Question 1

Which of the following best describes the difference between innate and adaptive immune defenses?

Accepted Answer

Innate defenses are nonspecific, always ready, and have no memory, while adaptive defenses are specific, systemic, and produce memory.

Question 2

A patient receives a deep cut that becomes red, swollen, hot, and painful. Which process is primarily responsible for these symptoms?

Accepted Answer

Inflammation

Question 3

Which of the following is NOT a component of the first line of innate defense?

Accepted Answer

Natural killer cells

Question 4

What is the primary function of opsonization in the immune response?

Accepted Answer

To coat pathogens with molecules that enhance phagocytosis

Question 5

Which complement protein is split into two active pieces to initiate the final activation of the complement system?

Accepted Answer

C3

Question 6

What is the role of membrane attack complexes (MACs) in the immune response?

Accepted Answer

They insert into target cell membranes, forming pores that cause cell lysis.

Question 7

Which of the following best describes the process of phagocytosis?

Accepted Answer

Phagocytes adhere to pathogens, engulf them into a vesicle, fuse with a lysosome, digest the material, and expel indigestible debris.

Question 8

Which of the following is a hallmark and most important mechanism of the second line of innate defense?

Accepted Answer

Inflammation

Question 9

A virus-infected cell releases interferons. What is the primary effect of these interferons on neighboring cells?

Accepted Answer

They stimulate neighboring cells to produce antiviral proteins that inhibit viral replication.

Question 10

Which of the following is a correct sequence of events during inflammation after tissue injury?

Accepted Answer

Release of inflammatory chemicals → Vasodilation and increased vascular permeability → Phagocyte mobilization

Question 11

Which of the following is a function of natural killer (NK) cells?

Accepted Answer

They induce apoptosis in cells lacking self-MHC markers by releasing perforin and granzymes.

Question 12

Which of the following best explains why swelling (edema) occurs during inflammation?

Accepted Answer

Increased vascular permeability allows protein-rich fluid to leak into tissues, increasing osmotic pressure and drawing more fluid out of vessels.

Question 13

Which of the following is a direct result of complement activation?

Accepted Answer

Formation of membrane attack complexes (MACs) that lyse target cells

Question 14

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

Accepted Answer

Increased susceptibility to bacterial infections due to impaired lysis and opsonization

Question 15

Which of the following is a key difference between the classical and alternative pathways of complement activation?

Accepted Answer

The classical pathway is activated by antibodies coating the target cell, while the alternative pathway is activated spontaneously on microbial surfaces.

Question 16

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

Accepted Answer

Fever increases metabolic rate, inhibits replication of bacteria and viruses, and causes the liver and spleen to sequester iron and zinc.

Chapter 21: The Immune System – Innate and Adaptive Body Defenses

Study Guide - Practice Questions

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