Question 1

Which of the following best describes the role of the major histocompatibility complex (MHC) in adaptive immunity?

Accepted Answer

MHC molecules hold and present antigenic epitopes to immune cells for recognition.

Question 2

A patient receives antibodies from an immune donor after exposure to a toxin. Which type of acquired immunity is this?

Accepted Answer

Artificially acquired passive immunity

Question 3

Which of the following is a property unique to adaptive immunity and not shared with innate immunity?

Accepted Answer

Inducibility

Question 4

Which class of antibody is most abundant in serum during a secondary immune response?

Accepted Answer

IgG

Question 5

A cytotoxic T cell recognizes a virally infected cell. Which molecules are involved in this recognition?

Accepted Answer

TCR and MHC class I

Question 6

Which process ensures that lymphocytes do not mount immune responses against the body’s own tissues?

Accepted Answer

Clonal deletion

Question 7

Which of the following best describes an epitope?

Accepted Answer

A three-dimensional region on an antigen recognized by lymphocytes

Question 8

Which of the following is NOT a function of antibodies?

Accepted Answer

Direct killing of intracellular viruses

Question 9

What is the main function of regulatory T lymphocytes?

Accepted Answer

Promote tolerance to self-antigens and repress immune responses

Question 10

Which of the following best explains why memory cells are important in adaptive immunity?

Accepted Answer

They allow for a faster and more effective response upon re-exposure to the same antigen.

Question 11

Which cytokine is primarily responsible for signaling among leukocytes?

Accepted Answer

Interleukin (IL)

Question 12

Which of the following is true regarding the diversity of B cell receptors (BCRs)?

Accepted Answer

BCR diversity is generated by random recombination of gene segments (V, D, J) by the RAG enzyme.

Question 13

Which pathway is used by cytotoxic T cells to induce apoptosis in target cells?

Accepted Answer

Perforin-granzyme pathway

Question 14

Which of the following best describes the difference between exogenous and endogenous antigens?

Accepted Answer

Exogenous antigens are toxins or components of microbes outside cells, while endogenous antigens are produced by microbes inside cells.

Question 15

Which of the following is a characteristic of the secondary immune response compared to the primary immune response?

Accepted Answer

It is faster and produces more IgG antibodies.

Question 16

Which of the following is NOT a secondary lymphoid organ?

Accepted Answer

Thymus

Question 17

Which of the following best describes the function of chemokines?

Accepted Answer

They are chemotactic cytokines that signal leukocytes to move.

Question 18

Which of the following is true about MHC class II molecules?

Accepted Answer

They are found only on antigen-presenting cells such as macrophages, B cells, and dendritic cells.

Question 19

Which of the following is the first antibody class produced during a primary immune response?

Accepted Answer

IgM

Question 20

A patient with a genetic defect in the RAG enzyme would most likely have which of the following problems?

Accepted Answer

Reduced diversity of BCRs and TCRs, leading to severe immunodeficiency

Adaptive Immunity: Mechanisms, Cells, and Responses

Study Guide - Practice Questions