Question 1

Which of the following best describes the primary function of innate (non-specific) immunity?

Accepted Answer

It acts as the body's first line of defense, responding quickly to a wide range of pathogens.

Question 2

Which type of leukocyte is most associated with killing cells infected by viruses and tumor cells?

Accepted Answer

Natural Killer (NK) cells

Question 3

A patient is exposed to a bacterial pathogen. Which step in the inflammatory response is most likely to occur first?

Accepted Answer

Release of histamine by mast cells

Question 4

Which of the following is NOT a function of the complement system?

Accepted Answer

Production of antibodies

Question 5

Which equation best represents the formation of the membrane attack complex (MAC) in the complement cascade?

Accepted Answer

$C5b + C6 + C7 + C8 + nC9 \rightarrow MAC$

Question 6

Which of the following best explains the difference between Class I and Class II MHC proteins?

Accepted Answer

Class I MHC presents endogenous antigens to cytotoxic T cells, while Class II MHC presents exogenous antigens to helper T cells.

Question 7

Which antibody subclass is most effective at crossing the placenta to provide passive immunity to a fetus?

Accepted Answer

IgG

Question 8

A person receives a flu vaccine. Which type of immunity is primarily being stimulated?

Accepted Answer

Adaptive immunity

Question 9

Which of the following is the best definition of an antigen?

Accepted Answer

A molecule that triggers an immune response

Question 10

Which process is responsible for the destruction of infected body cells by cytotoxic T cells?

Accepted Answer

Release of perforin and granzymes

Question 11

Which of the following best describes the role of helper T cells in the immune response?

Accepted Answer

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

Question 12

Which equation represents the activation of B cells by helper T cells?

Accepted Answer

$B_{cell} + T_{helper} \rightarrow B_{cell}^{activated}$

Question 13

Which of the following is a major histocompatibility complex (MHC) in humans?

Accepted Answer

HLA (Human Leukocyte Antigen)

Question 14

Which scenario best illustrates the concept of opsonization?

Accepted Answer

Antibodies bind to a pathogen, marking it for phagocytosis by macrophages.

Question 15

Which of the following is true regarding the difference between innate and adaptive immunity?

Accepted Answer

Adaptive immunity generates memory cells, while innate immunity does not.

Question 16

Which equation best represents the process of antibody-mediated neutralization of a pathogen?

Accepted Answer

$Antibody + Pathogen \rightarrow Neutralized\ Pathogen$

Question 17

Which of the following is most likely to occur if the complement system is deficient in C3 protein?

Accepted Answer

Decreased ability to opsonize pathogens and increased susceptibility to infections

Question 18

Which cell type is primarily responsible for antibody production?

Accepted Answer

Plasma cells

Question 19

Which of the following best describes the process of clonal selection in adaptive immunity?

Accepted Answer

Activation and proliferation of lymphocytes specific to an encountered antigen

Question 20

A patient with HIV has a low CD4+ T cell count. Which aspect of their immune response is most compromised?

Accepted Answer

Activation of B cells and cytotoxic T cells

Immunity and Immune System: Study Notes for Anatomy & Physiology

Study Guide - Practice Questions