Question 1

Which of the following best describes the process by which T-cells distinguish self from non-self antigens in the thymus?

Accepted Answer

T-cells undergo positive and negative selection, eliminating those that react strongly to self-antigens.

Question 2

Which molecule is considered the most immunogenic among the following: proteins, polysaccharides, lipids, nucleic acids?

Accepted Answer

Proteins

Question 3

What is the primary function of MHC class I molecules in the immune response?

Accepted Answer

Present endogenous antigens to cytotoxic T-cells ($$CD8^+)$$

Question 4

A patient receives a vaccine containing inactivated virus. Which type of immunity is primarily induced?

Accepted Answer

Artificially acquired active immunity

Question 5

Which of the following best explains why secondary immune responses are faster and stronger than primary responses?

Accepted Answer

Memory cells generated during the primary response recognize the antigen and mount a rapid response.

Question 6

Which of the following is NOT a function of cytotoxic T-cells ($$CD8^+$$)?

Accepted Answer

Secretion of antibodies

Question 7

Which process describes the elimination of self-reactive lymphocytes during development?

Accepted Answer

Clonal deletion

Question 8

Which antibody isotype is most effective at activating the classical complement pathway?

Accepted Answer

IgM

Question 9

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

Accepted Answer

Naturally acquired passive immunity

Question 10

Which of the following best describes the role of antigen-presenting cells (APCs) in the immune response?

Accepted Answer

They process and present antigens to T-cells, initiating adaptive immunity.

Question 11

Which of the following is a key difference between MHC class I and MHC class II molecules?

Accepted Answer

MHC class I presents antigens to $$CD8^+ T-$$cells, while MHC class II presents antigens to $$CD4^+ T-$$cells.

Question 12

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

Accepted Answer

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

Question 13

Which process is responsible for the proliferation and differentiation of B-cells after activation?

Accepted Answer

Clonal expansion

Question 14

Which of the following is a function of helper T-cells ($$CD4^+$$)?

Accepted Answer

Secretion of cytokines to activate B-cells and other immune cells

Question 15

Which of the following best describes the process of opsonization?

Accepted Answer

Coating of pathogens with antibodies to enhance phagocytosis

Question 16

Which of the following is NOT a characteristic of antigens?

Accepted Answer

They are always proteins.

Question 17

Which of the following is a real-world example of artificially acquired passive immunity?

Accepted Answer

Receiving antivenom after a snake bite

Question 18

Which of the following best explains why IgE antibodies are important in allergic reactions?

Accepted Answer

IgE binds to mast cells and basophils, triggering histamine release upon antigen exposure.

Question 19

Which step is necessary for T-dependent activation of B-cells?

Accepted Answer

Interaction with helper T-cells ($$CD4^+) $$via antigen presentation

Question 20

Which of the following best describes the difference between primary and secondary lymphoid organs?

Accepted Answer

Primary lymphoid organs are sites of lymphocyte development; secondary lymphoid organs are sites of immune activation.

Immunology: Key Concepts and Mechanisms in Microbiology

Study Guide - Practice Questions