Question 1

Which of the following best describes the main difference between innate and adaptive immunity?

Accepted Answer

Innate immunity targets a limited number of microbial structures, while adaptive immunity can recognize billions of different antigens.

Question 2

Which of the following is NOT a characteristic of adaptive immunity?

Accepted Answer

Immediate response to all pathogens

Question 3

A patient receives a kidney transplant. Which molecules are most important in determining whether the transplant will be accepted or rejected?

Accepted Answer

Major histocompatibility complex (MHC) antigens

Question 4

Which of the following statements about B cell receptors (BCRs) is TRUE?

Accepted Answer

Each B cell produces a single type of BCR, capable of recognizing only one epitope.

Question 5

Which class of antibody is most abundant in body secretions such as saliva and breast milk?

Accepted Answer

IgA

Question 6

A viral protein is synthesized inside a host cell. Which pathway will present its epitope to cytotoxic T cells?

Accepted Answer

The protein will be processed in the endoplasmic reticulum and presented on MHC class I molecules.

Question 7

Which of the following best explains why clonal deletion of T cells is necessary?

Accepted Answer

To eliminate T cells that react to self-antigens, preventing autoimmunity.

Question 8

Which of the following is a function of antibodies?

Accepted Answer

Activating complement and promoting inflammation

Question 9

A child receives antibodies from her mother through breast milk. This is an example of:

Accepted Answer

Naturally acquired passive immunity

Question 10

Which of the following cytokines is primarily responsible for signaling among leukocytes?

Accepted Answer

Interleukins (ILs)

Question 11

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

Accepted Answer

They regulate B cells and cytotoxic T cells by secreting cytokines.

Question 12

Which of the following is a property of exogenous antigens?

Accepted Answer

They include toxins and components of microbial cell walls, membranes, and flagella.

Question 13

Which of the following best explains why passive immunity is effective more quickly than active immunity?

Accepted Answer

Passive immunity involves the direct transfer of antibodies, providing immediate protection.

Question 14

Which of the following is TRUE regarding the secondary antibody immune response?

Accepted Answer

It is faster and produces more IgG antibodies than the primary response.

Question 15

Which of the following best describes the function of regulatory T lymphocytes?

Accepted Answer

They repress adaptive immune responses to prevent autoimmunity.

Question 16

Which of the following is a correct sequence of events in the activation of cytotoxic T cells?

Accepted Answer

Antigen presentation → Helper T cell differentiation → Clonal expansion → Self-stimulation

Question 17

Which of the following is a reason why exogenous epitopes are processed in vesicles rather than in the endoplasmic reticulum?

Accepted Answer

Exogenous antigens are internalized by phagocytosis and processed in vesicles for presentation on MHC class II molecules.

Question 18

Which of the following best describes the function of the RAG enzyme in B cell development?

Accepted Answer

It combines different variable region gene segments to generate antibody diversity.

Question 19

Which of the following is a function of memory T cells?

Accepted Answer

They persist in lymphoid tissues and respond rapidly upon subsequent exposure to the same antigen.

Adaptive Immunity: Mechanisms, Cells, and Molecular Basis

Study Guide - Practice Questions