Question 1

The process of filtration is a(n)

Accepted Answer

A)   disinfectant method.
B)   sterilizing method.
C)   sanitization method.
D)   antiseptic procedure.
E)   ineffective method for removing microbes. B

Question 2

Which of the following is the most appropriate pairing of microbe and biosafety level?

Accepted Answer

A)   E. coli, BSL-3
B)   anthrax, BSL-1
C)   Ebola, BSL-2
D)   methicillin-resistant Staphylococcus aureus (MRS
A)  , BSL-2
E)   tuberculosis, BSL-1 D

Question 3

A student is shopping for antibacterial hand cleansers and is trying to decide which one to buy. One is a "waterless" hand gel containing 70% isopropanol, the second is an "antibacterial" hand soap containing triclosan (a phenolic), and the third is a wipe that lists benzethonium chloride (a synthetic quaternary ammonium salt) as the active ingredient. Compare and contrast these cleansers in terms of the action of the antimicrobial ingredient and the level of disinfection (degerming, germistatic, germicidal).

Accepted Answer

All three are germicidal, although not all to the same degree.The alcohol of the waterless hand cleaner is a germicide that disrupts cytoplasmic membranes and denatures proteins.It is not effective against bacterial endospores or fungal spores, and it has limited effect on nonenveloped viruses.The alcohol evaporates quickly, so the germicidal effect is short term.The waterless hand cleaner is an intermediate-level disinfectant and is not an effective degermer.The hand soap contains a phenolic, which also damages cytoplasmic membranes and denatures proteins, and is effective on the same range of microbes as the alcohol.Phenolics are intermediate-level disinfectants that persist on surfaces for long periods of time, providing extended disinfection.If used with running water and the hands are vigorously rubbed, the hand soap can be an effective degermer.Synthetic "quats" (quaternary ammonium compounds) disrupt cell membranes.They are effective against fungi, enveloped viruses, and most bacteria, but not against nonenveloped viruses, nor on endospores.Quats are low-level disinfectants that are germicidal for some microbes.The action of using and discarding the wipe provides some degerming effect.

Question 4

Ultra-high-temperature sterilization effectively

Accepted Answer

A)   reduces microbes that cause spoilage.
B)   removes only mesophilic microbes.
C)   reduces microbes that cause disease.
D)   removes all microbes that cause diseases or spoilage.
E)   reduces microbes that cause disease or spoilage.

Question 5

Washing dishes in the dishwasher with detergent and hot water is a ________ process.

Accepted Answer

A)   antiseptic
B)   disinfecting
C)   sterilizing
D)   sanitizing
E)   degerming

Question 6

Antimicrobial agents that damage nucleic acids also affect

Accepted Answer

A)   the cell wall.
B)   the cell membrane.
C)   the viral envelope.
D)   endospores.
E)   protein synthesis.

Question 7

Quaternary ammonium compounds are disinfectants effective against

Accepted Answer

A)   endospores.
B)   mycobacteria.
C)   nonenveloped viruses.
D)   Pseudomonas aeruginosa.
E)   enveloped viruses.

Question 8

Protozoan cysts are resistant to many disinfection methods.

Accepted Answer

A) True 
 B)False

Question 9

Formalin (37% formaldehyde) is used for

Accepted Answer

A)   antisepsis.
B)   disinfection.
C)   sterilization.
D)   sanitization.
E)   both disinfection and sterilization.

Question 10

Refrigeration is an effective germicidal method.

Accepted Answer

A) True 
 B)False

Question 11

Which of the following is used for microbial control in fresh fruits and vegetables?

Accepted Answer

A)   X rays
B)   ultraviolet light
C)   electron beams
D)   microwaves
E)   gamma rays

Question 12

The physical removal of microbes is called (antisepsis/degerming/disinfection).

Accepted Answer

The answer of The physical removal of microbes is called...

Question 13

Methods of microbial control called ________ arrest the growth of microbes.

Accepted Answer

A)   microbicial
B)   microbistatic
C)   sanitizing
D)   degerming
E)   antiseptic

Question 14

Boiling water for 10 minutes is effective in ridding it of

Accepted Answer

A)   actively growing bacteria.
B)   enveloped viruses.
C)   bacterial endospores.
D)   protozoan cysts.
E)   both growing bacteria and enveloped viruses.

Question 15

Heavy metal and oxidizing agent disinfectants damage (DNA/enzymes/membranes), interfering with microbial metabolism.

Accepted Answer

The answer of Heavy metal and oxidizing agent disinfectants damage...

Question 16

The deadliest, most contagious microbes are studied under conditions of (BSL-4/BSL-3/BSL-2/BSL-1) containment.

Accepted Answer

The answer of The deadliest, most contagious microbes are studied...

Question 17

Which of the following is NOT a feature associated with filtration?

Accepted Answer

A)   nitrocellulose or plastic membrane filters
B)   sterilization of heat-sensitive materials
C)   varying thicknesses of membrane filters used
D)   use of HEPA filters to filter air
E)   ability of some filters to trap viruses and proteins

Question 18

Which of the following describes flash pasteurization?

Accepted Answer

A)   heating at 63°C for 30 minutes
B)   heating at 72°C for 15 seconds
C)   heating at 72°C for 15 minutes
D)   heating at 134°C for one second
E)   passing liquid through steam at 140°C

Question 19

The use of lysozyme during the preparation of cheeses and wines is effective in reducing the numbers of

Accepted Answer

A)   fungi.
B)   viruses.
C)   bacteria.
D)   prions.
E)   all microbes.

Question 20

Elements such as iodine, chlorine, and bromine are examples of (oxidizers/halogens/metals), which are the basis for many effective antimicrobial agents.

Accepted Answer

The answer of Elements such as iodine, chlorine, and bromine...

Exam 9: Controlling Microbial Growth in the Environment