Question 1

Which of the following describes flash pasteurization?
A) heating at 63°C for 30 minutes
B) heating at 72°C for 15 seconds
C) heating at 72°C for 15 minutes
D) heating at 134°C for one second
E) passing liquid through steam at 140°C

Accepted Answer

Flash pasteurization involves heating liquid, typically food or beverage products, at a high temperature for a short period of time in order to kill any harmful bacteria or pathogens. Option B describes the temperature and time frame commonly used for flash pasteurization.

Question 2

Methods of microbial control called ________ arrest the growth of microbes.
A) microbicial
B) microbistatic
C) sanitizing
D) degerming
E) antiseptic

Accepted Answer

Microbistatic methods only inhibit the growth and reproduction of microbes, rather than killing them outright.

Question 3

Silvadene,a topical treatment for burns,contains 1% silver.What category of chemical control agent is in Silvadene?
A) halogens
B) heavy metals
C) oxidizing agents
D) aldehydes
E) surfactants

Accepted Answer

Silvadene contains 1% silver, which is a heavy metal. Heavy metals can act as chemical control agents by disrupting the normal functioning of microbial cells.

Question 4

Which of the following is the most difficult to inactivate?
A) enveloped viruses
B) fungus spores
C) bacterial endospores
D) nonenveloped viruses
E) protozoan cysts

Accepted Answer

Bacterial endospores are the most difficult to inactivate due to their complex and resistant structure. They have a tough outer coat that protects the spore from chemical and physical agents, making them highly resistant to disinfection and sterilization methods. Enveloped viruses, nonenveloped viruses, fungus spores, and protozoan cysts are all susceptible to various disinfectants and sterilization methods.

Question 5

A chemical used to reduce potential pathogens on the skin is a(n)
A) antiseptic.
B) disinfectant.
C) sanitizer.
D) sterilizing agent.
E) degermer.

Accepted Answer

Antiseptics are chemicals used to reduce potential pathogens on the skin. They are specifically intended for use on living tissue and are gentler than harsher disinfectants. Disinfectants, on the other hand, are used on inanimate objects and surfaces to kill potential pathogens. Sanitizers are also used on inanimate objects and surfaces but are less effective than disinfectants. Sterilizing agents are used to completely eliminate all microorganisms, including pathogens. Degermers are used to physically remove microorganisms from the skin, rather than killing them.

Question 6

Standard pasteurization methods are used to
A) reduce microbes that cause spoilage.
B) remove all thermoduric microbes.
C) reduce microbes that cause disease.
D) remove all microbes.
E) reduce microbes that cause disease or spoilage.

Accepted Answer

Standard pasteurization methods are designed to reduce or destroy microbes that can cause both disease and spoilage, making option E the best choice. The goal is not to completely remove all microbes, as that would be impractical and unnecessary for most applications. The process usually achieves a 99.9% reduction in the number of microbes present in the product, which is sufficient to make it safe for consumption while preserving its quality.

Question 7

An instrument that will come into contact with only the skin of a patient should be disinfected with a(n)
A) high-level germicide.
B) low-level germicide.
C) intermediate-level germicide.
D) degerming agent only.
E) germistatic agent only.

Accepted Answer

Instruments that come into contact with only the skin of a patient are considered non-critical and require low-level disinfection. Low-level germicides are sufficient to kill most bacteria, some viruses, and some fungi, but do not necessarily kill spores or all viruses. This level of disinfection is appropriate for items that do not penetrate sterile tissues or mucous membranes.

Question 8

Which of the following types of radiation is nonionizing and has the shortest wavelength?
A) ultraviolet light
B) infrared radiation
C) microwaves
D) X rays
E) gamma rays

Accepted Answer

Ultraviolet light is nonionizing and has the shortest wavelength among the options provided. While X-rays and gamma rays have shorter wavelengths, they are ionizing, not nonionizing.

Question 9

Which of the following is NOT a feature associated with filtration?
A) nitrocellulose or plastic membrane filters
B) sterilization of heat-sensitive materials
C) varying thicknesses of membrane filters used
D) use of HEPA filters to filter air
E) ability of some filters to trap viruses and proteins

Accepted Answer

Filtration involves the use of nitrocellulose or plastic membrane filters, is often used for sterilizing heat-sensitive materials, can involve the use of HEPA filters to clean air, and some filters are indeed capable of trapping very small particles like viruses and proteins. The thickness of membrane filters, however, is not typically varied as a feature of filtration; rather, it's the pore size of the filters that is adjusted to trap particles of different sizes.

Question 10

Which of the following is used for microbial control in fresh fruits and vegetables?
A) X rays
B) ultraviolet light
C) electron beams
D) microwaves
E) gamma rays

Accepted Answer

Gamma rays are used for microbial control in fresh fruits and vegetables. Gamma rays are highly penetrating and can kill bacteria, viruses, and fungi without damaging the quality of the food. They are useful for reducing the risk of foodborne illness and increasing the shelf life of produce. X rays, ultraviolet light, electron beams, and microwaves are not typically used for microbial control in fresh fruits and vegetables.

Question 11

Which of the following is an example of pasteurization?
A) A public toilet is treated with disinfectants.
B) A surgeon washes her hands before surgery.
C) Heat is used to kill potential pathogens in apple juice.
D) An autoclave is used to prepare nutrient agar.
E) A nurse prepares an injection site with an alcohol swab.

