Question 1

Soaps and detergents are very effective as sterilants.

Accepted Answer

A) True 
 B)False

Question 2

Your aim is to sterilize prosthetic devices like heart valves and artificial joint structures before being used in the patient.Considering where they will be placed and the probable composition of the devices,what would be the best chemical to use?

Accepted Answer

A)  Crystal violet dye 
B)  Iodine 
C)  Quaternary ammonium compounds 
D)  Bleach 
A)  Crystal violet dye 
B)  Iodine 
C)  Quaternary ammonium compounds 
D)  Bleach

Question 3

Which of the following is an advantage to using phenolics as antimicrobial agents?

Accepted Answer

A)  The presence of organic matter does not limit its antimicrobial qualities. 
B)  They are not susceptible to resistance by organisms. 
C)  They have low toxicity. 
D)  They are effective sterilants against all microbial forms. 
A)  The presence of organic matter does not limit its antimicrobial qualities. 
B)  They are not susceptible to resistance by organisms. 
C)  They have low toxicity. 
D)  They are effective sterilants against all microbial forms.

Question 4

Endospores can be inactivated by

Accepted Answer

A)  dry heat at 170°C for 2 hours. 
B)  incineration. 
C)  glutaraldehyde for 3 or more hours. 
D)  ethylene oxide for 3 or more hours. 
E)  All of the choices are correct. 
A)  dry heat at 170°C for 2 hours. 
B)  incineration. 
C)  glutaraldehyde for 3 or more hours. 
D)  ethylene oxide for 3 or more hours. 
E)  All of the choices are correct.

Question 5

Which of the following germicides is/are also sporicidal?

Accepted Answer

A)  Betadine 
B)  Chlorine 
C)  Phenolics 
D)  Chlorhexidine 
E)  All of these except phenolics. 
A)  Betadine 
B)  Chlorine 
C)  Phenolics 
D)  Chlorhexidine 
E)  All of these except phenolics.

Question 6

All microbicidal agents are sterilants.

Accepted Answer

A) True 
 B)False

Question 7

Some microbial control agents are able to _____ cell proteins by breaking bonds that maintain the native state,the three-dimensional configuration of the proteins.

Accepted Answer

A)  mutate 
B)  bind 
C)  dissolve 
D)  denature 
A)  mutate 
B)  bind 
C)  dissolve 
D)  denature

Question 8

Which of the following is true regarding the use of osmotic pressure as an antimicrobial agent?

Accepted Answer

A)  Salts and sugars external to a microbe create a hypotonic environment, which causes lysis of the cell. 
B)  Salt is an effective solute to create an osmotic pressure gradient outside of a cell; however, the use of sugar, such as in jams and jellies, works via a different mechanism. 
C)  Exposing a microbe to a hypertonic environment draws water out of the cell, causing plasmolysis. 
D)  Exposing organisms to the air on a benchtop so they completely dry out is an example of using osmotic pressure as a means of microbial control. 
A)  Salts and sugars external to a microbe create a hypotonic environment, which causes lysis of the cell. 
B)  Salt is an effective solute to create an osmotic pressure gradient outside of a cell; however, the use of sugar, such as in jams and jellies, works via a different mechanism. 
C)  Exposing a microbe to a hypertonic environment draws water out of the cell, causing plasmolysis. 
D)  Exposing organisms to the air on a benchtop so they completely dry out is an example of using osmotic pressure as a means of microbial control.

Question 9

What instrument is most effective for pressure-temperature sterilization?

Accepted Answer

A)  Water-bath 
B)  Autoclave 
C)  Incubator 
D)  Oven 
E)  Bunsen burner 
A)  Water-bath 
B)  Autoclave 
C)  Incubator 
D)  Oven 
E)  Bunsen burner

Question 10

All of the following are phenols or phenolics except ______.

