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2015-11-16 16:27:30
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  1. bacteria and viruses are diploid or haploid?
  2. auxotroph vs prototroph
    • phototrophs are organisms that can synthesize all the compounds needed for growth. (can be grown on minimal medium)
    • auxotrophs cannot synthesize one or more of the necessary compounds  for growth
  3. 3 ways bacteria transfer genetic information...
    • conjugation
    • transformation
    • transduction
  4. conjugation between F+x F- results in what types of exconjugants?
    • F+x F- results in two F+ cells
    • process: pilus, one strand of plasmid moves across, DNA complement synthesized on both single strands, cells separate
  5. how does F+ cell become Hfr cell?
    F factor is integrated into the bacterial chromosome
  6. Hfr x F- results in what types of exconjugants?
    • Hfr x F- results in an Hfr cell and an F- cell with extra genes
    • process: bacterial chromosome integrates F factor and becomes Hfr, Hfr able to conjugate with F- cell and transfer some genes, F factor does not transfer
  7. what is an F' cell?
    when the F factor that had been integrated into the Hfr chromosome excises it brings a few genes along with it
  8. F' x F- what types of exconjugants?
    • F' and a merozygote (also F')
    • process: F factor of Hfr cell excises from chromosome bringing a few genes along, now considered F', when crossed with F-, the F factor along with the excised genes are transferred and the recipient cell now may have two copies of those genes, a merozygote considered partially diploid
  9. F factor plasmids vs R plasmids
    • F factor plasmids confer fertility; genes for sex pilus
    • R plasmids have resistance transfer factor (RTF) that codes for plasmid transfer AND r-determinants that confer resistance to antibiotics
  10. Viral DNA that integrates into the bacterial chromosome is called a ______
  11. episome
    viral DNA that can be integrated in to the host DNA or replicated in the bacterial cytoplasm
  12. to serve as genetic material a molecule must be able to satisfy these 4 criteria:
    • replicate
    • store information
    • express information
    • allow variation by mutation
  13. central dogma of molecular genetics
    • transcription: three types of RNA are synthesized from DNA
    • mRNA - messenger
    • rRNA - ribosomal
    • tRNA - transfer
    • translation: mRNA synthesizes proteins
    • DNA-->transcription[m/r/t RNA]-->ribosome-->translation-->protein
  14. Griffith experiment
    • 1927 - rats - avirulent strains could be transformed to virulence
    • some "transforming principle" exists
    • Rough was avirulent
    • Smooth was virulent
    • Heat-kill Smooth, avirulent
    • combine with Rough
    • virulent
  15. Avery experiment
    • "transforming principle" was DNA
    • treated cells with different enzymes to selectively remove protein, RNA, or DNA -- only when DNA was removed did transformation not occur
  16. Hershey and Chase experiments
    • 1952
    • - DNA, not protein, genetic material
    • used E. coli and bacteriophage
    • using radioisotopes 32P and 35S
    • 32P w/ phosphate backbone of DNA
    • 35S w/ sulfur of protein bodies of bacteriophage
  17. retroviruses - unusual replication
    • RNA serves as template for synthesis of complementary DNA by the RNA-dependent DNA polymerase, reverse transcriptase
    • This DNA can be incorporated into the host-cell genome. 
    • When transcribed copies of original retroviral RNA chromosomes also produced
  18. DNA is a nucleic acid
    nucleotides are the building blocks of DNA. 
    Nucleotides consist of ...(3)
    • nitrogenous base
    • pentose sugar
    • phosphate group
  19. two kinds of nitrogenous bases and types of each na d
    • Purines: Adenine and Guanine; double ring structure
    • Pyrimidines: Thymine (or Uracil) and Cytosine; single ring structure
  20. 2' C difference between deoxyribose and ribose
    • Ribose = OH
    • Deoxyribose = H
  21. what type of bond links nucleotides?
    specifically where does this bond exist?
    phosphodiester bond between the phosphate group at the C-5' and the OH group at the C-3' position
  22. Watson and Crick year
    DNA diameter
    space between base pairs
    length of one complete turn
    minor groove and major groove
    right or left handed
    • 1953
    • 2 nm
    • .34 nm
    • ten base pairs = 3.4 nm
    • 1.2 nm and 2.2 nm
    • right handed
  23. number of hydrogen bonds between base pairs
    • A:T = 2
    • G:C = 3
  24. DNA replication is semiconservative experiment...
    who, when, how
    • Meselson and Stahl
    • 1958
    • Used 15N-labeled E. coli in a medium containing 14N
    • -- in prokaryotes
  25. telomeres
    • long stretches of short repeating sequences at the ends of linear chromosomes
    • preserve integrity and stability of chromosomes
    • active in germ cells -- NOT eukaryotic somatic cells
  26. chromosomes -- viral vs bacterial vs eukaryotic
    • viral -- DNA or RNA, single or double stranded, circular or linear
    • bacterial -- DNA, circular, double stranded, few proteins
    • eukaryotic -- DNA, linear, double stranded, many proteins
  27. levels of DNA packaging
    2nm DNA --> 11nm nucleosome --> 30nm solenoid --> looped domains --> 300nm chromatin fibers --> 700nm chromatid --> 1400nm chromosome
  28. Satellite DNA
    highly repetitive, short repeated sequences found in heterochromatic centromeric regions of chromosomes
  29. VNTR
    • Variable Number Tandem Repeats
    • minisatellites
  30. STR
    • Short Tandem Repeats
    • microsatellites
  31. SINE
    Short Interspersed ElementsLong Interspersed Elementsdispersed throughout genomeThey are retrotransposons that are generated via an RNA intermediate