Microbiology 250 Exam 3: Questions with Complete Solutions Verified for New Updates.

Which of the following is true about disinfection? A)Bacterial endospores may not be killed on an object B)Fungal spores may not be killed on an object C)Disinfection reduces the number of pathogenic organisms on or in an object D)Disinfection helps reduce the threat of disease E)All of these choices - -E)All of these choices What is the difference between a disinfectant and an antiseptic? A)Disinfectants are typically applied to living tissue and antiseptics are typically applied to inanimate objects B)Disinfectants are typically applied to inanimate objects and antiseptics are typically applied to living t issue C)Disinfectants sterilize an object, whereas an antiseptic does not D)Antiseptics sterilize and object whereas a disinfectant does not E)There is no difference between a disinfectant and an antiseptic - -B)Disinfectants are typically applied to inanimate objects and antiseptics are typically applied to living tissue It is reported that antimicrobial agent X has a 40% death rate per minute. If there are 1000 organisms present in the environment when agent X is applied, how many organisms will remain in the environment after 5 minutes? A)600 B)360 C)130 D)78 E)0 - -D)78 If it was reported that Lysol had a phenol coefficient of 5.0, this would mean that: A)Lysol was less effective than phenol B)Lysol was equally as effective as phenol C)Lysol was more effective than phenol D)All of these choices E)It is impossible to compare Lysol and phenol because they have different methods of action - -C)Lysol was more effective than phenol Why can liquid dish soap be used as an antimicrobial agent, even if it is not labeled as being antibacterial? A)It denatures proteins via hydrolysis reactions B)It is a surfactant and dissolves lipids C)It is a mutagen and damages bacterial DNA D)It is radioactive and causes RNA damage E)None of these choices - -B)It is a surfactant and dissolves lipids Why is phenol considered a good antimicrobial agent? A)Phenol works well in the presence of organic materials B)Phenol cannot damage tissue C)Phenol has a pleasant odor D)Phenol is used to kill gonococci E)All of these choices - -A)Phenol works well in the presence of organic materials Sanitation: A)Kills microorganisms via ionizing radiation B)Kills microorganisms via sound waves C)Inhibits the growth of microorganisms via ionizing radiation D)Inhibits the growth of microorganisms via visible light E)None of these choices - -B)Kills microorganisms via sound waves Which form of radiation would be most effective at killing microorganisms? A)Infrared Light B)UV light C)Gamma Rays D)Visible Light E)X-rays - -C)Gamma Rays An agent that inhibits the growth of bacteria is called a/an: A)antiseptic B)bactericide C)bacteriostatic agent D)sanitizer - -C)bacteriostatic agent What is the most susceptible phase of growth for most microorganisms by an antimicrobial agent? A)lag phase B)log phase C)stationary phase D)death phase - -B)log phase Which is not used to measure the effectiveness of an antimicrobial agent? A)Filter paper method B)Phenol coefficient method C)Use-dilution method D)Plate count method - -D)Plate count method When an antimicrobial agent permanently denatures proteins thus preventing renaturation to their native states it is considered: A)bacteriostatic B)bactericidal C)bacterial lysis D)an inhibitor of growth - -B)bactericidal Soluble compounds that reduce surface tension thus dissolving lipids are kn