Regulation of the Cell Cycle Normal vs' Abnormal Growth of Cells

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Regulation of the Cell CycleNormal vs.
Abnormal Growth of Cells
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Internal and external factors regulate cell
division.

• External factors include physical and chemical
  signals.
• Growth factors are proteins that stimulate cell
  division.
• Most mammal cells form a single layer in a
  culture dish and stop dividing once they touch
  other cells.

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• Apoptosis is programmed cell death.

• a normal feature of healthy organisms
• caused by a cells production of self-destructive
  enzymes
• occurs indevelopmentof infants

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Cell division is uncontrolled in cancer.

• Cancer cells form disorganized clumps called
  tumors.

• Benign tumors remain clustered and can be
  removed.
• Malignant tumors metastasize, or break away, and
  can form more tumors.

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• Cancer cells do not carry out necessary functions.

• Cancer cells come from normal cells with damage
  to genes involved in cell-cycle regulation.

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• Carcinogens are substances known to cause cancer.

• Standard cancer treatments typically kill both
  cancerous and healthy cells.

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Cancer

• Causes of Cancer
• 1. Environmental agents called carcinogens
• 2. Oncogenes cancer genes

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November 14, 2007

• Todays Warm-Up
• At what point do you think mutations could occur
  in mitosis. Why?
• Answer Metaphase and Anaphase. Chromatids are
  being pulled apart.

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• Terms to know
• Define the following 14 terms on your Genetics
  vocab list!
• Meiosis homologous
• Chromosome DNA
• Karyotype DNA Polymerase
• Sex chromosome chromatin
• Diploid autosome
• Haploid crossing over
• tetrad cancer

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Meiosis
Upon fusion of egg and sperm a zygote is formed.
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KEY CONCEPT Gametes have half the number of
chromosomes that body cells have.