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BIMM 120 CH 9

  1. transformation
    importing DNA from environment into cell
  2. fundamental purpose of bacterial gene transfer
    • acquire genes that might be useful
    • faster than mutations
  3. how to make competent cells
    CaCl2 or eletroporation
  4. why do species undergo natural transformation?
    • DNA as food
    • use specific related DNA to repair damaged genome
    • acquire new genes through horizontal gene transfer
  5. how do gram-positive bacteria become competent?
    transformasome complex controlled by quorum sensing communication
  6. how do gram-negative bacteria become competent?
    always competent or become competent when starved
  7. what is conjugation?
    DNA transfer from one bacterium to another via cell-to-cell contact
  8. fertility factor plasmid
    two replication origins
  9. F+ vs F-
    donor/recipient
  10. argobacterium tumefaciens
    • crown gall disease
    • tumor inducing plasmid that can be transferred via conjugation
    • process has been adapted for genetic engineering of crops
  11. transduction
    bacteriophages carry host DNA from one cell to another
  12. how do cells protect from harmful gene transfer?
    restriction endonucleases
  13. generalized vs site-specific recombination
    long stretches of homologous DNA sequences, similar vs short sequences, same
  14. RecA protein
    • scan DNA molecules for homology
    • align homologous regions to form synapse
  15. two reasons for natural mutations
    • chemical shifts in DNA bases that alter DNA base-pairing properties
    • oxidative deamination of bases and formation of apurinic sites
  16. chemical agent mutagens
    • base analogs
    • base modifiers
    • chemical intercalators
  17. electromagnetic radiation mutagens
    • x-rays and gamma rays: break DNA
    • UV rays: form pyrimidine dimers
  18. The Ames test relies on a mutant bacterial strain that is defective in the ____ gene
    hisG
  19. two types of DNA repair pathways
    • error-proof
    • error-prone
  20. five error-proof repair pathways
    • Methyl mismatch repair
    • Photoreactivation
    • Nucleotide excision repair
    • Base excision repair
    • Recombinational repair
  21. transposable elements
    move from one position in DNA to another
  22. insertion sequence
    transposable element flanked by inverted repeats, which are targets for transposase
  23. IS elements transfer by what two mechanisms?
    nonreplicative and replicative
  24. evolution of a gene is based on
    • random genetic changes
    • natural selection
  25. two processes that introduce whole new genes
    • horizontal gene transfer
    • duplication followed by functional divergence through mutations
  26. three types of genomic islands
    • pathogenicity islands
    • symbiosis islands
    • fitness islands
  27. genome reduction
    loss of genes through evolution
  28. T/F - duplication allows for divergent evolution
    true
Author
andrewlee22087
ID
317431
Card Set
BIMM 120 CH 9
Description
bacteriology
Updated

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