$$\text{Likelihood of infection} \propto \text{Leukocyte concentration}$$

Question 1

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

Accepted Answer

Neutrophils phagocytize pathogens and can kill microbes using chemicals and NETs.

Question 2

Which leukocyte is most likely to be elevated in a patient with a parasitic worm infection?

Accepted Answer

Eosinophil

Question 3

What is the primary function of platelets in the blood?

Accepted Answer

Clotting and inflammation

Question 4

Which of the following is NOT a target for Toll-like receptors (TLRs)?

Accepted Answer

Eukaryotic flagellar protein

Question 5

During phagocytosis, which stage involves the movement of phagocytes toward the site of infection?

Accepted Answer

Chemotaxis

Question 6

Which of the following best describes the action of alpha and beta interferons?

Accepted Answer

They slow the spread of viral infections by activating antiviral proteins in neighboring cells.

Question 7

A patient with a viral infection is likely to show an increase in which type of leukocyte?

Accepted Answer

Lymphocytes

Question 8

Which of the following is a correct sequence for the stages of phagocytosis?

Accepted Answer

Chemotaxis → Adhesion → Ingestion → Maturation → Killing → Elimination

Question 9

Which granulocyte is responsible for releasing inflammatory chemicals but does NOT phagocytize pathogens?

Accepted Answer

Basophil

Question 10

Which of the following statements about NOD proteins is TRUE?

Accepted Answer

NOD proteins are cytosolic proteins that bind PAMPs and trigger inflammation and apoptosis.

Question 11

Which of the following equations best represents the relationship between the concentration of leukocytes and the likelihood of bacterial infection?

Accepted Answer

$$	ext{Likelihood of infection} \propto 	ext{Leukocyte concentration}$$

Question 12

Which of the following is a function of monocytes in the second line of defense?

Accepted Answer

Devour foreign objects through phagocytosis

Question 13

Which Toll-like receptor (TLR) is responsible for recognizing double-stranded RNA found only in viruses?

Accepted Answer

TLR3

Question 14

Which of the following best explains why some microbes produce proteins that bind iron?

Accepted Answer

To evade host immune defenses by competing for iron needed for metabolism

Question 15

Which of the following is TRUE regarding the function of eosinophils?

Accepted Answer

Eosinophils attack helminths and can kill pathogens without phagocytosis.

Question 16

Which of the following best describes the difference between plasma and serum?

Accepted Answer

Plasma contains clotting factors, while serum does not.

Question 17

Which of the following is a characteristic of natural killer (NK) lymphocytes?

Accepted Answer

They kill infected or abnormal cells as part of innate immunity.

Question 18

Which of the following best describes the action of gamma interferon?

Accepted Answer

It is produced late in infection by T lymphocytes and NK cells.

Question 19

Which of the following is a plausible consequence of a deficiency in complement proteins in plasma?

Accepted Answer

Reduced ability to opsonize and lyse pathogens

Question 20

Which of the following best describes the process of diapedesis?

Accepted Answer

The movement of leukocytes out of the blood vessels into tissues to fight infection

Innate Immunity: The Second Line of Defense

Study Guide - Practice Questions