Question 1

The lowest temperature that kills all cells in a broth in 10 minutes is known as the (microbial/thermal) death point.

Accepted Answer

thermal

Question 2

Which of the following statements about aldehydes is FALSE?

Accepted Answer

A)  They are used in aqueous solutions. 
B)  They are used only to preserve dead tissues. 
C)  They are usually hazardous to humans. 
D)  They denature proteins. 
E)  Some aldehydes can sterilize after long periods of exposure. 
A)  They are used in aqueous solutions. 
B)  They are used only to preserve dead tissues. 
C)  They are usually hazardous to humans. 
D)  They denature proteins. 
E)  Some aldehydes can sterilize after long periods of exposure. B

Question 3

A student is shopping for antibacterial hand cleansers and is trying to decide which one to buy. One is a "waterless" hand gel containing 70% isopropanol, the second is an "antibacterial" hand soap containing triclosan (a phenolic), and the third is a wipe that lists benzethonium chloride (a synthetic quaternary ammonium salt) as the active ingredient. Compare and contrast these cleansers in terms of the action of the antimicrobial ingredient and the level of disinfection (degerming, germistatic, germicidal).

Accepted Answer

All three are germicidal, although not all to the same degree. The alcohol of the waterless hand cleaner is a germicide that disrupts cytoplasmic membranes and denatures proteins. It is not effective against bacterial endospores or fungal spores, and it has limited effect on nonenveloped viruses. The alcohol evaporates quickly, so the germicidal effect is short term. The waterless hand cleaner is an
intermediate- level disinfectant and is not an effective degermer. The hand soap contains a phenolic, which also damages cytoplasmic membranes and denatures proteins, and is effective on the same range of microbes as the alcohol. Phenolics are intermediate- level disinfectants that persist on surfaces for long periods of time, providing extended disinfection. If used with running water and the hands are vigorously rubbed, the hand soap can be an effective degermer. Synthetic "quats" (quaternary ammonium compounds) disrupt cell membranes. They are effective against fungi, enveloped viruses, and most bacteria, but not against nonenveloped viruses, nor on endospores. Quats are low- level disinfectants that are germicidal for some microbes. The action of using and discarding the wipe provides some degerming effect.

Question 4

Elements such as iodine, chlorine, and bromine are examples of (oxidizers/halogens/metals), which are the basis for many effective antimicrobial agents.

Accepted Answer

The answer of Elements such as iodine, chlorine, and bromine...

Question 5

Seventy percent alcohol is effective against

Accepted Answer

A)  bacterial endospores. 
B)  enveloped viruses. 
C)  prions. 
D)  nonenveloped viruses. 
E)  protozoan cysts. 
A)  bacterial endospores. 
B)  enveloped viruses. 
C)  prions. 
D)  nonenveloped viruses. 
E)  protozoan cysts.

Question 6

By themselves, soaps have only degerming activity, not antimicrobial activity.

Accepted Answer

A) True 
 B)False

Question 7

A(n) (iodophor/halogen) is an iodine- containing organic compound found in such antiseptics as Betadine.

Accepted Answer

The answer of A(n) (iodophor/halogen) is an iodine- containing organic...

Question 8

Ultraviolet light penetrates (more/less) effectively than gamma rays.

Accepted Answer

The answer of Ultraviolet light penetrates (more/less) effectively than gamma...

Question 9

The dairy creamer used in restaurants is usually treated by

Accepted Answer

A)  ionizing radiation. 
B)  filtration. 
C)  lyophilization. 
D)  ultra- high- temperature pasteurization. 
E)  autoclaving. 
A)  ionizing radiation. 
B)  filtration. 
C)  lyophilization. 
D)  ultra- high- temperature pasteurization. 
E)  autoclaving.

Question 10

The process of freeze- drying microbes to preserve them is (lyophilization/dessication).

Accepted Answer

The answer of The process of freeze- drying microbes to...

Question 11

Compare and contrast the nine major types of antimicrobial chemicals in terms of their effective on microbes.

Accepted Answer

Alcohols disrupt lipid membranes and den

Question 12

Disinfectants known as (alcohols/oxidizers/aldehydes) have the chemical group - CHO, which reacts with and damages both proteins and nucleic acids.

Accepted Answer

The answer of Disinfectants known as (alcohols/oxidizers/aldehydes) have the chemical...

Question 13

The phenol coefficient is one of the most widely used measurements of an antimicrobial agent's effectiveness.

Accepted Answer

A) True 
 B)False

Question 14

Aseptic means

Accepted Answer

A)  sanitized. 
B)  free of all microbes. 
C)  clean. 
D)  sterile. 
E)  free of pathogens. 
A)  sanitized. 
B)  free of all microbes. 
C)  clean. 
D)  sterile. 
E)  free of pathogens.

