Question 1

Which of the following best describes the role of helper T cells in the adaptive immune response?

Accepted Answer

They activate both humoral and cell-mediated immune responses by stimulating B cells and cytotoxic T cells.

Question 2

A patient receives a kidney transplant from a non-identical donor. Which immune system component is most likely responsible for transplant rejection?

Accepted Answer

Cytotoxic T cells recognizing non-self MHC molecules on donor cells.

Question 3

Which process is illustrated when antibodies bind to a virus and prevent it from entering host cells?

Accepted Answer

Neutralization

Question 4

What is the main function of memory B cells in the adaptive immune response?

Accepted Answer

To rapidly initiate a stronger and faster antibody response upon secondary exposure to the same antigen.

Question 5

Which of the following best explains why a person with type A blood cannot safely receive type B blood?

Accepted Answer

Type A blood contains anti-B antibodies that react with B antigens on transfused cells, causing lysis.

Question 6

Which of the following is a key difference between active and passive immunity?

Accepted Answer

Active immunity is generated by the individual's own immune response to infection or vaccination.

Question 7

A cytotoxic T cell recognizes and binds to an infected cell. What must be present on the infected cell's surface for this recognition to occur?

Accepted Answer

Class I MHC molecule presenting a foreign antigen

Question 8

Which of the following best describes the mechanism by which the complement system destroys foreign cells?

Accepted Answer

By forming pores in the cell membrane, causing water and ions to rush in and lyse the cell

Question 9

Why are booster vaccine doses necessary for maintaining immunity against certain diseases such as COVID-19?

Accepted Answer

Booster doses replenish stores of memory cells, ensuring a strong secondary immune response.

Question 10

Which of the following is a real-world application of monoclonal antibodies?

Accepted Answer

They are used in home pregnancy tests to detect human chorionic gonadotropin (hCG).

Question 11

A child is born without a thymus gland. Which immune function would be most severely affected?

Accepted Answer

Activation of cytotoxic T cells and helper T cells

Question 12

Which of the following best describes the process of opsonization?

Accepted Answer

Antibodies bind to antigens on pathogens, marking them for phagocytosis by macrophages and neutrophils.

Question 13

Which of the following is true regarding the humoral immune response?

Accepted Answer

It involves the secretion of antibodies by plasma cells to neutralize or eliminate pathogens in body fluids.

Question 14

Which protein on the surface of helper T cells binds to class II MHC molecules, stabilizing the interaction with antigen-presenting cells?

Accepted Answer

CD4

Question 15

What is the main advantage of mRNA vaccines over traditional protein-based vaccines?

Accepted Answer

mRNA vaccines can be produced and modified more rapidly to target new viral strains.

Question 16

Which of the following best explains why a second treatment with antivenin can sometimes cause a harmful side effect?

Accepted Answer

The recipient's immune system may recognize the foreign antibodies in antivenin as antigens and mount an immune response.

Question 17

Which of the following is a direct result of the activation of the complement system by antibodies bound to a foreign cell?

Accepted Answer

A membrane attack complex forms, creating pores that cause the cell to lyse.

Question 18

Which of the following best describes the role of cytokines in the adaptive immune response?

Accepted Answer

Cytokines are signaling molecules that promote the activation and proliferation of immune cells.

Question 19

Which of the following is a consequence of widespread vaccine hesitancy in a population?

Accepted Answer

Higher rates of infection and increased risk of outbreaks of preventable diseases.

Question 20

Which of the following best explains why a person with type O blood is considered a universal donor?

Accepted Answer

Type O blood lacks A and B antigens, so it is not recognized as foreign by recipients with other blood types.

Adaptive Immunity: Mechanisms and Applications

Study Guide - Practice Questions