Question 1

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

Accepted Answer

A) True 
 B)False

Question 2

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. 
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.

Question 3

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. 
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.

Question 4

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 minutes 
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 minutes

Question 5

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. 
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.

Question 6

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

Accepted Answer

A) True 
 B)False

Question 7

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). 
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).

Question 8

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. 
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.

Question 9

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

Question 10

Boiling is very effective at removing most common waterborne pathogens.

Accepted Answer

A) True 
 B)False

Question 11

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

Accepted Answer

A) True 
 B)False

Question 12

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

Question 13

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

Accepted Answer

A) True 
 B)False

Question 14

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) 
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)

Question 15

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

Question 16

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 17

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

Question 18

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. 
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.

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

Question 20

Upon heat treatment, bacteria die at a constant proportion.

Accepted Answer

A) True 
 B)False

Exam 5: Control of Microbial Growth

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

Upon treatment with heat or chemicals, bacteria will

Quaternary ammonium compounds are

Which are essentially equivalent treatments?

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

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

Commercial canning processes

Phenolics

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

Boiling is very effective at removing most common waterborne pathogens.

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

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

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

Which of the following methods sterilize the materials?

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

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

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

Glutaraldehyde

Hexachlorophene has been particularly effective against

Upon heat treatment, bacteria die at a constant proportion.

Humans and the Microbial World

The Molecules of Life

Microscopy and Cell Structure

Dynamics of Microbial Growth

Microbial Metabolism: Fueling Cell Growth

The Blueprint of Life, From Dna to Protein

Bacterial Genetics

Biotechnology

Identifying and Classifying Microorganisms

The Diversity of Bacteria and Archaea

The Eukaryotic Members of the Microbial World

Viruses, Viroids, and Prions

The Innate Immune Response

The Adaptive Immune Response

Host-Microbe Interactions

Immunological Disorders

Applications of Immune Responses

Epidemiology

Antimicrobial Medications

Respiratory System Infections

Skin Infections

Wound Infections

Digestive System Infections

Blood and Lymphatic Infections

Nervous System Infections

Genitourinary Tract Infections

Microbial Ecology

Environmental Microbiology: Treatment of Water, Wastes, and Polluted Habitats

Food Microbiology

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