Question 1

Which of the following best describes the process of sterilization?

Accepted Answer

The destruction of all microorganisms and viruses on an object.

Question 2

A hospital needs to sterilize heat-sensitive plastic syringes. Which method is most appropriate?

Accepted Answer

Ethylene oxide gas sterilization.

Question 3

Which of the following is the correct order of microbial resistance to chemical biocides, from most resistant to most susceptible?

Accepted Answer

Prions, bacterial endospores, mycobacteria, Gram-negative bacteria, enveloped viruses

Question 4

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

Accepted Answer

Microbial agents kill a constant percentage of cells over time.

Question 5

A nurse is preparing a patient’s skin for an injection. Which method is most appropriate for this scenario?

Accepted Answer

Degerming with an alcohol swab.

Question 6

Which of the following best explains why moist heat is generally more effective than dry heat for sterilization?

Accepted Answer

Moist heat penetrates cells more rapidly due to water’s higher heat capacity.

Question 7

Which of the following is NOT a limitation of dry heat sterilization?

Accepted Answer

It is noncorrosive for metal instruments.

Question 8

Why is boiling not considered a reliable method for sterilization?

Accepted Answer

Boiling does not kill bacterial endospores and some viruses.

Question 9

Which of the following statements about refrigeration and freezing is correct?

Accepted Answer

Refrigeration is a -static process, while freezing can be -cidal due to ice crystal formation.

Question 10

A laboratory wants to preserve a bacterial culture for several years. Which method is most appropriate?

Accepted Answer

Lyophilization

Question 11

Which pore size filter would be most appropriate for removing most bacteria from a heat-sensitive solution?

Accepted Answer

$$0.22\ \mu m$$

Question 12

Which of the following best describes the action of ionizing radiation on microbial cells?

Accepted Answer

It creates ions that disrupt hydrogen bonding, oxidize covalent bonds, and damage DNA.

Question 13

Which chemical agent is most effective for disinfecting surfaces contaminated with organic matter?

Accepted Answer

Phenolics

Question 14

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

Accepted Answer

They are highly explosive and potentially carcinogenic.

Question 15

Which of the following best explains why hydrogen peroxide is less effective for treating open wounds?

Accepted Answer

Catalase in tissues breaks down hydrogen peroxide into water and oxygen.

Question 16

Which of the following antimicrobial agents acts by cross-linking functional groups in proteins and nucleic acids?

Accepted Answer

Aldehydes

Question 17

Which of the following is the best example of selective toxicity in antimicrobial therapy?

Accepted Answer

A drug that targets peptidoglycan synthesis in bacteria.

Question 18

Which of the following is a real-world application of using heavy metals for microbial control?

Accepted Answer

Using 1% silver nitrate to prevent blindness in newborns caused by Neisseria gonorrhoeae.

Question 19

Which of the following best describes the action of surfactants such as quaternary ammonium compounds (quats)?

Accepted Answer

They disrupt cellular membranes and reduce surface tension.

Question 20

A patient is prescribed an antibiotic that inhibits protein synthesis. Which of the following is a likely target of this drug?

Accepted Answer

Ribosomal function

Controlling Microbial Growth: Physical and Chemical Methods

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