Accepted Answer

Pasteurization involves using heat to kill potential pathogens in food or drink, like in the case of apple juice. The other options listed are examples of different types of disinfection or sterilization techniques.

Question 12

Which of the following is bacteriostatic?
A) heating in an oven at 171°C for an hour
B) freezing below 0°C
C) filtration
D) autoclaving
E) flash pasteurization

Accepted Answer

Freezing below 0°C is bacteriostatic because it inhibits the growth of bacteria without killing them, allowing their revival when conditions become favorable again.

Question 13

Which of the following can be used to disinfect air?
A) HEPA filters
B) ethylene oxide
C) ultraviolet light
D) both HEPA filters and ultraviolet light
E) both ethylene oxide and ultraviolet light

Accepted Answer

Both HEPA filters and ultraviolet light can be used to disinfect air. HEPA filters trap and remove airborne particles, including viruses and bacteria, while ultraviolet light kills the microorganisms. As a result, using both methods together can significantly reduce the number of harmful pathogens in the air. Ethylene oxide, on the other hand, is a chemical sterilant that is typically used to disinfect medical equipment and supplies, but is not recommended for air disinfection.

Question 14

A chemical agent that dissolves lipids can damage
A) cells.
B) bacterial endospores.
C) enveloped viruses.
D) nonenveloped and enveloped viruses.
E) cells and enveloped viruses.

Accepted Answer

Lipids are a major component of cell membranes and enveloped viruses. Therefore, a chemical agent that dissolves lipids can damage both cells and enveloped viruses. Nonenveloped viruses, on the other hand, do not possess a lipid envelope and are less susceptible to damage from lipid-dissolving agents. Bacterial endospores, being highly resistant structures, are also less susceptible to damage from such agents.

Question 15

Antimicrobial agents that damage nucleic acids also affect
A) the cell wall.
B) the cell membrane.
C) the viral envelope.
D) endospores.
E) protein synthesis.

Accepted Answer

The answer of Antimicrobial agents that damage nucleic acids also...

Question 16

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

Accepted Answer

The answer of Aseptic means
A) sterile.
B) free of all microbes.
C)...

Question 17

Which of the following statements is TRUE of disinfectants?
A) They are effective in destroying endospores.
B) They are used on living tissue.
C) They are used for sterilization.
D) They are used on inanimate surfaces.
E) They are only effective for short periods of time (seconds to minutes).

Accepted Answer

Disinfectants are used on inanimate surfaces to kill or remove microorganisms. They are not effective in destroying endospores and are not used for sterilization. Antiseptics are used on living tissue, and the effectiveness of disinfectants can vary, with some being effective for longer periods of time than others.

Question 18

You notice a sign in a public restroom that states "Sanitized for your safety." This means
A) sterilizing chemicals have been used in cleaning.
B) antiseptics have been used to clean the area.
C) degerming methods only have been used to clean the restroom.
D) methods of disinfection that meet minimum standards of microbial removal have been used.
E) only "organic" chemicals were used in the cleaning process to reduce microbial numbers.

Accepted Answer

The sign's statement indicates that methods of disinfection that meet minimum standards of microbial removal have been used to clean the restroom, ensuring that it is safe to use.

Question 19

Which of the following is the most appropriate pairing of microbe and biosafety level?
A) E. coli, BSL-3
B) anthrax, BSL-1
C) Ebola, BSL-2
D) methicillin-resistant Staphylococcus aureus (MRSA), BSL-2
E) tuberculosis, BSL-1

Accepted Answer

MRSA is classified as a BSL-2 organism because it can cause disease in healthy individuals and is resistant to many antibiotics, but can be safely handled with standard microbiological practices and proper personal protective equipment. E. coli is also a BSL-2 organism. Anthrax, Ebola, and tuberculosis are all BSL-3 organisms, as they can pose a significant risk of infection and require higher levels of containment and specialized equipment for handling.

Question 20

Boiling water for 10 minutes is effective in ridding it of
A) actively growing bacteria.
B) enveloped viruses.
C) bacterial endospores.
D) protozoan cysts.
E) both growing bacteria and enveloped viruses.

Accepted Answer

Boiling water for 10 minutes is effective in killing actively growing bacteria and enveloped viruses. The high temperature denatures proteins and disrupts membranes, effectively inactivating these microorganisms. However, it may not be sufficient to destroy bacterial endospores or protozoan cysts, which can survive extreme conditions.

Quiz 9: Controlling Microbial Growth in the Environment

Which of the following describes flash pasteurization?

Methods of microbial control called ________ arrest the growth of microbes.

Silvadene,a topical treatment for burns,contains 1% silver.What category of chemical control agent is in Silvadene?

Which of the following is the most difficult to inactivate?

A chemical used to reduce potential pathogens on the skin is a(n)

Standard pasteurization methods are used to

An instrument that will come into contact with only the skin of a patient should be disinfected with a(n)

Which of the following types of radiation is nonionizing and has the shortest wavelength?

Which of the following is NOT a feature associated with filtration?

Which of the following is used for microbial control in fresh fruits and vegetables?

Which of the following is an example of pasteurization?

Which of the following is bacteriostatic?

Which of the following can be used to disinfect air?

A chemical agent that dissolves lipids can damage

Antimicrobial agents that damage nucleic acids also affect

Aseptic means

Which of the following statements is TRUE of disinfectants?

You notice a sign in a public restroom that states "Sanitized for your safety." This means

Which of the following is the most appropriate pairing of microbe and biosafety level?

Boiling water for 10 minutes is effective in ridding it of