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 B)
G) A) and C)

Question 2

One of the first chemicals used by Lister to prevent surgical infections was

Accepted Answer

A)   alcohol.
B)   iodine.
C)   carbolic acid.
D)   mercury.
E)   soap.F) A) and E)
G) C) and D)

Question 3

Boiling is very effective at removing most common waterborne pathogens.

Accepted Answer

A) True 
 B)False

Question 4

Upon treatment with heat or chemicals, bacteria will

Accepted Answer

A)   all die immediately.
B)   die at a constant proportion.
C)   die at an exponential rate.
D)   die at a geometric rate.
E)   always become resistant.F) A) and E)
G) A) and D)

Question 5

Your brother goes on to explain the concept of decimal reduction (D-value)  time to you. To illustrate his point, he tells you that if the D-value for Giardia was 3 minutes and the starting number of cells was 104, the time it would take to eliminate all of the Giardia cells would be

Accepted Answer

A)   15 minutes.
B)   3 minutes.
C)   10 minutes.
D)   9 minutes.
E)   12 minutes.F) C) and D)
G) A) and E)

Question 6

Which of the following methods sterilize the materials?

Accepted Answer

A)   Pasteurization
B)   High-temperature-short-time pasteurization (HTST) 
C)   Ultrahigh-temperature (UHT)  method
D)   Medium-temperature-intermediate-time pasteurization (MTIT) 
E)   Low-temperature-short-time pasteurization (LTST) F) A) and E)
G) A) and B)

Question 7

Glutaraldehyde

Accepted Answer

A)   is very good for use on heat-sensitive medical items.
B)   inactivates lipids.
C)   does not affect non-enveloped viruses.
D)   is used in gaseous form.
E)   kills bacteria but does not affect endospores.F) A) and D)
G) B) and C)

Question 8

Which are essentially equivalent treatments?

Accepted Answer

A)   Dry 200°C heat for 1.5 hours; wet 121°C heat for 15 minutes
B)   Dry 160°C heat for 1.0 hour; wet 200°C heat for 30 minutes
C)   Dry 121°C heat for 1.5 hours; wet 200°C heat for 15 minutes
D)   Dry 100°C heat for 2.0 hours; wet 100°C heat for 30 minutes
E)   Dry 100°C heat for 30 minutes; wet 100°C heat for 30 minutesF) A) and E)
G) B) and C)

Question 9

Phenolics

Accepted Answer

A)   denature proteins and destroy cytoplasmic membranes.
B)   become ineffective in the presence of detergents or organic material.
C)   such as triclosan have very limited commercial use.
D)   reliably inactivate all groups of viruses.
E)   are ineffective against Mycobacterium species.F) A) and D)
G) C) and D)

Question 10

To reduce or eliminate disease-/spoilage-causing organisms, food is often subjected to

Accepted Answer

A)   heat.
B)   chemical additives.
C)   radiation.
D)   cold.
E)   All of the answer choices are correct.F) A) and D)
G) D) and E)

Question 11

Hydrogen peroxide may be used as a sterilant on living tissue.

Accepted Answer

A) True 
 B)False

Question 12

You ask your brother which method of eliminating microbes is the best in general. He tells you that there is no one perfect method and that various factors must be taken into account when considering any antimicrobial approach. These include all of the following EXCEPT

Accepted Answer

A)   the type of microbes to be controlled.
B)   environmental conditions such as temperature.
C)   whether a potential infection can be easily treated.
D)   situational considerations (is a method practical for the situation?) .
E)   the number of microbes to be controlled.F) C) and E)
G) A) and C)

Question 13

Generally, heavy metals, except silver, have been proven to be too toxic for use on human tissue and are no longer used medically.

Accepted Answer

A) True 
 B)False

Question 14

Commercial canning processes

Accepted Answer

A)   destroy Clostridium botulinum spores, are especially needed on low acid foods, AND are 12D processes (designed to kill 1012 endospores) .
B)   kill all endospores, are especially needed on acidic foods, AND are 12D processes (designed to kill 1012 endospores) .
C)   are especially needed on low acid foods, are 12D processes (designed to kill 1012 endospores) , AND destroy E. coli endospores.
D)   destroy E. coli endospores, are especially needed on acidic foods, AND are 12D (designed to kill 1012 endospores)  processes.
E)   destroy Clostridium botulinum spores, are especially needed on very acidic foods, AND are 12D processes (designed to kill endospores in 12 days) .F) C) and D)
G) None of the above

Question 15

100% ethanol is twice as effective as 60% ethanol at controlling bacteria.

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

The endospores of Pseudomonas make that organism very difficult to kill.

Accepted Answer

A) True 
 B)False

Question 18

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) A) and B)
G) A) and C)

Question 19

Hexachlorophene has been particularly effective against

Accepted Answer

A)   Staphylococcus aureus.
B)   Micrococcus aureus.
C)   Escherichia coli.
D)   Enterobacter aerogenes.
E)   Streptococcus pneumoniae.F) C) and D)
G) A) and E)

Question 20

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

Accepted Answer

A) True 
 B)False

Exam 5: Control of Microbial Growth

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

Correct AnswerverifiedShow Answer

Your brother goes on to explain the concept of decimal reduction (D-value) time to you. To illustrate his point, he tells you that if the D-value for Giardia was 3 minutes and the starting number of cells was 104, the time it would take to eliminate all of the Giardia cells would be

Correct AnswerverifiedShow Answer

Hexachlorophene has been particularly effective against

Correct AnswerverifiedShow Answer

Phenolics

Correct AnswerverifiedShow Answer

Upon heat treatment, bacteria die at a constant proportion.

Correct AnswerverifiedShow Answer

The endospores of Pseudomonas make that organism very difficult to kill.

Correct AnswerverifiedShow Answer

Boiling is very effective at removing most common waterborne pathogens.

Correct AnswerverifiedShow Answer

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

Correct AnswerverifiedShow Answer

Which of the following methods sterilize the materials?

Correct AnswerverifiedShow Answer

Commercial canning processes

Correct AnswerverifiedShow Answer

100% ethanol is twice as effective as 60% ethanol at controlling bacteria.

Correct AnswerverifiedShow Answer

Which are essentially equivalent treatments?

Correct AnswerverifiedShow Answer

One of the first chemicals used by Lister to prevent surgical infections was

Correct AnswerverifiedShow Answer

You ask your brother which method of eliminating microbes is the best in general. He tells you that there is no one perfect method and that various factors must be taken into account when considering any antimicrobial approach. These include all of the following EXCEPT

Correct AnswerverifiedShow Answer

Hydrogen peroxide may be used as a sterilant on living tissue.

Correct AnswerverifiedShow Answer

Quaternary ammonium compounds are

Correct AnswerverifiedShow Answer

Glutaraldehyde

Correct AnswerverifiedShow Answer

To reduce or eliminate disease-/spoilage-causing organisms, food is often subjected to

Correct AnswerverifiedShow Answer

Upon treatment with heat or chemicals, bacteria will

Correct AnswerverifiedShow Answer

Generally, heavy metals, except silver, have been proven to be too toxic for use on human tissue and are no longer used medically.

Correct AnswerverifiedShow Answer

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