Question 1

Moist heat destroys organisms by denaturing proteins.

Accepted Answer

A) True 
 B)False

Question 2

Bone and tendons for transplant are decontaminated by

Accepted Answer

A)  ethylene oxide. 
B)  plasma sterilization. 
C)  glutaraldehyde. 
D)  supercritical fluids. 
E)  peroxygens. 
A)  ethylene oxide. 
B)  plasma sterilization. 
C)  glutaraldehyde. 
D)  supercritical fluids. 
E)  peroxygens.

Question 3

Which of the following results in lethal damage to nucleic acids?

Accepted Answer

A)  heat 
B)  radiation 
C)  certain chemicals 
D)  heat and radiation 
E)  heat, radiation, and some chemicals 
A)  heat 
B)  radiation 
C)  certain chemicals 
D)  heat and radiation 
E)  heat, radiation, and some chemicals

Question 4

Table 7.5
The following results were obtained from a use- dilution test of two disinfectants.
Cultures were inoculated into tubes containing varying concentrations of the disinfectants, incubated for 10 min. at 20°C, and then transferred to growth media without disinfectant. (+ = growth; - = no growth)
  
-In Table 7.5, which disinfectant is most effective? Against which group of bacteria is Disinfectant A most effective?

Accepted Answer

Without the specific data from Table 7.5

Question 5

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

Accepted Answer

A) True 
 B)False

Question 6

Which of the following regarding antimicrobial control agents is FALSE?

Accepted Answer

A)  Contaminating organic debris such as blood or sputum decrease effectiveness. 
B)  Some agents inactivate viruses by attacking cell membrane lipids. 
C)  Some agents affect microbial cell membranes by dissolving lipids. 
D)  Some agents kill by denaturing microbial cell proteins. 
E)  Silver is used for treating antibiotic- resistant bacteria. 
A)  Contaminating organic debris such as blood or sputum decrease effectiveness. 
B)  Some agents inactivate viruses by attacking cell membrane lipids. 
C)  Some agents affect microbial cell membranes by dissolving lipids. 
D)  Some agents kill by denaturing microbial cell proteins. 
E)  Silver is used for treating antibiotic- resistant bacteria.

Question 7

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

Accepted Answer

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

Question 8

The preservation of beef jerky from microbial growth relies on which method of microbial control?

Accepted Answer

A)  ionizing radiation 
B)  filtration 
C)  lyophilization 
D)  desiccation 
E)  supercritical CO2 
A)  ionizing radiation 
B)  filtration 
C)  lyophilization 
D)  desiccation 
E)  supercritical CO2

Question 9

Which of the following pairs of terms is mismatched?

Accepted Answer

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

Question 10

Which of the following chemical agents is used for sterilization?

Accepted Answer

A)  alcohol 
B)  phenolics 
C)  soap 
D)  chlorine 
E)  ethylene oxide 
A)  alcohol 
B)  phenolics 
C)  soap 
D)  chlorine 
E)  ethylene oxide

Question 11

Microorganisms placed in high concentrations of salts and sugars undergo lysis.

Accepted Answer

A) True 
 B)False

Question 12

Some antimicrobial chemicals are considered to be disinfectants and antiseptics.

Accepted Answer

A) True 
 B)False

Question 13

Figure 7.1
A suspension of 10S1U1P16S1S1P0S1U1P1 S1S1P0Bacillus 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.
  
-In Figure 7.1, the decimal reduction time (D value) for the culture is approximately

Accepted Answer

A)  0 minutes. 
B)  10 minutes. 
C)  30 minutes. 
D)  40 minutes. 
E)  60 minutes. 
A)  0 minutes. 
B)  10 minutes. 
C)  30 minutes. 
D)  40 minutes. 
E)  60 minutes.

Question 14

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 is the most effective at stopping bacterial growth?

Accepted Answer

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

Question 15

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 16

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

Accepted Answer

A) True 
 B)False

Question 17

Which of the following regarding antimicrobial control agents is FALSE?

Accepted Answer

A)  Some agents are utilized as both an antiseptic and a disinfectant. 
B)  A true antimicrobial control agent is equally effective against both bacteria and viruses. 
C)  Contaminating organic debris such as blood or sputum will decrease effectiveness. 
D)  Some agents kill by denaturing microbial cell proteins. 
E)  Some agents affect microbial cell membranes by dissolving lipids. 
A)  Some agents are utilized as both an antiseptic and a disinfectant. 
B)  A true antimicrobial control agent is equally effective against both bacteria and viruses. 
C)  Contaminating organic debris such as blood or sputum will decrease effectiveness. 
D)  Some agents kill by denaturing microbial cell proteins. 
E)  Some agents affect microbial cell membranes by dissolving lipids.

Question 18

Which of the following methods is used to preserve food by slowing the metabolic processes of foodborne microbes?

Accepted Answer

A)  ionizing radiation 
B)  nonionizing radiation 
C)  lyophilization 
D)  pasteurization 
E)  freezing 
A)  ionizing radiation 
B)  nonionizing radiation 
C)  lyophilization 
D)  pasteurization 
E)  freezing

Question 19

Pseudomonas has been found growing in quaternary ammonium compounds (quats).

Accepted Answer

A) True 
 B)False

Question 20

All of the following substances are used to preserve foods EXCEPT

Accepted Answer

A)  potassium sorbate. 
B)  biguanides. 
C)  sodium nitrite. 
D)  calcium propionate. 
E)  nisin. 
A)  potassium sorbate. 
B)  biguanides. 
C)  sodium nitrite. 
D)  calcium propionate. 
E)  nisin.

Exam 7: The Control of Microbial Growth

Moist heat destroys organisms by denaturing proteins.

Bone and tendons for transplant are decontaminated by

Which of the following results in lethal damage to nucleic acids?

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

Which of the following regarding antimicrobial control agents is FALSE?

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

The preservation of beef jerky from microbial growth relies on which method of microbial control?

Which of the following pairs of terms is mismatched?

Which of the following chemical agents is used for sterilization?

Microorganisms placed in high concentrations of salts and sugars undergo lysis.

Some antimicrobial chemicals are considered to be disinfectants and antiseptics.

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. -In Figure 7.1, the decimal reduction time (D value) for the culture is approximately

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?

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

Which of the following regarding antimicrobial control agents is FALSE?

Which of the following methods is used to preserve food by slowing the metabolic processes of foodborne microbes?

Pseudomonas has been found growing in quaternary ammonium compounds (quats).

All of the following substances are used to preserve foods EXCEPT

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

Figure 7.1 A suspension of 10⁶Bacillus 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. -In Figure 7.1, the decimal reduction time (D value) for the culture is approximately