• Usually less dangerous
• Cancer does not travel

Not all cancers form tumors and not all tumors
are cancerous!
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How does cancer spread?
Pancreatic Cancer