Accepted Answer

A)  hexachlorophene 
B)  Zephiran 
C)  cresols 
D)  triclosan 
E)  Lysol 
A)  hexachlorophene 
B)  Zephiran 
C)  cresols 
D)  triclosan 
E)  Lysol

Question 11

Which control method would not be a suitable choice for killing Mycobacterium in a capped culture tube?

Accepted Answer

A)  Ultraviolet (germicidal) light 
B)  Gamma rays 
C)  121°C at 15 psi for 15 minutes 
D)  160°C for 2 hours 
E)  All of the choices are correct. 
A)  Ultraviolet (germicidal) light 
B)  Gamma rays 
C)  121°C at 15 psi for 15 minutes 
D)  160°C for 2 hours 
E)  All of the choices are correct.

Question 12

Hydrogen peroxide is

Accepted Answer

A)  sporicidal. 
B)  fungicidal. 
C)  bactericidal. 
D)  virucidal. 
E)  All of the choices are correct. 
A)  sporicidal. 
B)  fungicidal. 
C)  bactericidal. 
D)  virucidal. 
E)  All of the choices are correct.

Question 13

_____ heat is more rapidly effective and efficient compared to _____ heat.

Accepted Answer

A)  High; dry 
B)  High; moist 
C)  Dry; moist 
D)  Moist; dry 
E)  Moist; high 
A)  High; dry 
B)  High; moist 
C)  Dry; moist 
D)  Moist; dry 
E)  Moist; high

Question 14

Your friend Joe recently visited the doctor for steroid injections into his knee to reduce swelling due to a previous knee injury.Within a couple of days,he had an infection caused by Pseudomonas,a very pathogenic and drug resistant bacterium.Luckily,Joe went to the doctor immediately and received antibiotics.The doctor tells him that the same problem has occurred to many other people across the United States.Predict the most likely cause of this situation.

Accepted Answer

A)  The steroid was contaminated at the production plant, so all batches of that drug made at that plant were contaminated with the bacterium. 
B)  The bacterium is normally on the skin of people, so can easily access the patient's blood during the needle stick. 
C)  The staff giving the steroid injections did not use proper aseptic technique. 
D)  The needles were re-used and already contaminated before being used on the patients. 
A)  The steroid was contaminated at the production plant, so all batches of that drug made at that plant were contaminated with the bacterium. 
B)  The bacterium is normally on the skin of people, so can easily access the patient's blood during the needle stick. 
C)  The staff giving the steroid injections did not use proper aseptic technique. 
D)  The needles were re-used and already contaminated before being used on the patients.

Question 15

Antimicrobial agents can target the cell wall by

Accepted Answer

A)  blocking its synthesis. 
B)  digesting it. 
C)  denaturing proteins. 
D)  All of the choices are correct. 
A)  blocking its synthesis. 
B)  digesting it. 
C)  denaturing proteins. 
D)  All of the choices are correct.

Question 16

The compound that is an organic base containing chlorine and two phenolic rings,and is used increasingly for wound degerming,neonatal washes,hand scrubbing,and prepping surgical skin sites is ______.

Accepted Answer

A)  a quaternary ammonium compound 
B)  carbolic acid 
C)  triclosan 
D)  formalin 
E)  chlorhexidine 
A)  a quaternary ammonium compound 
B)  carbolic acid 
C)  triclosan 
D)  formalin 
E)  chlorhexidine

Question 17

You have some old plastic Petri dishes that you would like to use for pouring bacteriological agar plates.The only method of physical sterilization is ultraviolet radiation sterilization with your UV light (you cannot use the autoclave because it will disfigure and melt the plastic).After sterilizing the plates,pouring the sterilized agar medium,and then leaving the plates out at room temperature for a day or two to let them solidify and dry,you find contaminating bacterial colonies growing on the agar.Predict what has happened in this situation.

