Question 1

Liquid media containing heat-sensitive components would best be sterilized by

Accepted Answer

A)   ultraviolet (UV)  light at 500 nm.
B)   membrane filtration.
C)   freezing.
D)   lyophilization.
E)   refrigeration.F) A) and D)
G) A) and E)

Question 2

Jasmine's boyfriend Paul has a large boil on his back. The boil is very painful to touch, and is surrounded by an area of redness that is warm to the touch. Jasmine tells you that she and Paul have decided that Jasmine will "pop" the boil later that evening when they are both home from school. You ask Jasmine what she plans to use to open the boil and she tells you she has a knife with a sharp point that she will use, and that she will wash it well with dishwashing detergent before she uses it.

-You tell Jasmine that it is important that she use a sterile instrument to pierce Paul's boil. Jasmine does not know what "sterile" means or why she needs to use something sterile for her "boil surgery," so you explain. Select the best answer.

Accepted Answer

A)   A sterile instrument is free of all most pathogens but not environmental organisms. Jasmine needs to use a sterile blade because it will come into contact with Paul's tissues, and is thus a semi-critical instrument.
B)   A sterile instrument is free of most microbes. Jasmine needs to use a sterile blade because it will come into contact with Paul's tissues, and is a critical instrument, although the risk for infection is low.
C)   A sterile instrument comes in a sealed pack and is returned to that before its next use. Jasmine needs to use a sterile blade because it will come into contact with Paul's tissues, and is thus a critical instrument.
D)   A sterile instrument is free of all microbes, endospores, and viruses. Jasmine needs to use a sterile blade because it will come into contact with Paul's tissues, and is thus a critical instrument.
E)   The only known sterile instruments are hypodermic syringes, so Jasmine should use that to pop Paul's boil. Syringes are non-critical instruments because they make small wounds. F) All of the above
G) B) and C) D

Question 3

Moist heat kills microorganisms by

Accepted Answer

A)   irreversible denaturation of proteins.
B)   destruction of carbohydrates in the cell wall.
C)   denaturation of nucleic acids.
D)   dissolving the capsule.
E)   destruction of the nuclear envelope.F) A) and D)
G) D) and E)

Question 4

Which of the following is/are not (a)  sterilization method(s) ?

Accepted Answer

A)   Hot air oven
B)   Autoclave
C)   Pasteurization
D)   Filtration
E)   Pasteurization AND autoclavingF) A) and E)
G) All of the above C

Question 5

Dry heat takes a much shorter time to sterilize material than wet heat.

Accepted Answer

A) True 
 B)False

Question 6

Which is True of iodine?

Accepted Answer

A)   It readily kills endospores.
B)   It may be used as an antiseptic but not as a disinfectant.
C)   It can be used at any dilution.
D)   It is usually found as tinctures or iodophors.
E)   It may be used as a disinfectant but not as an antiseptic.F) A) and D)
G) B) and D)

Question 7

Which would be most effective against Pseudomonas?

Accepted Answer

A)   Alcohol
B)   Radiation
C)   Quaternary ammonium compounds
D)   Iodophors
E)   Hand soapF) None of the above
G) C) and E)

Question 8

The process of killing or removing all of the microorganisms in or on a material is called

Accepted Answer

A)   sterilization.
B)   disinfection.
C)   sanitation.
D)   antisepsis.
E)   degerming.F) A) and D)
G) B) and D)

Question 9

Select the False statement regarding hydrogen peroxide.

Accepted Answer

A)   It is a sterilant for inanimate objects and is quickly inactivated on living tissue.
B)   It leaves no toxic residue and is safe on materials such as glass and plastic.
C)   It is broken down by catalase into water and oxygen.
D)   It is even more effective when used in combination with peracetic acid.
E)   It immediately kills all bacteria when applied to a wound.F) C) and D)
G) D) and E)

Question 10

Please select the True statement regarding preservation of perishable products.

Accepted Answer

A)   Nitrites and nitrates are always converted into carcinogens by intestinal bacteria.
B)   Refrigeration destroys most pathogens and all spoilage microorganisms.
C)   Salting and drying increase the availability of water in food above the limits required for growth of most microbes.
D)   Drying stops microbial growth, and reliably kills all bacteria and fungi in or on foods.
E)   Bacterial resistance to some of the chemicals included to perishable products has been reported.F) C) and D)
G) A) and E)

Question 11

A sterile item is free of

Accepted Answer

A)   microbes, viruses, AND prions.
B)   microbes, endospores, AND viruses.
C)   endospores, viruses, AND prions.
D)   microbes, endospores, AND prions.
E)   prions only.F) B) and D)
G) A) and C)

Question 12

Oxidation of proteins is achieved most readily

Accepted Answer

A)   by moist heat.
B)   by moist heat under pressure.
C)   in a hot air oven.
D)   in the presence of organics.
E)   in a refrigerator.F) B) and D)
G) None of the above

Question 13

Lister developed his ideas on prevention of infection during medical procedures after studying the work of

Accepted Answer

A)   Koch.
B)   Pasteur.
C)   Jenner.
D)   Fleming.
E)   Ehrlich.F) A) and B)
G) B) and D)

Question 14

Pasteurization results in the sterilization of food products.

