$$\text{Water moves from inside the cell to outside} \rightarrow \text{Cell membrane shrinks away from cell wall}$$

Question 1

Which of the following best explains why salt curing is an effective method for preserving meat?

Accepted Answer

Salt creates a hypertonic environment, causing microbial cells to lose water and undergo plasmolysis.

Question 2

A copper vessel is used for storing water in some cultures. Which antimicrobial property of copper is most relevant to this practice?

Accepted Answer

Copper ions disrupt microbial cell membranes and denature proteins.

Question 3

Which of the following statements about prions is correct based on their resistance to microbial control methods?

Accepted Answer

Prions are the most resistant infectious agents to physical and chemical control methods.

Question 4

A hospital uses Lysol disinfectant spray to clean surfaces. Which type of microorganism is most likely to survive this treatment?

Accepted Answer

Endospores of bacteria

Question 5

Which equation best represents the process of plasmolysis in bacteria exposed to high salt concentrations?

Accepted Answer

$$	ext{Water moves from inside the cell to outside} ightarrow 	ext{Cell membrane shrinks away from cell wall}$$

Question 6

Which of the following is a primary reason why pickling preserves food?

Accepted Answer

Pickling lowers the pH, inhibiting the growth of most bacteria and fungi.

Question 7

During the Black Death, plague doctors wore masks with beaks. What was the primary purpose of these masks?

Accepted Answer

To filter out airborne pathogens using aromatic substances.

Question 8

Which of the following best describes the difference between antiseptics and disinfectants?

Accepted Answer

Antiseptics are used on living tissue, while disinfectants are used on inanimate surfaces.

Question 9

Which of the following microorganisms is most resistant to microbial control methods, according to the resistance hierarchy?

Accepted Answer

Prions

Question 10

A patient is infected with Mycobacterium tuberculosis. Which property of this bacterium makes it difficult to control?

Accepted Answer

It has a waxy cell wall rich in mycolic acid, making it resistant to many disinfectants.

Question 11

Which of the following best explains why copper surfaces are used in hospitals to reduce microbial contamination?

Accepted Answer

Copper surfaces release ions that disrupt microbial cell membranes and proteins.

Question 12

Which of the following is the correct sequence for the resistance of microorganisms to chemical agents, from most to least resistant?

Accepted Answer

Prions \u003e Endospores of bacteria \u003e Mycobacteria \u003e Cysts of protozoa \u003e Viruses with lipid envelopes

Question 13

Which of the following best describes the effect of hypertonic solutions on microbial cells?

Accepted Answer

Cells shrink and undergo plasmolysis due to water loss.

Question 14

Which of the following is a reason why viruses with lipid envelopes are less resistant to disinfectants than naked viruses?

Accepted Answer

Lipid envelopes are easily disrupted by detergents and alcohols.

Question 15

Which of the following best explains why dried meat is less susceptible to microbial spoilage?

Accepted Answer

Drying removes water, reducing microbial growth by limiting metabolic activity.

Question 16

Which of the following best describes the action of chlorhexidine as an antiseptic?

Accepted Answer

Chlorhexidine disrupts microbial cell membranes and denatures proteins.

Question 17

Which of the following best explains why Gram-negative bacteria are generally more resistant to disinfectants than Gram-positive bacteria?

Accepted Answer

Gram-negative bacteria have an outer membrane that restricts entry of many chemicals.

Question 18

Which of the following best describes the microbial control achieved by pickling cucumbers?

Accepted Answer

Pickling creates a hypertonic environment and lowers pH, inhibiting microbial growth.

Question 19

Which of the following best explains why medical personnel wear protective suits during outbreaks of contagious diseases?

Accepted Answer

Protective suits prevent direct contact with infectious agents and block airborne transmission.

Control of Microbial Growth: Traditional and Modern Methods

Study Guide - Practice Questions