Question 1

Which of the following best describes the term 'sterilization' in the context of microbial control?

Accepted Answer

The destruction of all microorganisms and viruses in or on an object

Question 2

A hospital is preparing surgical instruments for use in an operation. Which method would be most appropriate to ensure sterility of these instruments?

Accepted Answer

Autoclaving at $121^{\circ}C$ and 15 psi for 15 minutes

Question 3

Which of the following statements about microbial death rate is correct?

Accepted Answer

Microbial death rate is often constant for a microorganism under a particular set of conditions

Question 4

Which of the following is the most resistant to antimicrobial agents?

Accepted Answer

Prions

Question 5

A laboratory is using a chemical disinfectant to clean a surface contaminated with organic material. Which factor is most likely to reduce the efficacy of the disinfectant?

Accepted Answer

Presence of organic materials

Question 6

Which of the following best explains why nonenveloped viruses are generally more resistant to harsh environmental conditions than enveloped viruses?

Accepted Answer

Nonenveloped viruses lack a lipid envelope, making them less susceptible to agents that disrupt membranes

Question 7

Which of the following is a correct statement about the use of alcohols as disinfectants?

Accepted Answer

Alcohols denature proteins and disrupt cytoplasmic membranes

Question 8

A food processing plant wants to preserve fruit juices without altering their taste or nutritional value. Which method is most appropriate?

Accepted Answer

Pasteurization

Question 9

Which of the following statements about moist heat and dry heat sterilization is correct?

Accepted Answer

Moist heat is more effective than dry heat at denaturing proteins and destroying membranes

Question 10

A researcher is using a HEPA filter in a biological safety cabinet. What is the primary function of the HEPA filter?

Accepted Answer

To remove airborne microbes and particles from the air

Question 11

Which of the following best describes the mechanism by which ionizing radiation kills microbes?

Accepted Answer

By ejecting electrons from atoms, creating ions that disrupt molecules such as DNA

Question 12

Why is hydrogen peroxide not useful for treating open wounds?

Accepted Answer

It is rapidly inactivated by catalase present in tissues

Question 13

Which of the following chemical agents is classified as a high-level germicide and is effective against endospores?

Accepted Answer

Peracetic acid

Question 14

A patient is allergic to iodine. Which alternative halogen could be used for disinfecting water?

Accepted Answer

Chlorine

Question 15

Which of the following is a disadvantage of using gaseous agents such as ethylene oxide for sterilization?

Accepted Answer

They are often highly explosive and potentially carcinogenic

Question 16

Which of the following best explains why slow freezing is more effective than quick freezing for microbial control?

Accepted Answer

Slow freezing allows for the formation of ice crystals that damage microbial cells

Question 17

A laboratory is evaluating a new disinfectant using the use-dilution test. Which result indicates the disinfectant is most effective?

Accepted Answer

No growth is observed at the highest dilution tested

Question 18

Which of the following is a real-world example of the use of heavy metals for microbial control?

Accepted Answer

Copper used to control algal growth in water reservoirs

Question 19

Which suffix indicates inhibition but not complete destruction of a type of microbe?

Accepted Answer

-static

Question 20

A hospital is concerned about the development of resistant microbes due to the overuse of disinfectants. Which of the following is a true statement regarding this concern?

Accepted Answer

Overuse of disinfectants can promote the development of resistant microbes

Controlling Microbial Growth in the Environment: Principles and Methods

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