Question 1

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

Accepted Answer

The adaptive response is specific to particular antigens and has immunological memory, while the innate response is non-specific and lacks memory.

Question 2

A patient receives antibodies against a snake venom through an injection after being bitten. Which type of immunity is this an example of?

Accepted Answer

Artificially acquired passive immunity

Question 3

Which of the following statements about antigen-presenting cells (APCs) is correct?

Accepted Answer

APCs include dendritic cells, macrophages, and B cells, and they present antigens to T cells using MHC II molecules.

Question 4

Which antibody isotype is most abundant in human blood and can cross the placenta to provide immunity to the fetus?

Accepted Answer

IgG

Question 5

A patient is exposed to a pathogen for the first time. Which antibody isotype will be produced first during the primary immune response?

Accepted Answer

IgM

Question 6

Which of the following best explains why haptens alone do not trigger an immune response?

Accepted Answer

Haptens must be linked to a larger protein or polysaccharide to become immunogenic.

Question 7

Which of the following is a function of T helper 1 (TH1) cells?

Accepted Answer

Activate T cytotoxic cells, macrophages, and natural killer cells to destroy intracellular pathogens

Question 8

What is the main role of memory cells in adaptive immunity?

Accepted Answer

To provide a rapid and effective response upon secondary exposure to the same antigen

Question 9

Which of the following best describes the process of opsonization?

Accepted Answer

Antibodies coat antigens, enhancing their uptake and destruction by phagocytes.

Question 10

Which of the following is true regarding the activation of T cytotoxic cells?

Accepted Answer

They require two signals: TCR interaction with MHC I-antigen complex and co-stimulatory protein binding.

Question 11

A patient is exposed to the influenza virus for a second time. Which of the following best describes the expected antibody response?

Accepted Answer

A rapid and high titer of IgG with a small amount of IgM.

Question 12

Which of the following is a characteristic of artificially acquired active immunity?

Accepted Answer

It results from vaccination and leads to the formation of memory cells.

Question 13

Which of the following best describes the role of MHC I molecules in the immune response?

Accepted Answer

They present intracellular antigens to T cytotoxic cells.

Question 14

Which of the following is a correct statement about B cell activation?

Accepted Answer

Most B cells require T helper cells for full activation, especially for T-dependent antigens.

Question 15

Which of the following is a possible consequence of a failure in self-tolerance screening of T cells?

Accepted Answer

T cells may attack normal body cells, leading to autoimmune disease.

Question 16

Which of the following best explains why tissue transplants can be rejected by the recipient's immune system?

Accepted Answer

The recipient's immune system recognizes mismatched MHC proteins as foreign and mounts an immune response.

Question 17

Which of the following is a function of IgE antibodies?

Accepted Answer

They mediate allergic responses and help fight parasitic infections.

Question 18

Which of the following best describes the process of clonal expansion?

Accepted Answer

A single B or T cell divides to produce many identical cells that recognize the same epitope.

Question 19

Which of the following is true regarding superantigens?

Accepted Answer

They directly crosslink MHC II and TCR, causing a broad, nonspecific activation of T helper cells.

Adaptive Immunity: Principles and Mechanisms

Study Guide - Practice Questions