Mitosis and Cancer

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Mitosis and Cancer

• Today you will learn about the process of
  mitosis(normal cell division) and what can happen
  if the cell cycle becomes mutated (abnormal cell
  division).

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Abnormal Cell Growth
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Abnormal Cell Growth
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A Large Abdominal Tumor
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Surgical Removal of Tumor
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Body without Tumor
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MITOSIS
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Why do cells divide?

• Reproduction
• Growth
• Repair

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MITOSIS

• nuclear division
• number of chromosomes remains the same

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Interphase

• technically not part of mitosis, but it is
  included in the cell cycle
• cell is in a resting phase
• performing cell functions
• DNA replicates (copies)
• organelles double in number, to prepare for
  division

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Interphase

• G1 - (Growth 1)
• S - (Synthesis) - DNA copies
• G2 - (Growth 2) - cell prepares for division

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Interphase(inter between)

• The "holding" stage or the stage between two
  successive cell divisions. 90 percent of a
  cell's time in the normal cellular cycle may be
  spent in interphase.

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Prophase(proprimary,first)

• In prophase, the chromatin condenses into
  discrete chromosomes. The nuclear envelope breaks
  down and spindles form at opposite "poles" of the
  cell.

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ProphaseKey Events

• Chromatin coils to form visible chromosomes
• In animals, centrioles begin to migrate to
  opposite poles
• Spindle forms

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What is chromatin?

• When a cell is "resting" i.e. not dividing, the
  chromosomes are organized into an entangled
  structure called chromatin

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Metaphase(meta is like middle)

• In metaphase, the chromosomes are aligned at the
  metaphase plate (a plane that is equally distant
  from the two spindle poles). ?The spindles form
  the framework of the dividing cell.

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Anaphaseanaupward,back

• The centromeres divide and the paired chromosomes
  (sister chromatids) move to opposite ends of the
  cell.

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Telophase(teloend)

• In this last stage, two distinct daughter cells
  are formed after the chomatids have migrated to
  the opposite poles. Cytokinesis is also
  occurring at this time.

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Cytyokinesis

• Cyto cell
• Kinesismovement
• The cells cytoplasm divides at the end of
  telophase
• Animals - cell pinches inward
• Plants - a new cell wall forms between the new
  cells

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Results of Mitosis

• The cell is the most basic unit of organization
• In animals
• cells--gttissue--gtorgans--gtorgan systems
• --gtorganisms
• See pg. 210, Figure 8.16

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The Cell Cycle

• Proteins called cyclins and enzymes that attach
  to the cyclins and become activated control the
  cell cycle

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Cancer

• Occasionally, cells lose control of the cell
  cycle
• This results from
• failure to produce certain enzymes,
• the overproduction of enzymes
• Or the production of enzymes at the wrong time.

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Cancer

• Cancer is a malignant growth resulting from
  uncontrolled cell division
• Malignant dangerous to health marked by
  uncontrolled growth

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Tumors

• Tumors are abnormal growth of cells
• Benign tumors are non cancerous and and only grow
  locally
• Malignant tumors are cancerous and spread to
  other areas of the body

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Cancer

• Cancer is the second leading cause of death in
  the U.S.
• Lung, colon, breast, and prostate cancers are the
  most prevalent types

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Problem Solving Lab 8.3

• Today you will estimate the number of people in
  the U.S. who developed these kinds of cancers in
  the year 2000.

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Causes of cancer

• Genetics
• Environmental Factors
• Cigarette smoke
• Air and water pollution
• Exposure to UV radiation
• However, there are still unknown causes and
  researchers are working to discover these factors.

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Cancer prevention

• Healthy Lifestyle
• Low fat, high fiber diet
• Exercise
• Not smoking
• Taking daily vitamins and minerals
• Carotenoids, Vitamins A, C, E, and calcium

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Cancer

• Cancer is difficult to treat in later stages
  because the cancer may have spread to vital
  organs and damaged them beyond repair.
• Today we will see a short video that shows how
  widespread cancer can affect the body.