Microbiology Exam 3

  1. Name two major differences between bacteria viruses and animal viruses:
    • no tail
    • use chemical attraction
    • have glycoprotiens
    • cannot be induced
  2. What is a virus called without an envelope?
  3. What is the capsid composed of?
  4. What is the name of the process by which a virus envelops itself?
  5. What is the protein coat of a virus called?
  6. What is a virus that infects bacteria called?
    bacteriophage or phage
  7. How are viruses categorized?
    by their nucleic acid
  8. Name the six types of viruses:
    • dsDNA
    • ssDNA
    • dsRNA
    • (+)ssRNA
    • (-)ssRNA
    • retrovirus
  9. What are the two stages of a virus?
    • intracellular (virus)
    • extracellular (virion)
  10. Name the steps in the Lytic Cycle:
    • attachment
    • penetration
    • biosynthesis
    • assembly
    • release
  11. Name the steps of the Lysogenic Cycle or Lysogeny:
    • attachment
    • penetration
    • insertion
    • latency
    • induction
    • then moves to lytic cycle
  12. Name the three ways induction can occur:
    • chemical damage
    • spontaneous damage
    • exposure to UV light
  13. How does the retrovirus work?
    uses reverse transcriptase to create DNA, then RNA, to viral proteins.
  14. Why are viruses difficult to treat?
    Because when a virus buds off, it takes part of the host's envelop. That makes it difficult to kill the virus without harming the host's cells. The virus is also constantly changing and evolving.
  15. Define lytic:
    destroys the cell
  16. Define virulent:
  17. Define temperate:
  18. Define lysogeny:
    period of latency
  19. What is the family name for the ebola virus?
  20. What is the family name for the flu?
  21. Common 20-sided polyhedral capsid:
  22. Name the parts of a bacteriophage:
    • base
    • tail
    • sheath
    • nucleic acid
    • capsid
    • tail fibers
  23. Name the three ways an animal virus can enter a cell?
    • direct penetration
    • membrane fusion
    • endocytosis
  24. Scientists have determined that prion diseases are not caused by a type of slow virus because prions __________.
    contain no nucleic acid
  25. Which of the following types of genetic material is normally found only in certain types of viruses and not in cells?
  26. HeLa cells are an example of a __________ cell culture.
  27. Fertilized chicken eggs are useful for the culture of viruses for all of the following reasons EXCEPT __________.
    they allow bacteriophages to become latent.
  28. In the early 1900s, the virologist F. Peyton Rous discovered __________.
    cancer-causing viruses
  29. What is the advantage of lysogeny to the lambda phage?
    the phage persists for generations in the bacterial chromosome
  30. Each of the following features is common to both bacteriophage and animal virus infections EXCEPT __________.
  31. Name the common ways bacteriophages attach to the outer structures of a bacterial cell:
    • cell wall
    • flagella
    • pili
  32. Negative-sense ssRNA viruses require which of the following enzymes for their replication?
    RNA-dependent RNA transcriptase
  33. Which of the following types of viruses replicates in the cell's nucleus?
  34. Which of the following viruses creates a DNA intermediary molecule from the information in their RNA genomes?
  35. The tail fibers of a bacteriophage are most useful during which of the following stages of the lytic replication cycle?
  36. What is an infectious agent that does not contain any nucleic acid?
  37. What type of molecules are the capsid made out of?
  38. Put the following terms in order, from simplest to most complex: a. virion b. capsomere c. capsid d. nucleocapsid
  39. Most viral genomes are much smaller than the genomes of the cells they infect. Which of the following CANNOT be inferred from this statement?

  40. The outermost layer of a virion fulfills which of the following functions of the virus?
    B)recognition and replication
    c)protection and recognition
    C-protection and recognition
  41. The majority of cases of infant diarrhea are caused by what kind of virus?
    dsRNA viruses
  42. Which of the following would be an appropriate mode of action for a new anticancer drug?
    inactivation of an oncogene
  43. Virus that infects plants:
  44. Prion disease found in deer and elk:
    Chronic Wasting Disease (CWD)
  45. What condition in humans is linked to bovine spongiform encephalopathy?
  46. What are repressed cancer cells called?
    What are they called when they are "turned on"?
    • protooncogene
    • onocogenes
  47. How do viruses causes cancer?
    They can activate protooncogene and/or inhibit the repressor gene from functioning properly.
  48. A clear zone of phage infection in a bacterial lawn is ________.
  49. What is not a criteria for specific family classification of viruses?
    lipid composition
  50. A good bacteria that is affected by a temperate virus and then becomes virulent is defined as what?
    lysogenic conversion
  51. What method is used to count viruses?
    plaque assay
  52. Name the normal alpha helix protein:
    cellular PrP
  53. Name the misfolded beta sheet protein that causes disease and can only be destroyed by incineration:
    prion PrP
  54. Which virus goes to the nucleus -> convert to RNA -> cytoplasm -> protein?
    DNA viruses
  55. Which virus goes to the cytoplasm -> protein?
    RNA viruses
  56. Chemical used to on the skin or tissue to reduce pathogens.
    antiseptic (neosporin cream)
  57. Destruction of most microorganisms and viruses on surfaces or objects:
    disinfectants (Lysol Disinfectant)
  58. Method of killing pathogens in a public place is called:
    sanitization (restaurant utensils)
  59. Suspension of reproduction in microorganisms is called:
  60. Destruction of all microorganisms and viruses in or on an object.
    sterilazation (autoclave, incineration, ethylene oxide)
  61. What BSL would anthrax be under?
  62. Is most heat better than dry heat and why?
    most heat because water hold heat at high levels to kill of pathogens.
  63. Name the four types of moist heat:
    • boiling
    • autoclaving
    • pasteurization
    • ultra high sterilization (for prions)

  64. What method is good for killing off sacrophiles like Yesinia and Listeria?
    freezing at 0oC - 7oC
  65. Which method stores at -178o C?
    liquid nitrogen
  66. Which method stores at -110C?
    dry ice (CO2)
  67. Osmotic pressure is good for what organism?
  68. Which method can increase shelf life and used on fruits?
  69. Method to remove microorganisms from blood but viruses can still get through:
  70. Hydrogen peroxide does not make a good antiseptic for open wounds because ___________ in human tissue neutralizes it.
  71. Damage to the cell wall will adversely affect a bacterial cell by enhancing the damaging effects of which of the following? (think barophiles)
    osmotic pressure.
  72. Milk that can be stored for months at room temperature has been treated by which of the following methods?
    ultrahigh sterilization
  73. Which of the following is the LEAST useful indicator of an antimicrobial agent's effectiveness?

  74. Which of the following is NOT a direct mode of action of antimicrobial drugs?

  75. What is meant by selective toxicity?
    Chemotherapeutic agents should act against the pathogen and not the host.
  76. Why are chemotherapeutic agents that work on the peptidoglycan cell wall of bacteria a good choice of drug?
    Humans and other animal hosts lack peptidoglycan cell walls.
  77. Quinolones and fluoroquinolones act against what bacterial target?

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Microbiology Exam 3
study questions for Microbiology exam 3