Question 1

Autoclaving is the most effective method of moist heat sterilization.

Accepted Answer

A) True 
 B)False

Question 2

Disinfection of water is achieved by all of the following EXCEPT

Accepted Answer

A)  UV radiation. 
B)  chlorine. 
C)  peracetic acid. 
D)  copper sulfate. 
E)  ozone. 
A)  UV radiation. 
B)  chlorine. 
C)  peracetic acid. 
D)  copper sulfate. 
E)  ozone.

Question 3

Table 7.3
The following data were obtained by incubating gram- positive bacteria in nutrient medium + disinfectant for 24 hr, then transferring one loopful to nutrient medium (subculturing). (+ = growth; - = no growth)
  
-In Table 7.3, which disinfectant was bactericidal?

Accepted Answer

A)  Doom 
B)  Sterl 
C)  K.O. 
D)  Mortum 
E)  The answer cannot be determined based on the information provided. 
A)  Doom 
B)  Sterl 
C)  K.O. 
D)  Mortum 
E)  The answer cannot be determined based on the information provided.

Question 4

An agent used to reduce the number of bacteria on a toilet would most accurately be called a(n)

Accepted Answer

A)  virucide. 
B)  disinfectant. 
C)  fungicide. 
D)  antiseptic. 
E)  aseptic. 
A)  virucide. 
B)  disinfectant. 
C)  fungicide. 
D)  antiseptic. 
E)  aseptic.

Question 5

The pH of the medium has no effect on the activity of the disinfectant being applied.

Accepted Answer

A) True 
 B)False

Question 6

Which of the following could be used to sterilize plastic Petri plates in a plastic wrapper?

Accepted Answer

A)  ultraviolet radiation 
B)  microwaves 
C)  sunlight 
D)  gamma radiation 
E)  autoclave 
A)  ultraviolet radiation 
B)  microwaves 
C)  sunlight 
D)  gamma radiation 
E)  autoclave

Question 7

The antimicrobial activity of chlorine is due to which of the following?

Accepted Answer

A)  the formation of a hypochlorite ion 
B)  the formation of hydrochloric acid 
C)  disruption of the plasma membrane 
D)  the formation of ozone 
E)  the formation of hypochlorous acid 
A)  the formation of a hypochlorite ion 
B)  the formation of hydrochloric acid 
C)  disruption of the plasma membrane 
D)  the formation of ozone 
E)  the formation of hypochlorous acid

Question 8

Table 7.2
The fate of E. coli O157:H7 in apple cider held at 8°C for 2 weeks, with and without preservatives, is shown below: $\begin{array} { l c } 
& \text { Bacteria/ml } \
\text { Cider only } & 2.2 \
\text { Cider with potassium sorbate } & 2.0 \
\text { Sodium benzoate } & 0 \
\text { Potassium sorbate } + \text { sodium benzoate } &0
\end{array}$
-In Table 7.2, which preservative is most effective?

Accepted Answer

A)  potassium sorbate 
B)  sodium benzoate 
C)  potassium sorbate + sodium benzoate 
D)  no preservative 
A)  potassium sorbate 
B)  sodium benzoate 
C)  potassium sorbate + sodium benzoate 
D)  no preservative

Question 9

Table 7.3
The following data were obtained by incubating gram- positive bacteria in nutrient medium + disinfectant for 24 hr, then transferring one loopful to nutrient medium (subculturing). (+ = growth; - = no growth)
  
-In Table 7.3, which disinfectant was most effective against Salmonella?

Accepted Answer

A)  K.O. 
B)  Sterl 
C)  Doom 
D)  Mortum 
E)  The answer cannot be determined based on the information provided. 
A)  K.O. 
B)  Sterl 
C)  Doom 
D)  Mortum 
E)  The answer cannot be determined based on the information provided.

Question 10

The thermal death time is the time needed to kill all the bacteria in a particular culture at a certain temperature.

Accepted Answer

A) True 
 B)False

Question 11

All of the following substances are effective against nonenveloped viruses EXCEPT

Accepted Answer

A)  chlorine. 
B)  ethylene oxide. 
C)  ozone. 
D)  alcohol. 
E)  None of the answers is correct; all of these are equally effective against nonenveloped viruses. 
A)  chlorine. 
B)  ethylene oxide. 
C)  ozone. 
D)  alcohol. 
E)  None of the answers is correct; all of these are equally effective against nonenveloped viruses.

Question 12

If you were preparing nutrient agar at home and did not have an autoclave, what could you use to sterilize the nutrient agar?

