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 is slower to activate and highly specific.

Question 2

A patient with a genetic defect in their ability to produce antimicrobial peptides (AMPs) would most likely experience which of the following?

Accepted Answer

Decreased ability to directly kill a wide range of microbes, leading to increased susceptibility to infections.

Question 3

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

Accepted Answer

Directly producing antibodies against pathogens.

Question 4

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

Accepted Answer

It hydrolyzes bacterial cell walls, especially in Gram-positive bacteria.

Question 5

A patient presents with an acute bacterial infection. Which leukocyte would you expect to be elevated in their blood count?

Accepted Answer

Neutrophils

Question 6

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

Accepted Answer

Margination → Diapedesis → Chemotaxis

Question 7

Which of the following statements about the complement system is TRUE?

Accepted Answer

All complement pathways converge to activate C3, leading to opsonization, cytolysis, and inflammation.

Question 8

A bacterial pathogen produces siderophores. What is the primary function of these molecules?

Accepted Answer

To sequester iron from host iron-binding proteins.

Question 9

Which of the following is a cardinal sign of inflammation?

Accepted Answer

Redness

Question 10

Which cytokine family is primarily responsible for activating both innate and adaptive immune responses and stimulating hematopoiesis?

Accepted Answer

Interleukins (ILs)

Question 11

A patient with a fever has a body temperature of $$40.5^\circ C. $$According to clinical guidelines, what is the most appropriate next step?

Accepted Answer

Treat immediately, as this is a life-threatening high-grade fever.

Question 12

Which of the following best explains why chronic inflammation can be harmful?

Accepted Answer

It promotes tissue injury and is associated with diseases such as atherosclerosis and certain cancers.

Question 13

Which of the following is a function of Natural Killer (NK) cells in innate immunity?

Accepted Answer

Direct killing of virus-infected and tumor cells.

Question 14

Which of the following is a correct description of opsonization?

Accepted Answer

The tagging of pathogens with complement proteins to enhance phagocytosis.

Question 15

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

Accepted Answer

They act as signaling proteins that attract leukocytes to sites of infection or injury.

Question 16

A patient with neutropenia is most likely to have which of the following complications?

Accepted Answer

Increased risk of acute bacterial infections.

Question 17

Which of the following is a mechanical barrier of innate immunity?

Accepted Answer

Mucociliary escalator in the respiratory tract

Question 18

Which of the following is a correct outcome of complement activation?

Accepted Answer

Formation of a membrane attack complex (MAC) leading to cytolysis

Question 19

Which of the following best describes the function of dendritic cells in innate immunity?

Accepted Answer

They are highly phagocytic and present antigens to activate adaptive immune responses.

Question 20

Which of the following is a chemical barrier that limits pathogen survival on the skin?

Accepted Answer

Fatty acids in sweat

Innate Immunity: Principles and Mechanisms

Study Guide - Practice Questions