Question 1

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

Accepted Answer

Innate immunity is nonspecific and provides immediate defense, while adaptive immunity is specific and develops memory after exposure.

Question 2

A patient receives a kidney transplant from a genetically unrelated donor. Which type of graft is this, and what is the main immune concern?

Accepted Answer

Allograft; risk of rejection due to MHC incompatibility

Question 3

Which of the following is a function of the complement system in innate immunity?

Accepted Answer

Forming membrane attack complexes (MAC) that lyse bacterial cells

Question 4

A child is exposed to chickenpox and develops immunity. Which type of immunity is this, and what is the main feature?

Accepted Answer

Naturally acquired active immunity; long-lasting memory due to antibody production

Question 5

Which antibody class is most abundant in plasma and can cross the placenta to provide passive immunity to the fetus?

Accepted Answer

IgG

Question 6

A person with a genetic defect in adenosine deaminase (ADA) is unable to produce functional B and T cells. What is the most likely diagnosis?

Accepted Answer

Severe combined immunodeficiency (SCID)

Question 7

Which of the following best explains the process of opsonization?

Accepted Answer

Antibodies or complement proteins coat pathogens, enhancing phagocytosis by acting as 'handles' for phagocytes.

Question 8

Which of the following is NOT a cardinal sign of acute inflammation?

Accepted Answer

Fever

Question 9

A patient develops a rash after using a new detergent. The reaction is slow to develop and involves T cells. What type of hypersensitivity is this?

Accepted Answer

Delayed (Type IV) hypersensitivity

Question 10

Which of the following best describes the role of helper T (TH) cells in the immune response?

Accepted Answer

They activate both B cells and other T cells, and secrete cytokines to recruit immune cells.

Question 11

Which of the following is a real-life example of passive, artificially acquired humoral immunity?

Accepted Answer

Receiving an injection of gamma globulin after exposure to hepatitis

Question 12

Which of the following is the correct sequence of events in phagocytosis?

Accepted Answer

Recognition, adherence, phagosome formation, fusion with lysosome, digestion, exocytosis

Question 13

Which of the following best describes the mechanism by which cytotoxic T cells destroy infected cells?

Accepted Answer

They release perforins and granzymes to induce apoptosis in target cells.

Question 14

A patient receives a mismatched blood transfusion and develops a reaction involving antibody-mediated lysis of red blood cells. Which type of hypersensitivity is this?

Accepted Answer

Cytotoxic (Type II) hypersensitivity

Question 15

Which of the following is NOT an antigen-presenting cell (APC)?

Accepted Answer

T lymphocyte

Question 16

Which of the following best explains why haptens can cause allergic reactions?

Accepted Answer

Haptens become immunogenic only when they bind to body proteins, forming a complex recognized as foreign.

Question 17

Which of the following is a benefit of moderate fever during infection?

Accepted Answer

It increases the metabolic rate, speeding up tissue repair.

Question 18

Which of the following is the main reason why autoimmune diseases occur?

Accepted Answer

The immune system fails to recognize self-antigens and attacks the body’s own tissues.

Question 19

Which of the following best describes the role of MHC proteins in the immune system?

Accepted Answer

They are self-antigens that help the immune system distinguish self from non-self.

Question 20

Which of the following is a real-life example of artificially acquired active immunity?

Accepted Answer

Receiving a vaccine for influenza

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

Study Guide - Practice Questions

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