Question 1

Which of the following best describes the main structural difference between prokaryotic and eukaryotic cells?

Accepted Answer

Prokaryotic cells lack a nucleus and membrane-bound organelles, while eukaryotic cells have both.

Question 2

A patient is prescribed antibiotics for a viral infection. Why is this treatment likely to be ineffective?

Accepted Answer

Viruses lack the cell wall structure that antibiotics like penicillin target in bacteria.

Question 3

Which immune cell is primarily responsible for phagocytosing pathogens and presenting antigens to T-cells?

Accepted Answer

Macrophage

Question 4

Which of the following is NOT a function of cytokines in the immune response?

Accepted Answer

Directly phagocytosing pathogens

Question 5

A person develops oral thrush after taking antibiotics. What is the most likely explanation for this occurrence?

Accepted Answer

The antibiotics killed normal flora, allowing fungi to overgrow.

Question 6

Which of the following best describes the process of opsonization by complement proteins?

Accepted Answer

Complement proteins bind to pathogens, making them easier for phagocytes to recognize and engulf.

Question 7

During inflammation, which step involves leukocytes squeezing through the endothelium to reach the site of infection?

Accepted Answer

Diapedesis

Question 8

Which immune cell releases histamine and heparin to promote inflammation and prevent blood coagulation?

Accepted Answer

Basophil

Question 9

Natural killer (NK) cells destroy infected or abnormal cells by releasing which two substances?

Accepted Answer

Perforin and granzymes

Question 10

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

Accepted Answer

Fever increases metabolic rate and tissue repair, and can reduce infectious agent activity.

Question 11

Which class of antibody is most abundant in blood and can cross the placenta to provide passive immunity to the fetus?

Accepted Answer

IgG

Question 12

A patient is exposed to a pathogen for the second time. Which immune cells are responsible for the rapid and robust antibody response?

Accepted Answer

Memory B-cells

Question 13

Which of the following best describes the role of MHC class I molecules?

Accepted Answer

They are found on all nucleated cells and present antigens to cytotoxic T-cells.

Question 14

Which of the following equations correctly represents the relationship between CD4, CD8, and MHC classes for T-cell activation?

Accepted Answer

$$CD4 	imes MHC\ II = 8$$

Question 15

Which of the following is a function of interferons during a viral infection?

Accepted Answer

They stimulate neighboring cells to produce antiviral proteins and recruit NK cells.

Question 16

A person with a deficiency in helper T-cells (CD4+) would likely have problems with which of the following?

Accepted Answer

Producing antibodies and activating cytotoxic T-cells

Question 17

Which of the following best describes the process of clonal selection?

Accepted Answer

A single lymphocyte divides rapidly after activation by a specific antigen, producing many identical cells.

Question 18

Which of the following is an example of passive immunity?

Accepted Answer

Receiving antibodies from a mother’s breast milk

Question 19

Which immune cell is primarily responsible for releasing cytotoxic chemicals to destroy parasitic worms?

Accepted Answer

Eosinophil

Question 20

A patient experiences anaphylaxis after exposure to an allergen. Which immune cell is most responsible for this reaction, and what is the first-line treatment?

Accepted Answer

Basophil; epinephrine injection

Chapter 22: The Immune System – Structure, Function, and Defense Mechanisms

Study Guide - Practice Questions

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