Biology 1001A Lecture 8: Recombination Lecture Oct 7th
15 Mar 2016
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Document Summary
Look at ploidy in meiosis and review mitosis, simutext from owl. Mutations arise spontaneously out of chemical damage, etc. Cannot be prevented (however may be repaired) Even without chemical mutagens in world there would still be mutations. A small number of bases (streisingers model) Insertion mutation: one extra base inserted in the new strand (slippage of new) Deletion: one base deleted in the template strand (slippage of template) Regions of repeated sequence are particularly susceptible to in/dels. However, each base in genome is not equally likely to suffer mutation. Mutation hot spots mutation is more common in these areas. Ionizing radiation can produce reactive ions in cells. Sources of radiation exposure: cosmic, radon, medical, internal, terrestrial, etc. Ionizing radiation creates ros (reactive oxygen) that damages dna: Decay of radioactive iodine and cesium creates ionizing radiation . Iodine has a relatively short half life (1 week); cesium relatively long (30 years)
