$$\text{Antibody titer} = \frac{\text{Concentration of antibody}}{\text{Volume of serum}}$$

Question 1

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

Accepted Answer

They enable a rapid and more intense immune response upon subsequent exposure to the same antigen.

Question 2

A patient receives a vaccine containing inactivated bacterial toxins. Which type of immunity is being induced?

Accepted Answer

Artificially acquired active immunity

Question 3

Which immunoglobulin class is primarily responsible for opsonization and can cross the placenta to provide immunity to a fetus?

Accepted Answer

IgG

Question 4

What is the role of the major histocompatibility complex (MHC) in adaptive immunity?

Accepted Answer

It enables the host to distinguish between self and non-self antigens.

Question 5

Which equation best represents antibody affinity?

Accepted Answer

$$K_a = \frac{[Ab-Ag]}{[Ab][Ag]}$$

Question 6

A newborn receives antibodies from breast milk. What type of immunity is this?

Accepted Answer

Naturally acquired passive immunity

Question 7

Which of the following is TRUE regarding T-cell activation?

Accepted Answer

Signal 2 involves the interaction between B7 (CD80) on the APC and CD28 on the T cell.

Question 8

Which immunoglobulin class is most abundant in serum and is involved in secondary immune responses?

Accepted Answer

IgG

Question 9

What is the primary mechanism by which cytotoxic T lymphocytes (CTLs) destroy infected host cells?

Accepted Answer

Release of perforin and granzymes to induce apoptosis

Question 10

Which process contributes most to the diversity of antibodies produced by B cells?

Accepted Answer

Somatic hypermutation and combinatorial joining

Question 11

A patient experiences a rapid, severe allergic reaction after exposure to bee venom. Which hypersensitivity type is this?

Accepted Answer

Type I hypersensitivity

Question 12

Which immunoglobulin class is primarily involved in agglutination and is produced first during a primary immune response?

Accepted Answer

IgM

Question 13

Which equation best represents the antibody titer?

Accepted Answer

$$	ext{Antibody titer} = \frac{	ext{Concentration of antibody}}{	ext{Volume of serum}}$$

Question 14

Which of the following is a characteristic of Type IV hypersensitivity?

Accepted Answer

It is a delayed-type hypersensitivity mediated by T cells.

Question 15

What is the primary function of the Fc region of an antibody?

Accepted Answer

It mediates binding to immune cell receptors and initiates complement activation.

Question 16

Which of the following best describes the clonal selection theory?

Accepted Answer

Only B cells that recognize and bind a specific antigen are stimulated to proliferate and form clones.

Question 17

A patient receives antitoxin produced in a horse to treat a bacterial infection. Which type of immunity is this?

Accepted Answer

Artificially acquired passive immunity

Question 18

Which of the following is TRUE about MHC class I molecules?

Accepted Answer

They are present on all nucleated cells and present endogenous antigens to CD8+ T cells.

Question 19

Which mechanism is responsible for the rapid and efficient secondary antibody response?

Accepted Answer

Presence of memory B cells that quickly differentiate into plasma cells

Question 20

Which of the following is a consequence of immune complex formation in Type III hypersensitivity?

Accepted Answer

Accumulation of immune complexes leading to inflammation and tissue damage

Adaptive Immunity: Mechanisms, Cells, and Clinical Implications

Study Guide - Practice Questions