MICROBIOLOGY: PRACTICE 1

SINGLE BEST OPTION SERIES

         INSTRUCTION: SELECT THE SINGLE BEST OPTION

1.        The phases of bacterial growth curve reflection of the events in a population of cells, not in individual cells. This type of culture is best referred to as:
   a.       Batch culture
   b.      Continuous culture
   c.       Viable but not culturable
   d.      Fastidious
   e.      None of the above
   2.       Phases of bacterial growth curve does not include:
   a.       Stationary phase
   b.      Maximum stationary phase
   c.       Multiplication phase
   d.      Death or logarithmic phase
   e.      Log or exponential growth phase
   3.       Which of the following is incorrect about the lag phase of bacterial growth:
   a.       The bacterial cell mass increases in an exponential manner
   b.      The bacterial cells adapt to their new environment
   c.       Enzymes and intermediates are formed and accumulate until they are sufficient to permit growth
   d.      The growth rate is zero
   e.      None of the above
   4.       Which of the following statement is incorrect about biocides:
   a.       Bacteriostatic biocides inhibit bacterial multiplication
   b.      Bactericidal action is usually irreversible
   c.       Sterilization renders a product free from viable organisms but not the bacterial spores
   d.      Disinfectants reduce the number of viable micro-organisms or bio-burden on a product or surface.
   e.      Preservation is the prevention of multiplication of micro-organisms in formed products
   5.       The following are used for disinfection except:
   a.       Cetrimide
   b.      Hydrogen peroxide
   c.       Ethylene oxide
   d.      Chlorhexidine
   e.      None of the above
   6.       The following are used for sterilization in microbiology laboratory except:
   a.       Chlorhexidine
   b.      Ethylene oxide
   c.       Ozone
   d.      Glutaraldehyde and formaldehyde
   e.      None of the above
   7.       The following are usual modes of action of biocides except:
   a.        Damage to DNA
   b.      Protein denaturation
   c.       Removal of free sulfhydryl groups
   d.      Chemical antagonism
   e.      None of the above
   8.       The action of which of the following agents or processes on bacteria can be reversed:
   a.       A disinfectant
   b.      A bactericidal agent
   c.       A bacteriostatic agent
   d.      Autoclaving at 121⁰C for 15 minutes
   e.      Dry heat 160 to 170⁰C for one hour
   9.       Which of the following is incorrect about the following chemical biocides?
   a.       Glutaraldehyde is used at low temperature for disinfection and sterilization of endoscopes
   b.      Ethyl and isopropyl alcohol are sporicidal
   c.       Mycobacterium are highly resistant to chlorhexidine
   d.      Povidone-iodine is rapidly tuberculocidal
   e.      None of the above
   10.   Which of the following is incorrect:
   a.       Chlorhexidine is a disinfectant
   b.      Bisphenols have little activity against Pseudomonas aeruginosa
   c.       Iodine is virucidal and sporicidal
   d.      Povidone-iodine are complexes of iodine and a carrier
   e.      None of the above
   
   
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