Accepted Answer

A)  boiling for one hour 
B)  hydrogen peroxide 
C)  pressure cooker at 121°C for 15 minutes 
D)  oven at 121°C for one hour 
E)  bleach 
A)  boiling for one hour 
B)  hydrogen peroxide 
C)  pressure cooker at 121°C for 15 minutes 
D)  oven at 121°C for one hour 
E)  bleach

Question 13

Which of the following is a limitation of the autoclave?

Accepted Answer

A)  It cannot be used with glassware. 
B)  It requires an excessively long time to achieve sterilization. 
C)  It cannot kill endospores. 
D)  It cannot inactivate viruses. 
E)  It cannot be used with heat- labile materials. 
A)  It cannot be used with glassware. 
B)  It requires an excessively long time to achieve sterilization. 
C)  It cannot kill endospores. 
D)  It cannot inactivate viruses. 
E)  It cannot be used with heat- labile materials.

Question 14

Which one of the following is most resistant to chemical biocides?

Accepted Answer

A)  gram- negative bacteria 
B)  viruses with lipid envelopes 
C)  protozoan cysts 
D)  mycobacteria 
E)  gram- positive bacteria 
A)  gram- negative bacteria 
B)  viruses with lipid envelopes 
C)  protozoan cysts 
D)  mycobacteria 
E)  gram- positive bacteria

Question 15

Which of the following pairs is mismatched?

Accepted Answer

A)  ultraviolet radiation - desiccation 
B)  supercritical fluids - CO2 
C)  ionizing radiation - hydroxyl radicals 
D)  plasma sterilization - free radicals 
E)  ozone - takes electrons from substances 
A)  ultraviolet radiation - desiccation 
B)  supercritical fluids - CO2 
C)  ionizing radiation - hydroxyl radicals 
D)  plasma sterilization - free radicals 
E)  ozone - takes electrons from substances

Exam 7: The Control of Microbial Growth

Autoclaving is the most effective method of moist heat sterilization.

Disinfection of water is achieved by all of the following EXCEPT

Table 7.3 The following data were obtained by incubating gram- positive bacteria in nutrient medium + disinfectant for 24 hr, then transferring one loopful to nutrient medium (subculturing). (+ = growth; - = no growth) -In Table 7.3, which disinfectant was bactericidal?

An agent used to reduce the number of bacteria on a toilet would most accurately be called a(n)

The pH of the medium has no effect on the activity of the disinfectant being applied.

Which of the following could be used to sterilize plastic Petri plates in a plastic wrapper?

The antimicrobial activity of chlorine is due to which of the following?

Table 7.2 The fate of E. coli O157:H7 in apple cider held at 8°C for 2 weeks, with and without preservatives, is shown below: Bacteria/ml Cider only 2.2 Cider with potassium sorbate 2.0 Sodium benzoate 0 Potassium sorbate + sodium benzoate 0 -In Table 7.2, which preservative is most effective?

Table 7.3 The following data were obtained by incubating gram- positive bacteria in nutrient medium + disinfectant for 24 hr, then transferring one loopful to nutrient medium (subculturing). (+ = growth; - = no growth) -In Table 7.3, which disinfectant was most effective against Salmonella?

The thermal death time is the time needed to kill all the bacteria in a particular culture at a certain temperature.

All of the following substances are effective against nonenveloped viruses EXCEPT

If you were preparing nutrient agar at home and did not have an autoclave, what could you use to sterilize the nutrient agar?

Which of the following is a limitation of the autoclave?

Which one of the following is most resistant to chemical biocides?

Which of the following pairs is mismatched?

The Microbial World and You

Chemical Principles

Observing Microorganisms Through a Microscope

Functional Anatomy of Prokaryotic and Eukaryotic Cells

Microbial Metabolism

Microbial Growth

Microbial Genetics

Biotechnology and Recombinant Dna

Classification of Microorganisms

The Prokaryotes: Domains Bacteria and Archaea

The Eukaryotes: Fungi, Algae, Protozoa, and Helminths

Viruses, Viroids, and Prions

Principles of Disease and Epidemiology

Microbial Mechanisms of Pathogenicity

Innate Immunity: Nonspecific Defenses of the Host

Adaptive Immunity: Specific Defenses of the Host

Practical Applications of Immunology

Disorders Associated With the Immune System

Antimicrobial Drugs

Microbial Diseases of the Skin and Eyes

Microbial Diseases of the Nervous System

Microbial Diseases of the Cardiovascular and Lymphatic Systems

Microbial Diseases of the Respiratory System

Microbial Diseases of the Digestive System

Microbial Diseases of the Urinary and Reproductive Systems

Environmental Microbiology

Applied and Industrial Microbiology

Filters