Question 1

Which of the following best describes the difference between the primary and secondary immune responses to the same antigen?

Accepted Answer

The secondary response is faster and stronger than the primary response due to the presence of memory cells.

Question 2

A patient is infected with a virus that replicates inside host cells. Which branch of the adaptive immune system is primarily responsible for eliminating these infected cells?

Accepted Answer

Cell-mediated immunity, primarily involving cytotoxic T lymphocytes.

Question 3

Which of the following is NOT considered a secondary lymphoid organ?

Accepted Answer

Bone marrow

Question 4

What is the specific region of an antigen that is recognized and bound by an antibody called?

Accepted Answer

Epitope

Question 5

Which of the following best describes the structure of an antibody molecule?

Accepted Answer

Two identical heavy chains and two identical light chains forming a Y-shaped molecule

Question 6

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

Accepted Answer

Antigenic variation

Question 7

A patient receives a vaccine and later is exposed to the same pathogen. Which class of antibody is most likely to be produced in the greatest quantity during the secondary response?

Accepted Answer

IgG

Question 8

During clonal selection, what happens to a B cell that binds to its specific antigen?

Accepted Answer

It is activated, proliferates, and differentiates into plasma and memory cells.

Question 9

Which process increases the binding strength (affinity) of antibodies for their antigen during an immune response?

Accepted Answer

Affinity maturation

Question 10

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

Accepted Answer

They activate B cells and cytotoxic T cells by releasing cytokines.

Question 11

Which of the following statements about Major Histocompatibility Complex (MHC) molecules is correct?

Accepted Answer

MHC class I molecules present endogenous antigens to cytotoxic T cells.

Question 12

A patient with a genetic defect cannot produce functional B cells. Which of the following immune responses would be most impaired?

Accepted Answer

Production of antibodies against extracellular bacteria

Question 13

Which of the following mechanisms is responsible for generating the diversity of antibody molecules?

Accepted Answer

Gene rearrangement, imprecise joining, and combinatorial associations

Question 14

Which of the following best describes a T-independent antigen?

Accepted Answer

An antigen that can activate B cells without T cell help

Question 15

Which of the following is a key difference between natural killer (NK) cells and cytotoxic T lymphocytes (CTLs)?

Accepted Answer

NK cells can kill cells lacking MHC I, while CTLs require antigen presentation by MHC I.

Question 16

During the process of positive and negative selection in the thymus, what is the main purpose?

Accepted Answer

To eliminate T cells that do not recognize self-MHC or that react strongly to self-antigens

Question 17

A researcher is studying the process of class switching in B cells. Which of the following best describes this process?

Accepted Answer

A B cell switches from producing IgM to another antibody class, such as IgG, while retaining antigen specificity.

Question 18

Which of the following equations best represents the relationship between the number of possible antibody specificities ($$N$$), the number of variable ($$V$$), diversity ($$D$$), and joining ($$J) $$gene segments, assuming random combination?

Accepted Answer

$$N = V 	imes D 	imes J$$

Question 19

A patient is exposed to a bacterial toxin for the first time. Which antibody class is produced first in response to this exposure?

Accepted Answer

IgM

Question 20

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

Accepted Answer

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

The Adaptive Immune Response: Study Notes

Study Guide - Practice Questions

Study Guide - Flashcards