Question 1

Alcohols are not reliably effective at destroying

Accepted Answer

A)  vegetative bacteria. 
B)  enveloped viruses. 
C)  naked viruses. 
D)  endospores. 
E)  naked viruses AND endospores. 
A)  vegetative bacteria. 
B)  enveloped viruses. 
C)  naked viruses. 
D)  endospores. 
E)  naked viruses AND endospores. E

Question 2

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

Accepted Answer

A) True 
 B)False  False

Question 3

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 
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 A

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. 
A)  all die immediately. 
B)  die at a constant proportion. 
C)  die at an exponential rate. 
D)  die at a geometric rate.

Question 5

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

Accepted Answer

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

Question 6

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

Question 7

Generally, membrane filters are not used to remove

Accepted Answer

A)  bacteria from liquids. 
B)  microorganisms from gases. 
C)  spoilage agents from alcoholic beverages. 
D)  enzymes. 
A)  bacteria from liquids. 
B)  microorganisms from gases. 
C)  spoilage agents from alcoholic beverages. 
D)  enzymes.

Question 8

Compounds of tin, mercury, arsenic, and copper are no longer used to prevent microbial growth in cooling water primarily because

Accepted Answer

A)  antibiotics are cheaper. 
B)  other chemicals were shown to be much more effective. 
C)  microbes developed resistance to these metals. 
D)  their use contributes to serious pollution of natural waters. 
E)  All of the choices are correct. 
A)  antibiotics are cheaper. 
B)  other chemicals were shown to be much more effective. 
C)  microbes developed resistance to these metals. 
D)  their use contributes to serious pollution of natural waters. 
E)  All of the choices are correct.

Question 9

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

Accepted Answer

A) True 
 B)False

Question 10

Ultraviolet radiation at the bactericidal wavelength destroy bacteria by

Accepted Answer

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

Question 11

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. 
A)  the heat they generate in a product. 
B)  generating free radicals. 
C)  generating toxins. 
D)  creating thymine dimers.

Question 12

Glutaraldehyde

Accepted Answer

A)  is, if given enough time, able to destroy all forms of microbial life. 
B)  is very good for use on heat-sensitive medical items. 
C)  attacks lipids. 
D)  does not affect naked viruses. 
E)  is, if given enough time, able to destroy all forms of microbial life AND is very good for use on heat-sensitive medical items. 
A)  is, if given enough time, able to destroy all forms of microbial life. 
B)  is very good for use on heat-sensitive medical items. 
C)  attacks lipids. 
D)  does not affect naked viruses. 
E)  is, if given enough time, able to destroy all forms of microbial life AND is very good for use on heat-sensitive medical items.

Question 13

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. 
A)  by moist heat. 
B)  by moist heat under pressure. 
C)  in a hot air oven. 
D)  in the presence of organics.

Question 14

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

Accepted Answer

A)  toxicity 
B)  cost 
C)  compatibility with the material being treated 
D)  environmental impact 
E)  All of the choices are correct. 
A)  toxicity 
B)  cost 
C)  compatibility with the material being treated 
D)  environmental impact 
E)  All of the choices are correct.

Question 15

Boiling is not reliable for sterilization because

Accepted Answer

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

Question 16

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. 
A)  prevent browning. 
B)  inhibit the germination of Clostridium botulinum endospores. 
C)  prevent carcinogen formation. 
D)  make the food more acidic.

Question 17

Prions and viroids are easily destroyed by common sterilization procedures.

Accepted Answer

A) True 
 B)False

Question 18

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

Accepted Answer

A)  sterilization. 
B)  disinfection. 
C)  sanitation. 
D)  antisepsis. 
A)  sterilization. 
B)  disinfection. 
C)  sanitation. 
D)  antisepsis.

Question 19

Chlorhexidine

Accepted Answer

A)  is a member of the biguanides. 
B)  is extensively used in antiseptics. 
C)  is ineffective against vegetative bacteria. 
D)  is limited in use due to its high toxicity. 
E)  is a member of the biguanides AND is extensively used in antiseptics. 
A)  is a member of the biguanides. 
B)  is extensively used in antiseptics. 
C)  is ineffective against vegetative bacteria. 
D)  is limited in use due to its high toxicity. 
E)  is a member of the biguanides AND is extensively used in antiseptics.

Question 20

A sterile item is free of

Accepted Answer

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

Exam 5: Control of Microbial Growth

Alcohols are not reliably effective at destroying

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

Which are essentially equivalent treatments?

Upon treatment with heat or chemicals, bacteria will

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

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

Generally, membrane filters are not used to remove

Compounds of tin, mercury, arsenic, and copper are no longer used to prevent microbial growth in cooling water primarily because

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

Ultraviolet radiation at the bactericidal wavelength destroy bacteria by

Microwaves do not kill organisms directly but kill by

Glutaraldehyde

Oxidation of proteins is achieved most readily

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

Boiling is not reliable for sterilization because

The most important function of nitrites in processed foods is to

Prions and viroids are easily destroyed by common sterilization procedures.

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

Chlorhexidine

A sterile item is free of

Humans and the Microbial World

The Molecules of Life

Microscopy and Cell Structure

Dynamics of Prokaryotic Growth

Metabolism: Fueling Cell Growth

The Blueprint of Life, From Dna to Protein

Bacterial Genetics

Biotechnology and Recombinant Dna

Identification and Classification of Prokaryotes

The Diversity of Prokaryotic Organisms

The Eukaryotic Members of the Microbial World

Viruses, Viroids and Prions

The Innate Immune Response

The Adaptive Immune Response

Host-Microbe Interactions

Immunologic Disorders

Applications of Immune Responses

Epidemiology

Antimicrobial Medications

Respiratory System Infections

Skin Infections

Wound Infections

Digestive System Infections

Genitourinary Infections

Nervous System Infections

Blood and Lymphatic Infections

Hiv Disease and Complications of Immunodeficiency

Microbial Ecology

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

Food Microbiology

Filters

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