Question 1

Which of the following best describes the primary function of B cells in adaptive immunity?

Accepted Answer

B cells produce antibodies that bind to specific antigens, targeting them for destruction.

Question 2

A patient receives an injection of preformed antibodies against rabies after being bitten by a rabid animal. Which type of adaptive immunity is this?

Accepted Answer

Artificially acquired passive immunity

Question 3

Which immunoglobulin class is most abundant in serum and is capable of crossing the placenta to protect the fetus?

Accepted Answer

IgG

Question 4

What is the role of the variable (v) region of an antibody molecule?

Accepted Answer

It binds to specific epitopes on antigens.

Question 5

A child develops immunity to measles after recovering from the infection. Which type of immunity is this?

Accepted Answer

Naturally acquired active immunity

Question 6

Which of the following is TRUE regarding T-dependent antigen activation of B cells?

Accepted Answer

Both B and T cells must recognize the antigen, and cytokines from T helper cells activate B cells.

Question 7

Which process ensures that self-reactive B cells are eliminated during development?

Accepted Answer

Clonal deletion

Question 8

A patient with a parasitic worm infection experiences an allergic reaction. Which immunoglobulin is most likely involved?

Accepted Answer

IgE

Question 9

Which of the following is a function of cytotoxic T lymphocytes (CTLs)?

Accepted Answer

Induce apoptosis in virus-infected or tumor cells by releasing perforin and granzymes

Question 10

What is the significance of the 'memory' aspect of adaptive immunity?

Accepted Answer

It results in a faster and more effective response upon subsequent exposure to the same antigen.

Question 11

Which of the following best describes the role of MHC class II molecules?

Accepted Answer

They present exogenous antigens to T helper cells on antigen-presenting cells.

Question 12

Which mechanism is used by antibodies to enhance phagocytosis of pathogens?

Accepted Answer

Opsonization

Question 13

A laboratory test measures the antibody titer in a patient's serum. What does a high antibody titer indicate?

Accepted Answer

The patient has a strong humoral immune response, possibly due to recent exposure or vaccination.

Question 14

Which cytokine is primarily involved in activating macrophages and cells related to delayed hypersensitivity?

Accepted Answer

IFN-\gamma

Question 15

Which immunoglobulin class is most effective at causing agglutination and is the first antibody released during an infection?

Accepted Answer

IgM

Question 16

A patient with an autoimmune disease is found to have an overproduction of cytokines. What is the likely consequence?

Accepted Answer

Cytokine storm leading to excessive inflammation

Question 17

Which cell type is NOT stimulated by antigen but can destroy virus-infected cells and tumor cells by detecting the absence of MHC class I molecules?

Accepted Answer

Natural killer (NK) cell

Question 18

Which of the following is a correct equation for the valence of a pentameric IgM antibody?

Accepted Answer

$$	ext{Valence} = 10$$

Question 19

Which process describes the shift from an initial IgM response to a later IgG, IgE, or IgA response during secondary exposure to an antigen?

Accepted Answer

Class switching

Question 20

A patient is exposed to pollen, which triggers an immune response. Which term best describes pollen in this context?

Accepted Answer

Antigen

Adaptive Immunity: Specific Defenses of the Host

Study Guide - Practice Questions