Question 1

Ultraviolet radiation at the bactericidal wavelength destroys bacteria by

Accepted Answer

A)  destroying endospores. 
B)  damaging nucleic acid. 
C)  preventing spore formation. 
D)  denaturing proteins. 
E)  disrupting ribosomes. 
A)  destroying endospores. 
B)  damaging nucleic acid. 
C)  preventing spore formation. 
D)  denaturing proteins. 
E)  disrupting ribosomes.

Question 2

The autoclave treatment may be monitored by

Accepted Answer

A)  heat-sensitive tape AND pressure indicators. 
B)  heat-resistant endospores of Geobacillus stearothermophilus. 
C)  pressure indicators AND waiting for contaminants to appear on freshly poured media. 
D)  waiting for contaminants to appear on freshly poured media. 
E)  heat-sensitive tape AND heat-resistant endospores of Geobacillus stearothermophilus. 
A)  heat-sensitive tape AND pressure indicators. 
B)  heat-resistant endospores of Geobacillus stearothermophilus. 
C)  pressure indicators AND waiting for contaminants to appear on freshly poured media. 
D)  waiting for contaminants to appear on freshly poured media. 
E)  heat-sensitive tape AND heat-resistant endospores of Geobacillus stearothermophilus.

Question 3

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. 
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.

Question 4

Jasmine tells you she plans to wash her hands with soap and water before working on Paul's boil, to get rid of all the bacteria on her skin and prevent the possibility of Paul getting an infection. You tell her

Accepted Answer

A)  that washing and scrubbing with soap will be fine because the soap will destroy absolutely all of the bacteria on Jasmine's hands. 
B)  that washing and scrubbing with soap is generally sufficient to control microbes in routine situations but that soap itself does not destroy many organisms. Jasmine should try to get some sterile gloves. 
C)  the likely problem is not going to be the bacteria on Jasmine's hands but those on Paul's back. She doesn't need to wash her hands but she should wash Paul's back before she works on his boil. 
D)  that people who are shower regularly are clean and don't have any bacteria on them. Jasmine doesn't need to bother with trying to wash any bacteria off her hands because there won't be any if she showered that day. 
E)  that people have so many bacteria on their skin, it is impossible to remove them. Even washing with soap won't remove any bacteria because they exist in biofilms on the skin. You tell Jasmine that the bacteria are normal microbiota and are harmless. 
A)  that washing and scrubbing with soap will be fine because the soap will destroy absolutely all of the bacteria on Jasmine's hands. 
B)  that washing and scrubbing with soap is generally sufficient to control microbes in routine situations but that soap itself does not destroy many organisms. Jasmine should try to get some sterile gloves. 
C)  the likely problem is not going to be the bacteria on Jasmine's hands but those on Paul's back. She doesn't need to wash her hands but she should wash Paul's back before she works on his boil. 
D)  that people who are shower regularly are clean and don't have any bacteria on them. Jasmine doesn't need to bother with trying to wash any bacteria off her hands because there won't be any if she showered that day. 
E)  that people have so many bacteria on their skin, it is impossible to remove them. Even washing with soap won't remove any bacteria because they exist in biofilms on the skin. You tell Jasmine that the bacteria are normal microbiota and are harmless.

Question 5

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

Accepted Answer

A) True 
 B)False

Question 6

Chlorhexidine

Accepted Answer

A)  is an aldehyde. 
B)  is extensively used in antiseptics. 
C)  is ineffective against vegetative bacteria. 
D)  is limited in use due to its high toxicity. 
E)  commonly causes adverse side effects. 
A)  is an aldehyde. 
B)  is extensively used in antiseptics. 
C)  is ineffective against vegetative bacteria. 
D)  is limited in use due to its high toxicity. 
E)  commonly causes adverse side effects.

Question 7

Pasteurization results in the sterilization of food products.

Accepted Answer

A) True 
 B)False

Question 8

A common application of dry heat in the microbiology laboratory is to

Accepted Answer

A)  prepare specimens for study. 
B)  sterilize media. 
C)  sterilize plastics. 
D)  sterilize the inoculating loop. 
E)  sterilize Petri dishes. 
A)  prepare specimens for study. 
B)  sterilize media. 
C)  sterilize plastics. 
D)  sterilize the inoculating loop. 
E)  sterilize Petri dishes.

Question 9

Microbial death rates may be affected by

Accepted Answer

A)  pH. 
B)  temperature. 
C)  the presence of organics. 
D)  growth in a biofilm. 
E)  All of the answer choices are correct. 
A)  pH. 
B)  temperature. 
C)  the presence of organics. 
D)  growth in a biofilm. 
E)  All of the answer choices are correct.

Question 10

Heat treatment is an effective method for sterilization or disinfection of all materials.

