Question 1

Which of the following best describes the relationship between the human microbiome and host health?

Accepted Answer

The microbiome provides benefits such as aiding digestion and protecting against pathogens.

Question 2

A patient develops a severe infection after taking broad-spectrum antibiotics. Which concept best explains why this occurred?

Accepted Answer

Microbial antagonism was disrupted, allowing opportunistic pathogens to proliferate.

Question 3

Which of the following is an example of mutualism?

Accepted Answer

A bacterium living in the gut produces vitamin K for the host, while receiving nutrients and a stable environment.

Question 4

Which enzyme allows bacteria to break down connective tissue and spread through the host?

Accepted Answer

Collagenase

Question 5

A bacterial pathogen avoids the host immune system by changing its surface proteins. What is this process called?

Accepted Answer

Antigenic variation

Question 6

Which of the following statements about endotoxins is correct?

Accepted Answer

Endotoxins are part of the bacterial cell wall and can cause shock at high doses.

Question 7

A patient receives a vaccine that contains an inactivated toxin. What type of vaccine is this?

Accepted Answer

Toxoid vaccine

Question 8

Which immunoglobulin is most abundant in serum and indicates a past infection?

Accepted Answer

IgG

Question 9

A hospital is deciding how to sterilize surgical instruments. Which method would be most appropriate to ensure all microbial life is destroyed?

Accepted Answer

Autoclaving at $$121^\circ C$$ and 15 psi for 15 minutes

Question 10

Which of the following best describes selective toxicity in antimicrobial therapy?

Accepted Answer

The drug targets microbial structures not found in the host.

Question 11

A patient is prescribed two antibiotics that work better together than alone. This is an example of:

Accepted Answer

Synergistic effect

Question 12

Which of the following mechanisms is NOT a common way bacteria acquire antibiotic resistance?

Accepted Answer

Increased uptake of antibiotics

Question 13

A laboratory uses the Kirby-Bauer disc diffusion method to test antibiotic susceptibility. What does a large zone of inhibition indicate?

Accepted Answer

The bacteria are susceptible to the antibiotic.

Question 14

Which of the following is a characteristic of an epidemic?

Accepted Answer

A sudden increase in the number of cases above what is normally expected.

Question 15

A newborn receives antibodies from its mother through breast milk. This is an example of:

Accepted Answer

Passive natural immunity

Question 16

Which of the following best explains why viruses are more difficult to target with drugs than bacteria?

Accepted Answer

Viruses use host cell machinery for replication, limiting drug targets.

Question 17

A patient is diagnosed with a non-communicable disease. Which of the following is most likely true?

Accepted Answer

The disease cannot be spread between individuals.

Question 18

Which of the following best describes the function of an adjuvant in a vaccine?

Accepted Answer

It enhances the immune response to the antigen.

Question 19

A patient is infected with a bacterium that produces an A-B exotoxin. Which statement best describes how this toxin works?

Accepted Answer

The B subunit binds to the host cell, allowing the A subunit to enter and disrupt cell function.

Question 20

A public health official is investigating a foodborne outbreak. Which type of transmission is most likely involved?

Accepted Answer

Vehicle-borne transmission

Microbe-Host Interactions, Immunity, Microbial Control, and Epidemiology

Study Guide - Practice Questions