Accepted Answer

A) True 
 B)False

Question 15

Organic acids, such as benzoic acid, are often added to foods to prevent microbial growth.

Accepted Answer

A) True 
 B)False

Question 16

Upon heat treatment, bacteria die at a constant proportion.

Accepted Answer

A) True 
 B)False

Question 17

Microwaves do not kill organisms directly but kill by

Accepted Answer

A)   the heat they generate in a product.
B)   generating free radicals.
C)   generating toxins.
D)   creating thymine dimers.
E)   decreasing the pressure in the cells.F) A) and B)
G) A) and D) A

Question 18

Chemical germicides

Accepted Answer

A)   may react irreversibly with proteins/enzymes.
B)   may react with cytoplasmic membranes or viral envelopes.
C)   may be disinfecting or even sterilizing.
D)   are sensitive to dilution factor, time of contact, and temperature of use.
E)   All of the answer choices are True.F) C) and D)
G) None of the above

Question 19

The more bacteria one starts with, the longer it will take to kill them all.

Accepted Answer

A) True 
 B)False

Question 20

Quaternary ammonium compounds are

Accepted Answer

A)   cationic detergents that help wash surfaces.
B)   attracted to the positive charge on the microbial cell surface.
C)   toxic and cannot be used on food preparation surfaces.
D)   very effective against endospores and non-enveloped viruses
E)   anionic detergents that help wash surfaces.F) All of the above
G) A) and B)

Exam 5: Control of Microbial Growth

Liquid media containing heat-sensitive components would best be sterilized by

Correct Answer
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Correct Answer
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D

Moist heat kills microorganisms by

Correct Answer
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Which of the following is/are not (a) sterilization method(s) ?

Correct Answer
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C

Dry heat takes a much shorter time to sterilize material than wet heat.

Correct Answer
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Which is True of iodine?

Correct Answer
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Which would be most effective against Pseudomonas?

Correct Answer
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The process of killing or removing all of the microorganisms in or on a material is called

Correct Answer
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Select the False statement regarding hydrogen peroxide.

Correct Answer
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Please select the True statement regarding preservation of perishable products.

Correct Answer
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A sterile item is free of

Correct Answer
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Oxidation of proteins is achieved most readily

Correct Answer
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Lister developed his ideas on prevention of infection during medical procedures after studying the work of

Correct Answer
verified

Pasteurization results in the sterilization of food products.

Correct Answer
verified

Organic acids, such as benzoic acid, are often added to foods to prevent microbial growth.

Correct Answer
verified

Upon heat treatment, bacteria die at a constant proportion.

Correct Answer
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Microwaves do not kill organisms directly but kill by

Correct Answer
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A

Chemical germicides

Correct Answer
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The more bacteria one starts with, the longer it will take to kill them all.

Correct Answer
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Quaternary ammonium compounds are

Correct Answer
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Exam 5: Control of Microbial Growth

Liquid media containing heat-sensitive components would best be sterilized by

Correct AnswerverifiedShow Answer

Correct AnswerverifiedD

Moist heat kills microorganisms by

Correct AnswerverifiedShow Answer

Which of the following is/are not (a) sterilization method(s) ?

Correct AnswerverifiedC

Dry heat takes a much shorter time to sterilize material than wet heat.

Correct AnswerverifiedShow Answer

Which is True of iodine?

Correct AnswerverifiedShow Answer

Which would be most effective against Pseudomonas?

Correct AnswerverifiedShow Answer

The process of killing or removing all of the microorganisms in or on a material is called

Correct AnswerverifiedShow Answer

Select the False statement regarding hydrogen peroxide.

Correct AnswerverifiedShow Answer

Please select the True statement regarding preservation of perishable products.

Correct AnswerverifiedShow Answer

A sterile item is free of

Correct AnswerverifiedShow Answer

Oxidation of proteins is achieved most readily

Correct AnswerverifiedShow Answer

Lister developed his ideas on prevention of infection during medical procedures after studying the work of

Correct AnswerverifiedShow Answer

Pasteurization results in the sterilization of food products.

Correct AnswerverifiedShow Answer

Organic acids, such as benzoic acid, are often added to foods to prevent microbial growth.

Correct AnswerverifiedShow Answer

Upon heat treatment, bacteria die at a constant proportion.

Correct AnswerverifiedShow Answer

Microwaves do not kill organisms directly but kill by

Correct AnswerverifiedA

Chemical germicides

Correct AnswerverifiedShow Answer

The more bacteria one starts with, the longer it will take to kill them all.

Correct AnswerverifiedShow Answer

Quaternary ammonium compounds are

Correct AnswerverifiedShow Answer

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D

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C

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A

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