Question 1

Which of the following best describes the difference between sterilization and disinfection?

Accepted Answer

Sterilization removes all microbial life, while disinfection only removes pathogens.

Question 2

A hospital is deciding between using phenolics and alcohols for disinfecting surfaces contaminated with Mycobacteria. Based on the provided data, which agent is more effective and why?

Accepted Answer

Alcohols, because they have good activity against Mycobacteria, while phenolics only have poor activity.

Question 3

Which of the following statements about the effectiveness of antimicrobial treatments is correct?

Accepted Answer

The higher the initial number of microbes, the longer it takes to achieve sterilization.

Question 4

Which physical method of microbial control is most appropriate for sterilizing heat-sensitive solutions?

Accepted Answer

Filtration

Question 5

A laboratory technician needs to sterilize glassware. Which of the following methods would be most effective?

Accepted Answer

Hot-air sterilization at $$170^\circ C$$ for 2 hours

Question 6

Which of the following agents is most effective against both endospores and Mycobacteria?

Accepted Answer

Glutaraldehyde

Question 7

Which of the following best explains why prions are the most resistant to chemical and physical methods of microbial control?

Accepted Answer

Prions lack nucleic acids and are composed of abnormally folded proteins, making them resistant to denaturation.

Question 8

Which of the following soaps would be classified as a degerming agent rather than an antiseptic?

Accepted Answer

Ivory bar soap

Question 9

A researcher is using an autoclave to sterilize media. What are the standard conditions for autoclaving to achieve sterilization?

Accepted Answer

$$121^\circ C$$ for 15 minutes under pressure

Question 10

Which of the following statements about the disk-diffusion method is correct?

Accepted Answer

It measures the zone of inhibition to evaluate the effectiveness of chemical disinfectants.

Question 11

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

Accepted Answer

Prions \u003e Endospores of bacteria \u003e Mycobacteria \u003e Gram-negative bacteria \u003e Viruses with lipid envelopes

Question 12

Which of the following statements about the use of UV light for microbial control is correct?

Accepted Answer

UV light causes damage to microbial DNA, leading to cell death.

Question 13

A food processing plant wants to reduce spoilage organisms and pathogens in milk without significantly altering its taste. Which method should they use?

Accepted Answer

Pasteurization

Question 14

Which of the following best describes the mechanism of action of quaternary ammonium compounds (quats)?

Accepted Answer

Alteration of membrane permeability

Question 15

A patient with a wound is treated with Betadine. What is the primary mechanism by which Betadine acts as an antiseptic?

Accepted Answer

Membrane disruption and impairment of protein synthesis

Question 16

Which of the following statements about the effectiveness of soap and water compared to 70% ethanol is supported by the provided data?

Accepted Answer

70% ethanol is more effective at reducing bacterial survival over time than soap and water.

Question 17

Which of the following best explains why low temperature inhibits microbial growth?

Accepted Answer

It slows down metabolic reactions and enzyme activity.

Question 18

A microbiologist is comparing the effectiveness of different disinfectants using the disk-diffusion method. What does a larger zone of inhibition indicate?

Accepted Answer

Greater effectiveness of the disinfectant against the tested microbe.

Question 19

Which of the following is a real-world example of degerming?

Accepted Answer

Washing hands with soap and water before surgery

Question 20

Which of the following statements about the use of high pressure in microbial control is correct?

Accepted Answer

High pressure denatures proteins, leading to microbial death.

Microbial Growth II

Study Guide - Practice Questions

Study Guide - Flashcards