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26 Cards in this Set
- Front
- Back
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Mutation |
a change in the sequence of DNA Cancer caused by mutations to genes that regulate cell growth and division. Changes to DNA can change the structure and function of the protein coded by the DNA Mutations may be inherited or caused by carcinogens. |
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What are commonly mutated in cancer cells? |
Proto-oncogenes and tumor suppressor genes |
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Proto-oncogenes |
Genes that code for the cell cycle control proteins. When proto-oncogenes mutate, they become oncogenes. They no longer properly regulate cell division. They overstimulate the proteins in cell division. |
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Tumor suppressor genes |
Genes for proteins that stop cell division if conditions are not favorable. Prevent the development of many cells containing mutations. When mutated, can allow cells to override checkpoints. |
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p53 |
tumors suppressor gene that halts cell division if damaged DNA is detected. p53 is absent or damaged in many cancerous cells. |
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Angiogenesis |
Tumor gets its own blood supply |
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Loss of contact inhibition |
Cells will now pile up on each other. |
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Loss of anchorage dependence |
Enables a cancer cell to move to another location. |
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Immortalized |
Cells no longer have a fixed number of cell divisions due to an enzyme called telomerase. |
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Multiple hit model |
Process of cancer development requires multiple mutations. Can be inherited most probably acquired during a person's lifetime. Mistakes during DNA replications. Physical, chemical, radiation based mutagens. Viruses. |
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Biopsy |
Surgical removal of cells or fluid for analysis. Needle biopsy: removal is made using a needle. Laparascope: surgical instrument with a light, camera, and small scalpel. |
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Radiation therapy |
Use of high-energy particles to destroy cancer cells. Damages DNA so can't divide or grow. After surgical removal of tumor. If a person remains cancer free after treatment for 5 years they are in remission and after 10 years they are cured. |
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How to prevent cancer? |
Prevent exposure to mutagens (UV, chemicals, viruses) |
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Meiosis |
Specialized form of cell division in gonads to produce gametes. Reduces number of chromosomes in each cell by one-half. Chromosomes come in homologous pairs Gamete gets one of each pair. |
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Meiosis stages |
Uses the same stages as mitosis but goes through them twice Meiosis 1 (prophase 1, anaphase 1 etc.) Meiosis 2 (prophase 2, anaphase 2 etc.) |
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Mitosis vs. Meiosis |
Occurs during the stages: Crossing over of homologous chromosomes. Homologous chromosomes- chromosomes that carry the same genetic information Ploidy reduction |
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Random alignment |
Metaphase 1: the way in which different pairs of chromosomes align and get separated during meiosis 1 is random. Results in different types of games being formed |
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Meiosis 1 |
Divide homologous pairs into 2 separate cells. Now has 2 copies of half of our chromosome (one of each pair = 46) per cell |
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Meiosis 2 |
Divide sister chromatids in each cell to produce 4 haploid cells. Separate the two copies into two cells (=23) |
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Meiosis 2 resembles a mitotic division |
Prophase 2: nuclear envelopes dissolve and spindle apparatus forms. Metaphase 2: chromosomes align on metaphase plate. Anaphase 2: sister chromatids are separated from each other. Telophase 2: nuclear envelope re-forms; cytokinesis follows. |
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Mistakes in Meiosis |
Large-scale chromosomal alterations have severe impacts caused by miscarriages and a variety of developmental disorders. Common types: Non-disjunction Resulting in aneuploidy (abnormal chromosome #) Direct alteration of chromosome structure. |
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Nondisjunction |
Failure of homologues to separate normally during meiosis. Results in a gamete having one too many chromosomes (trisomy) or one too few chromosomes (monosomy) Most embryos results from such gametes will die before birth. |
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Polyploidy |
3 or more sets of chromosomes. Rare in animals. More common in plants. |
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Genetic counseling |
Pedigree evaluation and genetic testing to inform parents of the risk of passing on a disease. |
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Fetal testing |
Amniocentesis and chorionic villus sampling can provide genetic information on a fetus during pregnancy. |
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Newborn screening |
Some genetic disorders can be detected at birth by simple tests that are now routinely performed in most hospitals in the U.S. |
