Question 1

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

Accepted Answer

Innate immunity provides a rapid, non-specific response to pathogens, while adaptive immunity develops more slowly and is highly specific.

Question 2

A patient with a genetic defect in Toll-like receptors (TLRs) would most likely have which of the following problems?

Accepted Answer

Reduced ability to recognize pathogen-associated molecular patterns (PAMPs), leading to impaired activation of innate immune responses.

Question 3

Which of the following is NOT a physical factor of the first line of defense?

Accepted Answer

Lysozyme

Question 4

How do normal microbiota contribute to innate immunity?

Accepted Answer

They compete with pathogens for nutrients and attachment sites, and may produce substances harmful to pathogens.

Question 5

Which of the following cells is primarily responsible for phagocytosis during the early stages of infection?

Accepted Answer

Neutrophils

Question 6

A patient presents with a wound that is red, swollen, hot, and painful. Which of the following best explains the underlying mechanism for these symptoms?

Accepted Answer

Release of histamine causing vasodilation and increased vascular permeability.

Question 7

Which of the following best describes the process of diapedesis?

Accepted Answer

The movement of phagocytes from blood vessels into surrounding tissues.

Question 8

Which of the following is a chemical factor of the first line of defense that destroys bacterial cell walls?

Accepted Answer

Lysozyme

Question 9

Which complement pathway is initiated by antigen-antibody complexes?

Accepted Answer

Classical pathway

Question 10

A bacterial infection triggers the release of cytokines that act on the hypothalamus to increase body temperature. Which molecule mediates this effect?

Accepted Answer

Prostaglandins

Question 11

Which of the following is a possible outcome of complement activation?

Accepted Answer

Cytolysis, inflammation, and opsonization

Question 12

Which of the following best describes the role of interferons in innate immunity?

Accepted Answer

They induce uninfected cells to produce antiviral proteins that inhibit viral replication.

Question 13

Which of the following iron-binding proteins is found in human blood plasma and helps limit bacterial growth by sequestering iron?

Accepted Answer

Transferrin

Question 14

A patient with chronic inflammation is most likely to experience which of the following tissue repair outcomes?

Accepted Answer

Fibrosis leading to scar formation

Question 15

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

Accepted Answer

It enhances phagocytosis by coating pathogens with molecules that promote binding to phagocytes.

Question 16

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

Accepted Answer

Chemotaxis → Adherence → Ingestion → Digestion

Question 17

Which of the following best explains why fever can be beneficial during infection?

Accepted Answer

It increases the rate of phagocytosis and inhibits the growth of some pathogens.

Question 18

Which of the following is a key feature of antimicrobial peptides?

Accepted Answer

They disrupt microbial membranes and have broad-spectrum activity.

Question 19

Which of the following best describes the role of the lymphatic system in immunity?

Accepted Answer

It returns interstitial fluid to the bloodstream and provides sites for immune cell activation.

Question 20

A patient is given a probiotic supplement after antibiotic therapy. What is the most likely benefit of this intervention?

Accepted Answer

It helps restore the normal microbiota, reducing the risk of opportunistic infections.

Innate Immunity: Nonspecific Defenses of the Host

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