BIOL 2051 Study Guide - Horizontal Gene Transfer, Chromosome, Radiography
Document Summary
Chapter 9 gene transfer, mutations, and genome evolution. 1: dna sequence is not static (means it changes) Horizontal gene transfer mechanisms: transformation, transduction, conjugation. Spreads useful genes among bacteria: antibiotic-resistance genes. Spread wherever antibiotics are overused (ex: hospitals, farms: pathogenicity islands. Encode genes for cell to act as pathogen. Difference between typical e. coli in gut and pathogenic e. coli o157:h7: genes to degrade special metabolites (ex: oil spills) Competent cell picks up free dna (from a dead cell etc. ) from the environment. Some cells can be made competent in lab: salt treatments neutralize charge on cell so dna is not repelled, electroporation electrical shock opens pores in cell membrane dna enters through pores. If free dna isn"t incorporated into chromosome, it will be degraded. Dna is packaged into viral capsid is transferred from one bacterium to another by a virus: normally viral dna is packaged, rarely, bacterial dna is packaged by mistake. Can bring new bacterial genes to host.
