Question 1

Which of the following best describes the difference between droplet transmission and airborne transmission of infectious diseases?

Accepted Answer

Droplet transmission involves pathogens in respiratory droplets expelled during coughing or sneezing, which travel short distances, while airborne transmission involves pathogens in smaller particles that can remain suspended and travel longer distances.

Question 2

A hospital patient develops a urinary tract infection after catheterization. This infection is best classified as:

Accepted Answer

A nosocomial infection

Question 3

Which of the following statements about mechanical and biological transmission by arthropod vectors is correct?

Accepted Answer

Mechanical transmission involves the vector passively carrying pathogens on its body, while biological transmission involves the pathogen multiplying inside the vector before transmission.

Question 4

Given the following data for two pathogens: Pathogen A has $$ID_{50} = 10$$ cells and $$LD_{50} = 100$$ cells; Pathogen B has $$ID_{50} = 100$$ cells and $$LD_{50} = 1000$$ cells. Which pathogen is more virulent?

Accepted Answer

Pathogen A, because it requires fewer cells to infect and kill 50% of the population.

Question 5

Which of the following is NOT a virulence factor that helps bacteria evade host defenses?

Accepted Answer

Ribosomes

Question 6

A bacterial pathogen produces coagulase, which causes blood clotting. How does this enzyme contribute to pathogenicity?

Accepted Answer

It helps the pathogen evade phagocytosis by forming a protective clot around itself.

Question 7

Which of the following best describes the role of interferons in innate immunity?

Accepted Answer

Interferons cause uninfected cells to produce antiviral proteins, limiting viral replication.

Question 8

During inflammation, which of the following is a primary effect of histamine release?

Accepted Answer

Increased permeability of capillaries, allowing immune cells to enter tissues

Question 9

Which of the following is a correct sequence of steps in phagocytosis?

Accepted Answer

Chemotaxis → Adherence → Ingestion → Digestion → Discharge of waste

Question 10

Which of the following best explains why fever can be beneficial during infection?

Accepted Answer

Fever raises body temperature, which can inhibit the growth of some pathogens and enhance immune responses.

Question 11

Which of the following statements about humoral and cellular immunity is correct?

Accepted Answer

Humoral immunity involves antibodies produced by B cells, while cellular immunity involves T cells targeting infected or abnormal cells.

Question 12

Which of the following is an example of artificially acquired passive immunity?

Accepted Answer

Receiving monoclonal antibodies for treatment of a disease

Question 13

A vaccine containing a weakened (attenuated) microorganism is most likely to:

Accepted Answer

Elicit a strong immune response but carry a risk of causing disease in immunocompromised individuals.

Question 14

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

Accepted Answer

The drug targets microbial structures or functions not found in host cells, minimizing harm to the host.

Question 15

Which of the following antimicrobial drugs acts by inhibiting cell wall synthesis?

Accepted Answer

Penicillin

Question 16

Why are antibiotics ineffective against viral infections such as influenza or COVID-19?

Accepted Answer

Viruses lack cell walls and metabolic pathways targeted by antibiotics.

Question 17

A disk diffusion test is performed to evaluate the effectiveness of several antibiotics against a bacterial strain. Which result indicates the most effective antibiotic?

Accepted Answer

The antibiotic with the largest zone of inhibition around the disk.

Question 18

Which of the following best describes how bacteria can become resistant to antibiotics?

Accepted Answer

By acquiring mutations or genes that alter drug targets, degrade drugs, or pump drugs out of the cell.

Question 19

Which of the following is a real-world example of antimicrobial drug synergy?

Accepted Answer

Using penicillin and streptomycin together to achieve a greater effect than either drug alone.

Comprehensive Study Notes: Principles of Disease, Pathogenicity, Immunity, Vaccines, and Antimicrobial Drugs

Study Guide - Practice Questions

Study Guide - Flashcards