Question 1

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

Accepted Answer

Innate immunity is present at birth and lacks immunological memory, while adaptive immunity develops over time and has immunological memory.

Question 2

Which of the following is NOT a function of the skin in innate immunity?

Accepted Answer

Production of antibodies to target specific pathogens

Question 3

A patient presents with a bacterial skin infection. Which chemical defense of the skin is most likely compromised?

Accepted Answer

Lysozyme in sweat

Question 4

Which of the following best explains why the microbiome is considered a first-line defense against pathogens?

Accepted Answer

It creates an environment unfavorable to pathogens by competing for nutrients and producing antimicrobial compounds.

Question 5

Which of the following leukocytes is primarily responsible for releasing inflammatory chemicals and does NOT phagocytize pathogens?

Accepted Answer

Basophils

Question 6

A laboratory test shows an increased number of eosinophils in a patient’s blood. What is the most likely cause?

Accepted Answer

Allergic reaction or parasitic worm infection

Question 7

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

Accepted Answer

Chemotaxis, adhesion, ingestion, maturation, killing, elimination

Question 8

Which of the following best describes the role of Toll-like receptors (TLRs) in innate immunity?

Accepted Answer

They bind to pathogen-associated molecular patterns (PAMPs) and initiate defensive responses.

Question 9

Which pathway(s) can activate the complement system?

Accepted Answer

Classical, alternative, and lectin pathways

Question 10

A patient with a fever has a body temperature of 39°C. Which of the following is a likely benefit of this fever?

Accepted Answer

It inhibits the growth of some microbes and enhances the effects of interferons.

Question 11

Which of the following is a direct result of complement activation?

Accepted Answer

Lysis of foreign cells

Question 12

Which of the following best explains why acute inflammation is considered beneficial?

Accepted Answer

It is short-lived, promotes phagocyte migration, and facilitates tissue repair.

Question 13

Which of the following is a function of neutrophil extracellular traps (NETs)?

Accepted Answer

They bind to and kill bacteria extracellularly.

Question 14

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

Accepted Answer

They are protein molecules released by host cells to nonspecifically inhibit the spread of viral infections.

Question 15

A patient’s blood test shows an increased number of lymphocytes. Which type of infection is most likely present?

Accepted Answer

Viral infection

Question 16

Which of the following is a mechanism by which the microbiome prevents pathogen colonization?

Accepted Answer

By generating antimicrobial compounds

Question 17

Which of the following best describes the process of diapedesis?

Accepted Answer

The movement of leukocytes out of the blood vessels and into the tissues

Question 18

Which of the following is a characteristic sign of acute inflammation?

Accepted Answer

Redness, heat, swelling, and pain

Question 19

Which of the following is a function of sebum in innate immunity?

Accepted Answer

It lowers the skin pH to inhibit bacterial growth.

Question 20

Which of the following best explains why fever continues as long as pyrogens are present?

Accepted Answer

Pyrogens reset the hypothalamic thermostat to a higher temperature.

Innate Immunity: The Body’s First and Second Lines of Defense

Study Guide - Practice Questions