Question 1

Which of the following best describes the dual nature of the adaptive immune system?

Accepted Answer

It is composed of humoral immunity, which targets freely circulating pathogens, and cellular immunity, which targets intracellular pathogens.

Question 2

A patient receives an injection of antibodies after exposure to rabies. What type of immunity is this?

Accepted Answer

Artificially acquired passive immunity

Question 3

Which immunoglobulin is most abundant in serum and can cross the placenta to protect the fetus?

Accepted Answer

IgG

Question 4

What is the primary function of the Fc (stem) region of an antibody?

Accepted Answer

It determines the antibody's class.

Question 5

Which process describes the coating of a pathogen with antibodies to enhance phagocytosis?

Accepted Answer

Opsonization

Question 6

A B cell recognizes and binds to a polysaccharide antigen without T cell help. This is an example of:

Accepted Answer

T-independent antigen response

Question 7

Which cell type is responsible for killing virus-infected cells by recognizing antigens presented with MHC class I molecules?

Accepted Answer

Cytotoxic T lymphocytes (CTLs)

Question 8

Which cytokine is primarily responsible for stimulating macrophage activity?

Accepted Answer

Interferon-gamma (IFN-\gamma)

Question 9

What is the main outcome of clonal selection in B cells?

Accepted Answer

Production of memory cells and plasma cells

Question 10

Which of the following best explains why a secondary immune response is faster and stronger than a primary response?

Accepted Answer

Memory cells generated during the primary response rapidly differentiate into plasma cells upon re-exposure.

Question 11

Which antibody class is primarily found in secretions and provides mucosal protection?

Accepted Answer

IgA

Question 12

A patient with a parasitic worm infection shows elevated levels of which antibody and which cell type?

Accepted Answer

IgE and eosinophils

Question 13

Which of the following is a function of T regulatory (Treg) cells?

Accepted Answer

Suppression of immune responses against self-antigens

Question 14

Which of the following best describes the role of M cells in the immune system?

Accepted Answer

They facilitate contact between antigens in the intestinal tract and immune cells.

Question 15

Which of the following is a correct sequence of events in the activation of a CD4+ T helper cell?

Accepted Answer

Antigen presentation by MHC II, costimulatory signal, TCR binding, cytokine production

Question 16

Which of the following is NOT a protective mechanism of antigen-antibody binding?

Accepted Answer

Induction of apoptosis in B cells

Question 17

A newborn receives antibodies from its mother through breast milk. This is an example of:

Accepted Answer

Naturally acquired passive immunity

Question 18

Which of the following best describes the function of natural killer (NK) cells?

Accepted Answer

They destroy cells that do not express MHC I, including virus-infected and tumor cells.

Question 19

Which cytokine is most directly involved in promoting inflammation?

Accepted Answer

Tumor necrosis factor-alpha (TNF-\alpha)

Question 20

Which of the following best explains the concept of clonal deletion?

Accepted Answer

It is the elimination of self-reactive lymphocytes during development.

Adaptive Immunity: Structure, Function, and Mechanisms

Study Guide - Practice Questions