Question 1

Which of the following best describes the process of sterilization?

Accepted Answer

Destruction or removal of all microbial life, including endospores (but not prions)

Question 2

A hospital is deciding how to sterilize heat-sensitive surgical instruments. Which method would be most appropriate?

Accepted Answer

Filtration using a membrane filter with small pore size

Question 3

Which of the following is a major action of antimicrobial agents that leads to microbial death?

Accepted Answer

Inducing mutations in nucleic acids

Question 4

Why does hot-air sterilization require a longer time than autoclaving to achieve sterilization?

Accepted Answer

Water transfers heat faster to a cool body than air

Question 5

Which physical method is most effective for sterilizing heat-sensitive solutions such as certain antibiotics?

Accepted Answer

Filtration

Question 6

Pasteurization is used for milk and fruit juices to:

Accepted Answer

Reduce microbial contamination and slow spoilage

Question 7

Which of the following statements about HEPA filters is correct?

Accepted Answer

They trap microbes, but the microbes remain alive

Question 8

A food company uses high concentrations of salt to preserve fish. What is the primary mechanism by which this method controls microbial growth?

Accepted Answer

Causing cell shriveling through osmotic pressure

Question 9

Which type of radiation is most likely to cause thymine dimers in DNA?

Accepted Answer

Non-ionizing radiation (UV light)

Question 10

When selecting a method for microbial control, which factor is LEAST important to consider?

Accepted Answer

Color of the microbial colony

Question 11

Which of the following best describes a bacteriostatic agent?

Accepted Answer

Inhibits bacterial growth without killing

Question 12

A laboratory technician uses direct flaming to sterilize an inoculating loop. This is an example of:

Accepted Answer

Dry heat sterilization

Question 13

Which of the following is NOT a major target of antimicrobial agents?

Accepted Answer

Capsule polysaccharides

Question 14

Which method would be LEAST effective against bacterial endospores?

Accepted Answer

Boiling at $100^\circ C$ for 10 minutes

Question 15

A hospital uses UV lamps to reduce microbial contamination in operating rooms. What is the primary effect of this treatment?

Accepted Answer

Formation of thymine dimers in microbial DNA

Question 16

Which of the following statements about pasteurization is TRUE?

Accepted Answer

It reduces microbial contamination and slows spoilage

Question 17

Which of the following is an example of antisepsis?

Accepted Answer

Applying alcohol to a wound on the skin

Question 18

Which physical method of microbial control is most likely to be used for preserving jams and honey?

Accepted Answer

Osmotic pressure

Question 19

Which of the following is a correct equation for the equivalent treatments of hot-air and autoclave sterilization?

Accepted Answer

$170^\circ C$ for 2 hours = $121^\circ C$ for 15 minutes

Question 20

Which of the following is NOT a factor to consider when selecting a microbial control method?

Accepted Answer

Shape of the microbial cell

Controlling Microbial Growth in the Environment: Physical Methods and Key Concepts

Study Guide - Practice Questions