Question 1

All the following are correct about detergents, except:

Accepted Answer

The answer of All the following are correct about detergents,...

Question 2

All of the following are benefits of food irradiation, except:

Accepted Answer

Food irradiation does not make the food less nutritious. In fact, it can help preserve some nutrients in certain foods.

Question 3

The easiest microbial forms to kill or inhibit are:

Accepted Answer

Vegetative bacteria and fungi are the easiest microbial forms to kill or inhibit. They are actively growing and reproducing, and therefore more vulnerable to antimicrobial agents. Other microbial forms such as endospores and protozoan cysts have protective structures that make them more resistant to disinfection and sterilization methods. Mycobacterium and Staphylococcus, while not as resistant as endospores, have cell wall structures that make them more difficult to kill than vegetative bacteria and fungi. Naked viruses are not easily killed by disinfectants because they do not have a protective envelope.

Question 4

The sterilizing gas used in a special chamber is:

Accepted Answer

Ethylene oxide is commonly used as a sterilizing gas in a special chamber due to its ability to penetrate various materials, including plastics, fabrics, and metals, and effectively kill microbial organisms. It is also less corrosive than other sterilizing agents like formaldehyde and glutaraldehyde, making it a more suitable option for delicate medical equipment and devices.

Question 5

Which of the following is officially accepted as a sterilant and high-level disinfectant?

Accepted Answer

Glutaraldehyde is officially accepted as both a sterilant and high-level disinfectant by regulatory agencies such as the EPA and FDA. The other options listed are not typically used for sterilization or high-level disinfection.

Question 6

All of the following are phenols or phenolics, except:

Accepted Answer

Chloramines are not phenols or phenolics, they are a class of compounds that contain both chlorine and nitrogen. The other options are all phenols or phenolics, which are compounds that contain a hydroxyl group (-OH) attached to an aromatic ring.

Question 7

All of the following pertain to hypochlorites, except:

Accepted Answer

Hypochlorites are not found in iodophors, which are compounds containing iodine that are often used as disinfectants.

Question 8

The chemical agent that produces highly reactive hydroxyl-free radicals and also decomposes to O₂ gas is:

Accepted Answer

The chemical agent that produces highly reactive hydroxyl-free radicals and also decomposes to gas is hydrogen peroxide.

Question 9

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

Accepted Answer

The compound described in the question is chlorhexidine, which fits the description of being an organic base containing chlorine and two phenolic rings. Chlorhexidine is commonly used as an antiseptic for handscrubbing, neonatal washes, wound degerming, and prepping surgical skin sites. Therefore, the best choice is B).

Question 10

Which is mismatched?

Accepted Answer

Merthiolate contains mercury, not silver.

Question 11

Which of the following is being used to replace hypochlorites in treating water because of the possibility of cancer-causing substances being produced?

Accepted Answer

The answer of Which of the following is being used...

Question 12

Alcohols:

Accepted Answer

All of the choices are correct. Alcohols are commonly used as disinfectants and antiseptics due to their ability to denature proteins, dissolve cell membrane lipids, and act as skin degerming agents. Concentrations of 50-95% are most effective for these purposes.

Question 13

Which of the following chemicals is a disinfectant for soft contact lenses?

Accepted Answer

Hydrogen peroxide is a common disinfectant for soft contact lenses, as it can effectively kill microorganisms without damaging the lenses themselves. Other options such as alcohol, hexachlorophene, glutaraldehyde, and hypochlorites can be too harsh and abrasive for use on soft contact lenses.

Question 14

All of the following are methods of disinfection or sterilization, except:

Accepted Answer

Lyophilization, or freeze-drying, is a method used for the preservation of products by removing water from them, not for disinfection or sterilization. It is primarily used to extend the shelf life of products or make them more convenient for transport. Gamma radiation, dry oven, triclosan, and ethanol are all methods or agents used for disinfection or sterilization.

Question 15

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

Accepted Answer

Ultraviolet light is not effective for killing Mycobacteria in a capped culture tube because it cannot penetrate the cap or the culture medium.

Question 16

Which of the following is not used as an antiseptic?

Accepted Answer

Aqueous glutaraldehyde is primarily used as a disinfectant and sterilant, not as an antiseptic.

Question 17

Iodophors include:

Accepted Answer

Iodophors are compounds that release iodine slowly and are used as disinfectants. Betadine is the only option listed that is an iodophor, making it the best choice. Chloramines and chlorhexidine are not iodophors, and tincture of iodine is not as effective as an iodophor due to the rapid evaporation of the iodine. Alcohols do not contain iodine and are not considered iodophors.

Question 18

All of the following are correct about iodophors, except:

Accepted Answer

Iodophors actually release iodine slowly over a longer period of time, which is why they are often used as antiseptics.

Question 19

All of the following are correct about food irradiation, except:

Accepted Answer

The World Health Organization does endorse food irradiation as a safe and effective method of food preservation, therefore option B is incorrect.

Question 20

Ethylene oxide is:

Accepted Answer

Ethylene oxide is a sporicidal agent that is effective against a wide range of microorganisms including bacteria, viruses, fungi, and spores. It is commonly used for sterilization of medical devices and equipment.

Quiz 11: Physical and Chemical Agents for Microbial Control