Question 1

Which of the following best describes the primary function of neutrophils in the immune response?

Accepted Answer

They are phagocytes that ingest and destroy bacteria, especially during acute infections.

Question 2

A patient presents with a parasitic worm infection. Which leukocyte is most likely to increase in number and what is its mechanism of action?

Accepted Answer

Eosinophils; surround the parasite and release digestive enzymes.

Question 3

Which of the following is a key difference between innate and adaptive immunity?

Accepted Answer

Adaptive immunity involves specific recognition of antigens and clonal expansion of lymphocytes.

Question 4

During inflammation, which process describes the movement of leukocytes out of the capillaries and into the tissues?

Accepted Answer

Diapedesis

Question 5

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

Accepted Answer

It causes the liver and spleen to sequester iron and zinc, limiting bacterial growth.

Question 6

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

Accepted Answer

Plasma cells derived from B lymphocytes

Question 7

A patient undergoing chemotherapy develops leukopenia. What is the most likely consequence?

Accepted Answer

Increased risk of infection due to decreased white blood cell count.

Question 8

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

Accepted Answer

They are secreted by virus-infected cells and help protect neighboring cells by blocking viral replication.

Question 9

Which of the following is a function of the complement system in immunity?

Accepted Answer

Amplifying the inflammatory response and forming membrane attack complexes to lyse pathogens.

Question 10

A blood smear shows a high number of large cells with U-shaped nuclei. Which cell type is this, and what is its primary function?

Accepted Answer

Monocyte; differentiates into macrophages and phagocytizes pathogens during chronic infections.

Question 11

Which of the following best describes the process of opsonization?

Accepted Answer

The coating of pathogens by complement proteins or antibodies to enhance phagocytosis.

Question 12

Which of the following is NOT a first line of defense in the innate immune system?

Accepted Answer

T lymphocytes

Question 13

Which of the following best explains why high fever is dangerous?

Accepted Answer

It can denature enzymes and proteins, disrupting normal cellular functions.

Question 14

Which of the following is a characteristic of basophils?

Accepted Answer

They contain large cytoplasmic granules with histamine and have an S- or U-shaped nucleus.

Question 15

Which of the following best describes the role of natural killer (NK) cells?

Accepted Answer

They attack virus-infected or cancer cells lacking MHC I molecules and can be triggered by PAMPs or DAMPs.

Question 16

Which of the following is the correct sequence of events during leukocyte migration to an inflamed site?

Accepted Answer

Leukocytosis → Margination → Diapedesis → Chemotaxis

Question 17

Which of the following best describes the function of defensins?

Accepted Answer

They are broad-spectrum antimicrobial peptides secreted by mucous membranes and skin.

Question 18

A patient is diagnosed with leukemia. Which of the following best describes the pathophysiology of this disease?

Accepted Answer

Cancerous proliferation of unspecialized, non-functional white blood cells leading to anemia and increased infection risk.

Question 19

Which of the following best describes the role of PAMPs and DAMPs in the immune response?

Accepted Answer

They are molecular patterns that trigger the innate immune system without the need for specific recognition.

Question 20

Which of the following best describes the process of leukopoiesis?

Accepted Answer

It is hormonally regulated production of leukocytes from hemocytoblasts, involving interleukins and colony-stimulating factors.

Leukocytes and the Immune System: Structure, Function, and Defense Mechanisms

Study Guide - Practice Questions