Q: Which of the following statements about the effectiveness of UV radiation is correct?

UV radiation is most effective at a wavelength of $$260\,\text{nm}.$$

Question 1

Which of the following best defines sterilization?

Accepted Answer

A process that destroys all viable microorganisms, including viruses and bacterial endospores.

Question 2

Which microbial form is the most resistant to physical and chemical control agents?

Accepted Answer

Prions

Question 3

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

Accepted Answer

Ethylene oxide gas sterilization

Question 4

Which of the following statements about microbicidal and microbistatic agents is correct?

Accepted Answer

Microbicidal agents kill microorganisms, while microbistatic agents inhibit their growth.

Question 5

Which of the following is NOT a cellular target for physical and chemical antimicrobial agents?

Accepted Answer

Mitochondria

Question 6

A solution is prepared by dissolving 1 gram of a disinfectant in 999 mL of water. What is the concentration in parts per million (ppm)? Use $$1\,	ext{g} = 1000\,	ext{mg}.$$

Accepted Answer

$$1000\,	ext{ppm}$$

Question 7

Which of the following best describes the action of moist heat on microorganisms?

Accepted Answer

It coagulates and denatures proteins, leading to cell death.

Question 8

A laboratory technician needs to sterilize a metal inoculating loop. Which method should be used?

Accepted Answer

Incineration in a Bunsen burner flame

Question 9

Which of the following statements about the effectiveness of UV radiation is correct?

Accepted Answer

UV radiation is most effective at a wavelength of $$260\,	ext{nm}.$$

Question 10

Which of the following is a disadvantage of using boiling water for disinfection?

Accepted Answer

Items can be easily recontaminated when removed from the water.

Question 11

Which of the following is the correct definition of thermal death time (TDT)?

Accepted Answer

The shortest length of time required to kill all test microbes at a specified temperature.

Question 12

Which of the following is a limitation of using osmotic pressure (e.g., salting or sugaring) as a method of microbial control?

Accepted Answer

It is never a sterilizing technique.

Question 13

Which of the following is a desirable characteristic of a chemical germicide used in healthcare settings?

Accepted Answer

It should have broad-spectrum microbicidal action without being toxic to human tissues.

Question 14

Which of the following statements about filtration as a microbial control method is correct?

Accepted Answer

Filtration can be used to sterilize heat-sensitive liquids such as vaccines.

Question 15

Which of the following is an example of antisepsis?

Accepted Answer

Swabbing an open wound with hydrogen peroxide

Question 16

Which of the following factors does NOT affect the germicidal activity of a chemical agent?

Accepted Answer

Color of the chemical agent

Question 17

Which of the following is true regarding the use of alcohol-based hand sanitizers during the COVID-19 pandemic?

Accepted Answer

They are effective because the viral envelope is susceptible to alcohol.

Question 18

Which of the following is the best definition of microbial death?

Accepted Answer

Permanent loss of reproductive capability, even under optimum growth conditions

Question 19

Which of the following is a high-level germicide?

Accepted Answer

A chemical that kills endospores and can be used as a sterilant

Question 20

Which of the following is a correct statement about the effect of organic matter on disinfectants?

Accepted Answer

Organic matter can inhibit the action of disinfectants and heat.

Physical and Chemical Control of Microbes: Chapter 9 Study Notes

Study Guide - Practice Questions

Study Guide - Flashcards