Question 1

Which of the following best describes the role of Toll-like receptors (TLRs) in innate immunity?

Accepted Answer

TLRs recognize pathogen-associated molecular patterns (PAMPs) and induce cytokine release.

Question 2

A patient presents with a high white blood cell (WBC) count. Which of the following is the most likely cause?

Accepted Answer

Autoimmune disease

Question 3

Which of the following is NOT a physical factor involved in the first line of defense against pathogens?

Accepted Answer

Lysozyme in tears

Question 4

Which of the following statements about normal microbiota is TRUE?

Accepted Answer

They compete with pathogens for nutrients and space, providing protection.

Question 5

Which cell type is most active in the early stages of a bacterial infection and is considered a 'first responder'?

Accepted Answer

Neutrophil

Question 6

During phagocytosis, what is the role of opsonization?

Accepted Answer

It coats the microorganism with serum proteins to enhance adherence by phagocytes.

Question 7

Which of the following is a function of inflammation?

Accepted Answer

To destroy injurious agents and repair damaged tissue

Question 8

A patient with a genetic deficiency in complement proteins would MOST likely experience which of the following?

Accepted Answer

Increased susceptibility to bacterial infections

Question 9

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

Accepted Answer

Fever enhances the activity of phagocytes and T cells.

Question 10

Which of the following is a correct sequence of events in the process of inflammation?

Accepted Answer

Vasodilation → Phagocyte migration → Tissue repair

Question 11

Which of the following antimicrobial substances is correctly matched with its function?

Accepted Answer

Transferrin – binds iron to limit bacterial growth

Question 12

A bacterial pathogen produces a capsule that prevents C3b binding. What is the most likely consequence?

Accepted Answer

The pathogen will evade the complement system and resist immune clearance.

Question 13

Which of the following is a characteristic of the alternative pathway of complement activation?

Accepted Answer

It is triggered by factors B, D, and P binding to microbial surfaces.

Question 14

Which of the following best describes the function of interferons?

Accepted Answer

They induce neighboring cells to produce antiviral proteins.

Question 15

A patient with a severe bacterial infection develops a dangerously high fever. Which of the following complications is most likely if the fever is not controlled?

Accepted Answer

Seizures and coma

Question 16

Which of the following is an example of a chemical factor in the first line of defense?

Accepted Answer

Low pH of gastric juice

Question 17

Which of the following best explains why infants and the elderly are more susceptible to infectious diseases?

Accepted Answer

Their immune systems are less developed or weakened.

Question 18

Which of the following is a correct description of diapedesis?

Accepted Answer

The movement of phagocytes between endothelial cells to reach infected tissue

Question 19

Which of the following is a function of antimicrobial peptides?

Accepted Answer

They inhibit cell wall synthesis and form pores in microbial membranes.

Question 20

A patient with sickle cell trait is less susceptible to malaria. This is an example of which type of defense?

Accepted Answer

Genetic resistance

Innate Immunity: Nonspecific Defenses of the Host – Study Guide

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