Question 1

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

Accepted Answer

Innate immunity is present from birth and does not change with repeated exposures, while adaptive immunity is acquired and improves with each exposure.

Question 2

Which cell type is responsible for the production of antibodies in the adaptive immune response?

Accepted Answer

Plasma cell

Question 3

A patient with a genetic defect in the C3 protein would most likely have problems with which immune process?

Accepted Answer

Opsonization, inflammation, and cell lysis

Question 4

Which of the following is a function of interferons?

Accepted Answer

Regulation of innate immunity and activation of antiviral proteins

Question 5

Which step in phagocytosis is blocked by Mycobacterium tuberculosis to avoid destruction by macrophages?

Accepted Answer

Fusion of phagosome with lysosome

Question 6

Which of the following best describes the role of opsonization in the immune response?

Accepted Answer

It coats pathogens with serum proteins to enhance phagocytosis.

Question 7

Which cytokine is primarily responsible for the recruitment of leukocytes to sites of infection?

Accepted Answer

Chemokine

Question 8

A patient develops a high fever after a bacterial infection. Which process is responsible for resetting the hypothalamic thermostat?

Accepted Answer

Release of prostaglandins by the hypothalamus

Question 9

Which Toll-like receptor (TLR) recognizes Lipid A, a component of Gram-negative bacterial cell walls?

Accepted Answer

TLR4

Question 10

Which of the following is NOT a typical sign of the acute inflammatory response?

Accepted Answer

Bradycardia

Question 11

Which pathway of complement activation is triggered by antibodies bound to antigens?

Accepted Answer

Classical pathway

Question 12

Which of the following best explains why Leishmania species can survive inside macrophages?

Accepted Answer

They block the digestion step after phagosome-lysosome fusion.

Question 13

Which of the following is a direct result of the formation of the membrane attack complex (MAC) during complement activation?

Accepted Answer

Lysis of the pathogen's cell membrane

Question 14

Which of the following is a pro-inflammatory cytokine that activates cytotoxic T lymphocytes?

Accepted Answer

Tumor necrosis factor

Question 15

A patient experiences a 'cytokine storm' during a severe viral infection. Which of the following best describes this phenomenon?

Accepted Answer

An excessive and maladaptive release of pro-inflammatory cytokines

Question 16

Which of the following is the correct sequence of events in phagocytosis?

Accepted Answer

Chemotaxis → Adherence → Ingestion → Fusion with lysosome → Digestion → Exocytosis

Question 17

Which of the following best describes the role of C3b in the complement cascade?

Accepted Answer

Acts as an opsonin to enhance phagocytosis

Question 18

Which of the following is a physical barrier that helps prevent microbial entry into the respiratory tract?

Accepted Answer

Ciliary escalator

Question 19

Which of the following is a function of colony-stimulating factors?

Accepted Answer

Stimulation of hematopoietic progenitor cell proliferation and differentiation

Question 20

A mutation in the gene encoding TLR4 would most likely impair the immune response to which type of pathogen?

Accepted Answer

Gram-negative bacteria

Host Defenses: Innate and Adaptive Immunity

Study Guide - Practice Questions

Study Guide - Flashcards