Accepted Answer

A)  The room temperature enhanced the growth of normal biota of the agar. 
B)  Air got into the poured agar plates, contaminating them. 
C)  The lids of the Petri dishes were inadvertently left on while being sterilized. 
D)  The agar had bacteria in it, even after sterilization in the autoclave. 
A)  The room temperature enhanced the growth of normal biota of the agar. 
B)  Air got into the poured agar plates, contaminating them. 
C)  The lids of the Petri dishes were inadvertently left on while being sterilized. 
D)  The agar had bacteria in it, even after sterilization in the autoclave.

Question 18

Which of the following is not used as an antiseptic?

Accepted Answer

A)  Iodophor 
B)  Aqueous glutaraldehyde 
C)  3% hydrogen peroxide 
D)  Chlorhexidine 
E)  Merthiolate 
A)  Iodophor 
B)  Aqueous glutaraldehyde 
C)  3% hydrogen peroxide 
D)  Chlorhexidine 
E)  Merthiolate

Question 19

In lab,inoculating loops are sterilized using ______.

Accepted Answer

A)  chemicals 
B)  incineration 
C)  filtration 
D)  moist heat 
E)  gas sterilization 
A)  chemicals 
B)  incineration 
C)  filtration 
D)  moist heat 
E)  gas sterilization

Question 20

The shortest time required to kill or inactivate all the microbes in a sample at a specified temperature is called the

Accepted Answer

A)  thermal death point (TDP). 
B)  thermal death time (TDT). 
C)  sporicidal time. 
D)  death phase point. 
A)  thermal death point (TDP). 
B)  thermal death time (TDT). 
C)  sporicidal time. 
D)  death phase point.

Exam 11: Physical and Chemical Control of Microbes

Soaps and detergents are very effective as sterilants.

Your aim is to sterilize prosthetic devices like heart valves and artificial joint structures before being used in the patient.Considering where they will be placed and the probable composition of the devices,what would be the best chemical to use?

Which of the following is an advantage to using phenolics as antimicrobial agents?

Endospores can be inactivated by

Which of the following germicides is/are also sporicidal?

All microbicidal agents are sterilants.

Some microbial control agents are able to _____ cell proteins by breaking bonds that maintain the native state,the three-dimensional configuration of the proteins.

Which of the following is true regarding the use of osmotic pressure as an antimicrobial agent?

What instrument is most effective for pressure-temperature sterilization?

All of the following are phenols or phenolics except ______.

Which control method would not be a suitable choice for killing Mycobacterium in a capped culture tube?

Hydrogen peroxide is

_____ heat is more rapidly effective and efficient compared to _____ heat.

Antimicrobial agents can target the cell wall by

The compound that is an organic base containing chlorine and two phenolic rings,and is used increasingly for wound degerming,neonatal washes,hand scrubbing,and prepping surgical skin sites is ______.

Which of the following is not used as an antiseptic?

In lab,inoculating loops are sterilized using ______.

The shortest time required to kill or inactivate all the microbes in a sample at a specified temperature is called the

The Main Themes of Microbiology

The Chemistry of Biology

Tools of the Laboratory: Methods for the Culturing of Microscopic Analysis of Microorganisms

Bacteria and Archaea

Eukaryotic Cells and Microorganisms

An Introduction to the Viruses

Host Defenses II: Specific Immunity and Immunization

Microbial Metabolism: The Chemical Crossroads of Life

Microbial Genetics

Genetic Engineering and Recombinant Dna

Antimicrobial Treatment

Microbe-Human Interactions: Health and Disease

Host Defenses I: Overview and Nonspecific Defenses

Host Defenses II: Specific Immunity and Immunization

Disorders in Immunity

Diagnosing Infections

Infectious Diseases Affecting the Skin and Eyes

Infectious Diseases Affecting the Nervous System

Infectious Diseases Affecting the Cardiovascular and Lymphatic Systems

Infectious Diseases Affecting the Respiratory System

Infectious Diseases Affecting the Gastrointestinal Tract

Infectious Diseases Affecting the Genitourinary System

Microbes and the Environment

Applied Microbiology and Food and Water Safety

Filters

_ heat is more rapidly effective and efficient compared to _ heat.