Question 1

Which of the following best describes the difference between pathogenicity and virulence?

Accepted Answer

Pathogenicity is the ability to cause disease, while virulence is the degree of damage caused by the pathogen.

Question 2

Which of the following is NOT a step that a pathogen must accomplish to establish an infection in a host?

Accepted Answer

Immediately kill the host cell upon entry

Question 3

The Black Death, which killed one-third of the European population in the 14th century, was caused by which pathogen and transmitted by what vector?

Accepted Answer

Yersinia pestis, transmitted by fleas

Question 4

Which of the following best describes normal flora?

Accepted Answer

Microbes that are permanent inhabitants of different body sites in a healthy person

Question 5

Which of the following is an example of an opportunistic pathogen?

Accepted Answer

Pseudomonas aeruginosa causing infection in an immunocompromised patient

Question 6

Which of the following statements about biofilms is TRUE?

Accepted Answer

Biofilms are communities of microorganisms embedded in a matrix of extracellular polymeric substances (EPS).

Question 7

Which of the following is a function of the eukaryotic cytoskeleton that can be exploited by pathogens?

Accepted Answer

Facilitating intracellular movement of pathogens

Question 8

Which of the following best describes quorum sensing in bacteria?

Accepted Answer

A form of cell-to-cell communication that coordinates group behaviors based on population density

Question 9

Which of the following is a genetically encoded virulence factor?

Accepted Answer

Shiga toxin in EHEC

Question 10

Which of the following is a key difference between prokaryotic and eukaryotic cells?

Accepted Answer

Eukaryotic cells have membrane-bound organelles, while prokaryotic cells do not.

Question 11

Which of the following is the correct sequence in the chain of infection?

Accepted Answer

Causative agent → Reservoir → Portal of exit → Mode of transmission → Portal of entry → Person at risk

Question 12

Which of the following best explains why biofilms are a concern in infectious diseases?

Accepted Answer

Biofilms protect pathogens from antibiotics and immune responses, making infections harder to treat.

Question 13

Which of the following is TRUE about the plasma membrane of eukaryotic cells?

Accepted Answer

It acts as the first barrier that pathogens must cross to infect the cell.

Question 14

Which of the following is an example of a primary pathogen?

Accepted Answer

Influenza virus causing flu in a healthy individual

Question 15

Which of the following is a function of cilia in the respiratory tract?

Accepted Answer

Moving mucus and trapped pathogens out of the lungs

Question 16

Which of the following best describes a pathogenicity island?

Accepted Answer

A cluster of virulence genes found in the chromosome or plasmids of a pathogen

Question 17

Which of the following is a real-life example of quorum sensing?

Accepted Answer

Vibrio fischeri producing light in the Hawaiian bobtail squid

Question 18

Which of the following is NOT a characteristic of normal flora?

Accepted Answer

Always causes disease in the host

Question 19

Which of the following is TRUE regarding ribosomes in the context of infection?

Accepted Answer

Viruses hijack host ribosomes to synthesize viral proteins.

Question 20

Which of the following best describes the role of flagella in bacteria?

Accepted Answer

They provide motility, allowing bacteria to move toward favorable environments.

An Introduction to Cell Structure and Host-Pathogen Relationships

Study Guide - Practice Questions