BIOLOGY 305 Lecture Notes - Lecture 9: Genetic Distance, Streptomycin, Research In Computational Molecular Biology
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Sections 5. 1-5. 3 (skim 5. 6 for sense of switch from genetic maps to sequence maps) Dna codes for proteins, via rna a copy of dna is passed on to daughter cell: but they are haploid, and reproduce only asexually. May occasionally exchange dna with other organisms [figure 5-2] such exchange is uncommon. Not a central part of their life cycle evolution is through mutation and other accidents . Transformation: direct uptake of dna from the environment, generally from dead and lysed cells, unless this dna has an origin of replication (ori), it must recombine into chromosome. The f plasmid and conjugation (a. k. a. bacterial sex) (joshua) lederberg & tatum (1946: mix multiple auxotrophs [figure 5-5] [figure 5-6] a fine filter (0. 22 m?) blocks the effect. Prevents cell contact but not molecular diffusion. One strain donates its alleles to convert the other. Not random, donors are always donors (male or f+: f+ strains seem to pass on a fertility factor.