Question 1

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

Accepted Answer

It digests the peptidoglycan layer of bacterial cell walls, leading to cell lysis.

Question 2

A patient presents with an increased number of eosinophils in their blood. Which of the following is the most likely cause?

Accepted Answer

A parasitic worm infection

Question 3

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

Accepted Answer

Directly producing antibodies against pathogens

Question 4

Which of the following best explains why humans are resistant to many plant and animal pathogens?

Accepted Answer

Human cells lack the correct chemical receptors required by these pathogens.

Question 5

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

Accepted Answer

Chemotaxis → Adhesion → Ingestion → Maturation → Killing → Elimination

Question 6

Which of the following statements about the complement system is TRUE?

Accepted Answer

It can be activated by three pathways: classical, alternative, and lectin.

Question 7

A mutation that prevents the production of sebum would most likely result in which of the following?

Accepted Answer

Increased susceptibility to skin infections due to higher skin pH

Question 8

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

Accepted Answer

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

Question 9

Which of the following is a direct effect of acute inflammation at the site of tissue injury?

Accepted Answer

Increased permeability of blood vessels, allowing phagocytes to enter the tissue

Question 10

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

Accepted Answer

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

Question 11

A patient with a genetic defect in neutrophil function would most likely have difficulty with which of the following?

Accepted Answer

Phagocytosis and formation of neutrophil extracellular traps (NETs)

Question 12

Which of the following is a function of natural killer (NK) cells in innate immunity?

Accepted Answer

They secrete toxins onto the surface of virally infected cells and tumors.

Question 13

Which of the following best describes the role of interferons in the innate immune response?

Accepted Answer

They are proteins released by host cells to inhibit the spread of viral infections.

Question 14

Which of the following is a characteristic of chronic inflammation?

Accepted Answer

It is long-lasting and can cause tissue damage leading to disease.

Question 15

Which of the following best explains the function of dendritic cells in the epidermis?

Accepted Answer

They phagocytize pathogens that penetrate the skin.

Question 16

Which of the following is a correct statement about the role of antimicrobial peptides in innate immunity?

Accepted Answer

They are present in skin, mucous membranes, and neutrophils and act against a variety of microbes.

Question 17

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

Accepted Answer

Formation of the membrane attack complex (MAC) leading to cell lysis

Question 18

A patient with a deficiency in NOD proteins would most likely have impaired ability to:

Accepted Answer

Trigger inflammation and apoptosis in response to intracellular pathogens

Question 19

Which of the following best describes the effect of vasodilation during inflammation?

Accepted Answer

It increases blood flow, resulting in redness and heat at the site of injury.

Question 20

Which of the following is a plausible outcome if the lacrimal apparatus is nonfunctional?

Accepted Answer

Increased risk of eye infections due to reduced washing action and lysozyme activity

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

Study Guide - Practice Questions