Question 1

Which of the following best describes the role of Major Histocompatibility Complex (MHC) class II molecules in the immune response?

Accepted Answer

They are found on antigen-presenting cells and present processed antigens to T helper cells.

Question 2

A patient receives an injection of preformed antibodies after a snake bite. This is an example of which type of immunity?

Accepted Answer

Artificial passive immunity

Question 3

Which of the following statements about clonal selection is CORRECT?

Accepted Answer

Clonal selection occurs after an antigen binds to a lymphocyte with a matching receptor, leading to proliferation of that clone.

Question 4

Which immunoglobulin class is most prevalent in serum and is responsible for long-term immunity and memory antibody responses?

Accepted Answer

IgG

Question 5

A small molecule that is not immunogenic by itself but can elicit an immune response when attached to a larger carrier is called a:

Accepted Answer

Hapten

Question 6

Which of the following is a function of the Fc region of an antibody?

Accepted Answer

Fixing complement and binding to phagocyte receptors

Question 7

A vaccine is developed using only the purified surface protein of a virus. This type of vaccine is best classified as a:

Accepted Answer

Acellular (subunit) vaccine

Question 8

Which of the following best explains why live, attenuated vaccines often provide longer-lasting immunity than killed vaccines?

Accepted Answer

They stimulate both B cell and T cell responses by mimicking natural infection.

Question 9

Which cell type is primarily responsible for destroying virus-infected cells and cancer cells by releasing perforins and granzymes?

Accepted Answer

Cytotoxic T cells (CD8+)

Question 10

Which of the following best describes the process of opsonization?

Accepted Answer

Antibodies coat microbes, making them more easily recognized and ingested by phagocytes.

Question 11

Which cytokine is secreted by antigen-presenting cells to activate T helper cells during antigen presentation?

Accepted Answer

Interleukin-1 (IL-1)

Question 12

A patient with a genetic defect in MHC class I molecules would have the greatest impairment in which immune function?

Accepted Answer

Destruction of virus-infected cells by cytotoxic T cells

Question 13

Which of the following is TRUE regarding the antigen-binding sites of antibodies?

Accepted Answer

They are identical on both arms of the antibody molecule.

Question 14

Which of the following best describes the principle of herd immunity?

Accepted Answer

Immune individuals reduce the likelihood of pathogen transmission, protecting non-immune individuals.

Question 15

Which of the following is a characteristic of superantigens?

Accepted Answer

They provoke an overwhelming immune response by activating large numbers of T cells regardless of specificity.

Question 16

Which immunoglobulin class is primarily responsible for the first antibody response to an antigen and is a pentamer in structure?

Accepted Answer

IgM

Question 17

A child receives IgG antibodies from the mother through the placenta. This is an example of:

Accepted Answer

Natural passive immunity

Question 18

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

Accepted Answer

Memory B and T cells are rapidly activated upon re-exposure to the antigen.

Question 19

Which of the following is NOT a requirement for an effective vaccine?

Accepted Answer

It must require frequent, high-dose boosters.

Question 20

Which of the following best describes the process of agglutination?

Accepted Answer

Antibodies cross-link cells or particles into large clumps.

Adaptive (Specific) Immunity: Mechanisms, Cells, and Applications

Study Guide - Practice Questions