Question 1

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

Accepted Answer

Innate immunity responds quickly and identically to all threats, while adaptive immunity is specialized and forms immune memory.

Question 2

A patient is exposed to a new strain of influenza virus. Which immune cells are most likely to be activated first?

Accepted Answer

Neutrophils and macrophages

Question 3

Which of the following is NOT a function of physical barriers in the immune system?

Accepted Answer

Directly killing infected cells via cytotoxic T cells

Question 4

During a bacterial infection, which molecular pattern is most likely to trigger an innate immune response?

Accepted Answer

Pathogen-Associated Molecular Patterns (PAMPs)

Question 5

Which equation best represents the diversity of T cell receptors (TCRs) in the human body?

Accepted Answer

$$10^{8}$$

Question 6

A researcher uses flow cytometry to identify immune cells. Which marker is expressed on all T cells?

Accepted Answer

CD3

Question 7

Which of the following statements about immunological memory is correct?

Accepted Answer

Immunological memory allows for a quicker and stronger response upon reinfection.

Question 8

Which immune response type is most effective against extracellular bacteria and fungi?

Accepted Answer

Type 3 (or type 17)

Question 9

A patient with a tapeworm infection is likely to mount which type of adaptive immune response?

Accepted Answer

Type 2: mucosal and barrier immunity

Question 10

Which of the following best explains why vaccination is safer than variolation?

Accepted Answer

Vaccination uses attenuated agents that are less capable or incapable of causing disease.

Question 11

Which cell type is responsible for producing antibodies after activation?

Accepted Answer

B lymphocytes

Question 12

Which of the following is a limitation of the innate immune system?

Accepted Answer

It cannot distinguish between different pathogens.

Question 13

A commensal microorganism in the gut is most likely to:

Accepted Answer

Be neutral or beneficial to the host.

Question 14

Which of the following best describes the role of cytokines in the immune system?

Accepted Answer

Cytokines are small signaling proteins that induce immune responses and recruit adaptive immunity.

Question 15

Which scenario best illustrates the concept of immunological memory?

Accepted Answer

A person mounts a faster and stronger immune response upon reinfection with the same pathogen.

Question 16

Which of the following is true about T cell activation?

Accepted Answer

T cells are activated by sensor cells (antigen-presenting cells) presenting specific antigens.

Question 17

Which of the following best describes NETosis?

Accepted Answer

A process where neutrophils release extracellular traps made of de-condensed chromatin to damage pathogens.

Question 18

Which equation best represents the diversity of B cell receptors (BCRs) in the human body?

Accepted Answer

$$10^{10}$$

Question 19

A patient is reinfected with a virus after vaccination. Which cells are most likely to respond rapidly?

Accepted Answer

Memory T and B cells

Question 20

Which of the following best explains the depletion of local CD8+ intraepithelial lymphocytes (IELs) during type 2 immunity?

Accepted Answer

Driven by apoptotic cell death and purinergic receptor signaling triggered by T. mu-derived succinate.

Introduction to Immunology: Structure, Function, and Cellular Mechanisms

Study Guide - Practice Questions