CHAPTER 9 Summary
In-Class Activity
Click here to access the Test Banks specifically designed for chapter 2.
Click here to access Application Activities: Meiosis specifically designed for chapter 2.
Cell division is a fundamental feature of life, necessary for normal growth, development, and repair of the body.-
The cell cycle is the sequence of steps that a cell undergoes in order to divide. Stages of the cell cycle include interphase, mitosis, and cytokinesis.
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During mitosis, replicated chromosomes segregate to opposite poles of the dividing cell; during cytokinesis, the cell physically divides into two daughter cells.
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Mitosis takes place in several phases, each of which is important to properly segregate chromosomes into daughter cells.
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Cell cycle checkpoints ensure accurate progression through the cell cycle; repair mechanisms at each checkpoint can fix mistakes that occur, such as DNA damage.
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In the absence of proper checkpoint function, cells can acquire DNA damage during cell division and pass these DNA defects on to daughter cells.
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Mistakes in the course of cell division can lead to cancer, which is unregulated cell division.
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Cancer cells have lost the ability to regulate cell division and reproduce uncontrollably, often eventually forming a tumor.
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Chemotherapy drugs work by interfering with some part of the cell cycle. Taxol works by interfering with separation of sister chromatids by microtubules during mitosis.
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Cancer is often treated with a combination of surgery, chemotherapy, and radiation.
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Chemotherapy and radiation kill all rapidly dividing cells in their path, including both cancer cells and healthy cells, which accounts for the toxicity and side effects of these treatments.
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Many drugs, including some of those used to treat cancer, are extracted from plants.
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Basic scientific research, often funded by the government, is critical to the development of new drugs to treat cancer.
MORE TO EXPLORE
National Cancer Institute http://www.cancer.gov/
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Horwitz, S. B. (2004) Personal recollections on the early development of Taxol. Journal of Natural Products 67:136–138.
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Wall, M. E., and Wani, M. C. (1995) Camptothecin and Taxol: discovery to clinic. Cancer Research 55:753–760.
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Goodman, J., and Walsh, V. (2001) The Story of Taxol: Nature and Politics in the Pursuit of an Anti-Cancer Drug. Cambridge, UK: Cambridge University Press.
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Stephenson, F. (2002) A Tale of Taxol. Florida State University Research in Review 12(3). http://www.rinr.fsu.edu/fall2002/taxol.html
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Hirsch, J. (2006) An anniversary for cancer chemotherapy. JAMA 296(12):1518–1520.
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