Question 1

An iodophor is a(n)

Accepted Answer

A)  iodine mixed with a surfactant. 
B)  agent that reduces oxygen. 
C)  quaternary ammonium compound. 
D)  form of formaldehyde. 
E)  phenol. 
A)  iodine mixed with a surfactant. 
B)  agent that reduces oxygen. 
C)  quaternary ammonium compound. 
D)  form of formaldehyde. 
E)  phenol.

Question 2

Desiccation is a reliable form of sterilization.

Accepted Answer

A) True 
 B)False

Question 3

Why must most milk sold in the U.S. be refrigerated at all times while evaporated canned milk and milk in cardboard containers sold in Europe do not need to be refrigerated until they are opened?

Accepted Answer

The primary reason most milk sold in the

Question 4

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 $/ \mathrm { ml }$
$\begin{array}{ll}
\text { Cider only } & 2.2 \
\text { Cider with potassium sorbate } & 2.0 \
\text { Sodium benzoate } & 0 \
\text { Potassium sorbate + sodium benzoate } & 0
\end{array}$ In Table 7.2, which preservative is most effective?

Accepted Answer

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

Question 5

All of the following are effective for destroying prions EXCEPT

Accepted Answer

A)  boiling. 
B)  NaOH + autoclaving at 134°C. 
C)  proteases. 
D)  incineration. 
E)  None of the answers are correct; each of these will destroy prions. 
A)  boiling. 
B)  NaOH + autoclaving at 134°C. 
C)  proteases. 
D)  incineration. 
E)  None of the answers are correct; each of these will destroy prions.

Question 6

Which of the following is a limitation of the autoclave?

Accepted Answer

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

Question 7

Moist heat destroys organisms by denaturing proteins.

Accepted Answer

A) True 
 B)False

Question 8

Application of heat to living cells can result in all of the following EXCEPT

Accepted Answer

A)  decreased thermal death time. 
B)  alteration of membrane permeability. 
C)  damage to nucleic acids. 
D)  breaking of hydrogen bonds. 
E)  denaturation of enzymes. 
A)  decreased thermal death time. 
B)  alteration of membrane permeability. 
C)  damage to nucleic acids. 
D)  breaking of hydrogen bonds. 
E)  denaturation of enzymes.

Question 9

Ultraviolet light (UV) causes irreversible breaks in DNA strands.

Accepted Answer

A) True 
 B)False

Question 10

Figure 7.1
   A suspension of 106 Bacillus cereus endospores was put in a hot-air oven at 170°C. Plate counts were used to determine the number of endospores surviving at the time intervals shown.
-Which of the following pairs is mismatched?

Accepted Answer

A)  organic acids  food preservation 
B)  Ag  wound dressings 
C)  alcohols  open wounds 
D)  CuSO4  algicide 
E)  H2o2  open wounds 
A)  organic acids  food preservation 
B)  Ag  wound dressings 
C)  alcohols  open wounds 
D)  CuSO4  algicide 
E)  H2o2  open wounds

Question 11

All of the following are methods of food preservation EXCEPT

Accepted Answer

A)  ionizing radiation. 
B)  high pressure. 
C)  osmotic pressure. 
D)  microwaves. 
E)  desiccation. 
A)  ionizing radiation. 
B)  high pressure. 
C)  osmotic pressure. 
D)  microwaves. 
E)  desiccation.

Question 12

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

Accepted Answer

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

Question 13

What are the advantages of gluteraldehyde compared to formaldehyde?

Accepted Answer

Glutaraldehyde and formaldehyde are both

Question 14

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

Question 15

Figure 7.2
Assume 109 E. coli cells/ml are in a flask.
  
-Which graph in Figure 7.2 best depicts the effect of placing the culture in an autoclave for 15 minutes at time x?

Accepted Answer

A)  a 
B)  b 
C)  c 
D)  d 
E)  e 
A)  a 
B)  b 
C)  c 
D)  d 
E)  e

Question 16

Which of the following pairs of terms is mismatched?

Accepted Answer

A)  fungicide  kills yeasts and molds 
B)  bacteriostatic  kills vegetative bacterial cells 
C)  sterilant  destroys all living microorganisms 
D)  virucide  inactivates viruses 
E)  germicide  kills microbes 
A)  fungicide  kills yeasts and molds 
B)  bacteriostatic  kills vegetative bacterial cells 
C)  sterilant  destroys all living microorganisms 
D)  virucide  inactivates viruses 
E)  germicide  kills microbes

Question 17

Which of the following substances is used for surgical hand scrubs?

Accepted Answer

A)  phenol 
B)  glutaraldehyde 
C)  chlorine bleach 
D)  soap 
E)  chlorhexidine 
A)  phenol 
B)  glutaraldehyde 
C)  chlorine bleach 
D)  soap 
E)  chlorhexidine

Question 18

How is hydrogen peroxide antimicrobial?

Accepted Answer

Hydrogen peroxide (H2O2) is a powerful o

Question 19

Any process that destroys the non-spore forming contaminants on inanimate objects is sterilization.

Accepted Answer

A) True 
 B)False

Question 20

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

Exam 7: The Control of Microbial Growth

An iodophor is a(n)

Desiccation is a reliable form of sterilization.

Why must most milk sold in the U.S. be refrigerated at all times while evaporated canned milk and milk in cardboard containers sold in Europe do not need to be refrigerated until they are opened?

All of the following are effective for destroying prions EXCEPT

Which of the following is a limitation of the autoclave?

Moist heat destroys organisms by denaturing proteins.

Application of heat to living cells can result in all of the following EXCEPT

Ultraviolet light (UV) causes irreversible breaks in DNA strands.

Figure 7.1 A suspension of 106 Bacillus cereus endospores was put in a hot-air oven at 170°C. Plate counts were used to determine the number of endospores surviving at the time intervals shown. -Which of the following pairs is mismatched?

All of the following are methods of food preservation EXCEPT

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

What are the advantages of gluteraldehyde compared to formaldehyde?

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

Figure 7.2 Assume 109 E. coli cells/ml are in a flask. -Which graph in Figure 7.2 best depicts the effect of placing the culture in an autoclave for 15 minutes at time x?

Which of the following pairs of terms is mismatched?

Which of the following substances is used for surgical hand scrubs?

How is hydrogen peroxide antimicrobial?

Any process that destroys the non-spore forming contaminants on inanimate objects is sterilization.

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

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 Dna Technology

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 Disease of the Urinary and Reproductive Systems

Environmental Microbiology

Applied and Industrial Microbiology

Filters