BIOL239 Lecture Notes - Axa, Amine, Dna Repair
13 Sep 2014
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Substitution: evolution: adaptation vs. mutation, mutations are chance occurrences modifying the genome. 1943 salvador luria and max delbruck (before dna structure was resolved) Used e. coli and bacteriophage t1 (they replicate quickly so you get results fast) to test hypotheses regarding the mechanisms responsible for appearance of a new phenotype (luria-delbruck jackpot"; fluctuation test) Phage will usually kill all the bacteria but some will survive (somewhat resistant like for antibiotics) Do they adapt because they"re exposed to the phage or is the resistance already there: know this experiment and the scientists who performed it, the luria-delbruck experiment. Set up small vials of bacterial culture and let them grow for a specified amount of time then add equal portions of each culture to plates containing media along with phage (selective agent) Predicted that most will die but some will live. Mistakes in dna occur at a low frequency all the time. Natural processes of deamination, uv light, errors by dna polymerase.