Accepted Answer

A) True 
 B)False

Question 11

Boiling is not reliable for sterilization because

Accepted Answer

A)  heat-sensitive instruments may be destroyed. 
B)  water boils at a higher temperature at lower altitudes. 
C)  heat-resistant endospores are unaffected. 
D)  viruses are more sensitive to heat than bacteria. 
E)  most pathogens are heat stable. 
A)  heat-sensitive instruments may be destroyed. 
B)  water boils at a higher temperature at lower altitudes. 
C)  heat-resistant endospores are unaffected. 
D)  viruses are more sensitive to heat than bacteria. 
E)  most pathogens are heat stable.

Question 12

Please select the INCORRECTLY matched pair.

Accepted Answer

A)  Bacterial endospores - highly resistant. 
B)  D-value - time to destroy 10% of microbes present. 
C)  Critical instrument - scalpels and needles. 
D)  Incineration - burns cells to ashes. 
E)  Sterilants - destroy all microbes including endospores and viruses. 
A)  Bacterial endospores - highly resistant. 
B)  D-value - time to destroy 10% of microbes present. 
C)  Critical instrument - scalpels and needles. 
D)  Incineration - burns cells to ashes. 
E)  Sterilants - destroy all microbes including endospores and viruses.

Question 13

At the end of your conversation with Jasmine, you tell her that the best course of action for her and Paul is to go to the clinic and have the boil treated there. A boil is a serious infection and the risks of trying to treat it at home are just too great.

Accepted Answer

A) True 
 B)False

Question 14

Which of the following is (are) considered when selecting a germicidal chemical?

Accepted Answer

A)  Toxicity AND cost 
B)  Cost AND compatibility with the material being treated 
C)  Compatibility with the material being treated AND environmental impact 
D)  Environmental impact, toxicity AND cost 
E)  All of the answer choices are correct. 
A)  Toxicity AND cost 
B)  Cost AND compatibility with the material being treated 
C)  Compatibility with the material being treated AND environmental impact 
D)  Environmental impact, toxicity AND cost 
E)  All of the answer choices are correct.

Question 15

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. 
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.

Question 16

In a one D process, how many D values would it take to reduce a population of 1010 cells to one survivor?

Accepted Answer

A)  2 
B)  4 
C)  5 
D)  10 
E)  100 
A)  2 
B)  4 
C)  5 
D)  10 
E)  100

Question 17

The most important function of nitrites in processed foods is to

Accepted Answer

A)  prevent browning. 
B)  inhibit the germination of Clostridium botulinum endospores. 
C)  prevent carcinogen formation. 
D)  make the food more acidic. 
E)  destroy cell membranes of potential pathogens. 
A)  prevent browning. 
B)  inhibit the germination of Clostridium botulinum endospores. 
C)  prevent carcinogen formation. 
D)  make the food more acidic. 
E)  destroy cell membranes of potential pathogens.

Question 18

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

Question 19

Ethylene oxide is gas that

Accepted Answer

A)  is very useful for sterilizing heat- or moisture-sensitive items. 
B)  is harmless to people and is safe to use. 
C)  is used as a 37% aqueous solution. 
D)  destroys microbes excluding endospores and viruses. 
E)  reacts with nucleic acids in a cell. 
A)  is very useful for sterilizing heat- or moisture-sensitive items. 
B)  is harmless to people and is safe to use. 
C)  is used as a 37% aqueous solution. 
D)  destroys microbes excluding endospores and viruses. 
E)  reacts with nucleic acids in a cell.

Question 20

Which of the following are resistant to destruction by typical disinfection methods?

Accepted Answer

A)  Endospores of Bacillus and Clostridium 
B)  Escherichia 
C)  Enveloped viruses 
D)  Mycoplasma species 
E)  Vegetative bacteria 
A)  Endospores of Bacillus and Clostridium 
B)  Escherichia 
C)  Enveloped viruses 
D)  Mycoplasma species 
E)  Vegetative bacteria

Exam 5: Control of Microbial Growth

Ultraviolet radiation at the bactericidal wavelength destroys bacteria by

The autoclave treatment may be monitored by

Which is true of iodine?

Jasmine tells you she plans to wash her hands with soap and water before working on Paul's boil, to get rid of all the bacteria on her skin and prevent the possibility of Paul getting an infection. You tell her

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

Chlorhexidine

Pasteurization results in the sterilization of food products.

A common application of dry heat in the microbiology laboratory is to

Microbial death rates may be affected by

Heat treatment is an effective method for sterilization or disinfection of all materials.

Boiling is not reliable for sterilization because

Please select the INCORRECTLY matched pair.

At the end of your conversation with Jasmine, you tell her that the best course of action for her and Paul is to go to the clinic and have the boil treated there. A boil is a serious infection and the risks of trying to treat it at home are just too great.

Which of the following is (are) considered when selecting a germicidal chemical?

Select the FALSE statement regarding hydrogen peroxide.

In a one D process, how many D values would it take to reduce a population of 1010 cells to one survivor?

The most important function of nitrites in processed foods is to

A sterile item is free of

Ethylene oxide is gas that

Which of the following are resistant to destruction by typical disinfection methods?

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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