Question 15

Disinfectants that damage membranes include

Accepted Answer

A)  hydrogen peroxide. 
B)  phenolics. 
C)  iodine. 
D)  alcohol. 
E)  both alcohol and phenolics. 
A)  hydrogen peroxide. 
B)  phenolics. 
C)  iodine. 
D)  alcohol. 
E)  both alcohol and phenolics.

Question 16

Some viruses are inactivated by the same chemical or physical agents that damage cytoplasmic membranes.

Accepted Answer

A) True 
 B)False

Question 17

A chemical agent that kills pathogenic microbes in general is a(n)

Accepted Answer

A)  antiseptic. 
B)  disinfectant. 
C)  fungicide. 
D)  sanitizer. 
E)  germicide. 
A)  antiseptic. 
B)  disinfectant. 
C)  fungicide. 
D)  sanitizer. 
E)  germicide.

Question 18

Which of the following statements about quaternary ammonium compounds is FALSE?

Accepted Answer

A)  They function by cross- linking proteins. 
B)  They are a type of detergent. 
C)  Zephiran is an example of a quat. 
D)  They are harmless to humans except at high concentrations. 
E)  They are not effective against Pseudomonas aeruginosa. 
A)  They function by cross- linking proteins. 
B)  They are a type of detergent. 
C)  Zephiran is an example of a quat. 
D)  They are harmless to humans except at high concentrations. 
E)  They are not effective against Pseudomonas aeruginosa.

Question 19

The deadliest, most contagious microbes are studied under conditions of (BSL- 4/BSL- 3/BSL- 2/BSL- 1) containment.

Accepted Answer

The answer of The deadliest, most contagious microbes are studied...

Question 20

Which of the following infectious agents is least resistant to destruction by chemical methods?

Accepted Answer

A)  bacterial endospores 
B)  fungal spores 
C)  vegetative bacterial cells 
D)  nonenveloped viruses 
E)  enveloped viruses 
A)  bacterial endospores 
B)  fungal spores 
C)  vegetative bacterial cells 
D)  nonenveloped viruses 
E)  enveloped viruses

Exam 9: Controlling Microbial Growth in the Environment

The lowest temperature that kills all cells in a broth in 10 minutes is known as the (microbial/thermal) death point.

Which of the following statements about aldehydes is FALSE?

Elements such as iodine, chlorine, and bromine are examples of (oxidizers/halogens/metals), which are the basis for many effective antimicrobial agents.

Seventy percent alcohol is effective against

By themselves, soaps have only degerming activity, not antimicrobial activity.

A(n) (iodophor/halogen) is an iodine- containing organic compound found in such antiseptics as Betadine.

Ultraviolet light penetrates (more/less) effectively than gamma rays.

The dairy creamer used in restaurants is usually treated by

The process of freeze- drying microbes to preserve them is (lyophilization/dessication).

Compare and contrast the nine major types of antimicrobial chemicals in terms of their effective on microbes.

Disinfectants known as (alcohols/oxidizers/aldehydes) have the chemical group - CHO, which reacts with and damages both proteins and nucleic acids.

The phenol coefficient is one of the most widely used measurements of an antimicrobial agent's effectiveness.

Aseptic means

Disinfectants that damage membranes include

Some viruses are inactivated by the same chemical or physical agents that damage cytoplasmic membranes.

A chemical agent that kills pathogenic microbes in general is a(n)

Which of the following statements about quaternary ammonium compounds is FALSE?

The deadliest, most contagious microbes are studied under conditions of (BSL- 4/BSL- 3/BSL- 2/BSL- 1) containment.

Which of the following infectious agents is least resistant to destruction by chemical methods?

A Brief History of Microbiology

The Chemistry of Microbiology

Cell Structure and Function

Microscopy, Staining, and Classification

Microbial Metabolism

Microbial Nutrition and Growth

Microbial Genetics

Recombinant Dna Technology

Controlling Microbial Growth in the Body: Antimicrobial Drugs

Characterizing and Classifying Prokaryotes

Characterizing and Classifying Eukaryotes

Characterizing and Classifying Viruses, Viroids, and Prions

Infection, Infectious Disease, and Epidemiology

Innate Immunity

Adaptive Immunity

Immunization and Immune Testing

Immune Disorders

Pathogenic Gram-Positive Bacteria

Pathogenic Gram-Negative Cocci and Bacilli

Rickettsias, Chlamydias, Spirochetes, and Vibrios

Pathogenic Fungi

Parasitic Protozoa, Helminths, and Arthropod Vectors

Pathogenic Dna Viruses

Pathogenic Rna Viruses

Applied and Environmental Microbiology

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