Question 1

Which of the following best describes the main difference between innate and adaptive immunity?

Accepted Answer

Innate immunity provides immediate, non-specific defense, while adaptive immunity develops over time and is specific to particular pathogens.

Question 2

A patient with a deficiency in mannose-binding lectin (MBL) would have the most direct impairment in which immune process?

Accepted Answer

Activation of the lectin complement pathway

Question 3

Which of the following is NOT a function of normal microbiota in shaping immune responses?

Accepted Answer

Directly producing antibodies against pathogens

Question 4

Which of the following is an example of a mechanical barrier in the first line of defense?

Accepted Answer

Mucociliary escalator in the respiratory tract

Question 5

A child presents with recurrent bacterial infections and is found to have neutropenia. Which of the following best explains the clinical findings?

Accepted Answer

Low neutrophil count reduces the body's ability to phagocytize and destroy bacteria.

Question 6

Which of the following best describes the role of cytokines in the immune response?

Accepted Answer

They are signaling proteins that coordinate immune cell communication and actions.

Question 7

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

Accepted Answer

Vascular changes → Leukocyte recruitment → Resolution

Question 8

A patient with a fever of 39°C is given ibuprofen. Which of the following best explains how ibuprofen reduces fever?

Accepted Answer

It inhibits the production of prostaglandins in the hypothalamus.

Question 9

Which of the following is a function of the complement system?

Accepted Answer

Tagging pathogens for phagocytosis (opsonization)

Question 10

Which of the following best describes the role of iron-binding proteins in innate immunity?

Accepted Answer

They limit the availability of free iron, restricting bacterial growth.

Question 11

A patient is diagnosed with chronic inflammation. Which of the following is a potential consequence of unregulated chronic inflammation?

Accepted Answer

Increased risk of atherosclerosis and certain cancers

Question 12

Which of the following best explains why a low-grade fever is considered beneficial during infection?

Accepted Answer

It enhances the antiviral effects of interferons and increases phagocyte efficiency.

Question 13

Which of the following is a feature of the skin that makes it an effective physical barrier?

Accepted Answer

It is enriched with proteins and lipids, forming a water-resistant layer.

Question 14

Which leukocyte is most likely to be elevated in a patient with an acute bacterial infection?

Accepted Answer

Neutrophils

Question 15

Which of the following is a correct statement about the classical pathway of complement activation?

Accepted Answer

It is triggered by antibodies bound to an invading agent.

Question 16

Which of the following best describes the function of defensins?

Accepted Answer

They are a class of antimicrobial peptides that rapidly kill invaders by inserting into target cell membranes.

Question 17

A patient with a genetic defect in regulators of complement activation (RCAs) is most likely to experience which of the following?

Accepted Answer

Uncontrolled complement activation leading to damage of self tissues

Question 18

Which of the following is a role of mast cells in the immune response?

Accepted Answer

They release histamine and play a role in allergies and fighting parasites.

Question 19

Which of the following best explains why doctors checked for hemochromatosis in a child with recurrent bacterial infections?

Accepted Answer

Hemochromatosis leads to increased iron availability, which can promote bacterial growth.

Question 20

Which of the following is a cardinal sign of inflammation that results from increased blood flow and vessel permeability?

Accepted Answer

Redness

Innate Immunity: Principles and Clinical Applications

Study Guide - Practice Questions