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

Gaseous ethylene oxide treatment.

Question 3

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

Accepted Answer

A constant percentage of the extant population is killed each minute.

Question 4

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

Accepted Answer

Prions

Question 5

Which physical method is considered the 'ultimate means of sterilization' and is used to destroy prions?

Accepted Answer

Incineration

Question 6

Why is moist heat 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 best describes the action of alcohols as antimicrobial agents?

Accepted Answer

They denature proteins and disrupt cell membranes by removing water from cells.

Question 8

A solution is treated with a chemical that kills fungal spores, protozoan cysts, viruses, and pathogenic bacteria, but not bacterial endospores. What level of germicide is this?

Accepted Answer

Intermediate-level germicide

Question 9

Which of the following is a disadvantage of using hydrogen peroxide as a disinfectant for open wounds?

Accepted Answer

It is neutralized by catalase present in tissues.

Question 10

Which of the following chemical agents is used to prevent blindness caused by Neisseria gonorrhoeae in newborns?

Accepted Answer

1% silver nitrate

Question 11

A laboratory technician needs to sterilize a solution containing heat-sensitive enzymes. Which method should be used?

Accepted Answer

Filtration through a $$0.22\ \mu m$$ filter

Question 12

Which of the following best explains why refrigeration is considered a '-static' process?

Accepted Answer

It inhibits microbial growth without killing cells.

Question 13

Which of the following is a real-world application of lyophilization?

Accepted Answer

Long-term preservation of microbial cultures.

Question 14

Which of the following is the primary mode of action for aldehydes as antimicrobial agents?

Accepted Answer

Cross-linking functional groups to denature proteins and inactivate nucleic acids.

Question 15

Which of the following is a major advantage of phenolic compounds as disinfectants?

Accepted Answer

They remain active in the presence of organic matter.

Question 16

Which of the following best describes the effect of nonionizing radiation (such as UV light) on microbial cells?

Accepted Answer

It causes thymine dimers in DNA, inhibiting replication and transcription.

Question 17

Which of the following is the best target for selective toxicity in antimicrobial agents?

Accepted Answer

Cell wall synthesis

Question 18

A patient is about to receive an injection. Which of the following is the most appropriate method for cleaning the skin at the injection site?

Accepted Answer

Swabbing with 70% ethanol

Question 19

Which of the following statements about quaternary ammonium compounds (quats) is correct?

Accepted Answer

They are positively charged detergents that disrupt cellular membranes.

Question 20

Which of the following is a limitation of dry heat sterilization?

Accepted Answer

It is time-consuming due to slow heat penetration.

Controlling Microbial Growth: Physical and Chemical Methods

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