Question 1

Which of the following best describes the role of keratin in the skin as part of the immune system's first line of defense?

Accepted Answer

Keratin forms a physical barrier that is resistant to weak acids, bases, bacterial enzymes, and toxins.

Question 2

A patient receives an injection of antivenom after a snake bite. Which type of immunity is this an example of?

Accepted Answer

Passive artificial immunity

Question 3

During inflammation, neutrophils are attracted to the site of injury by chemicals released from damaged tissues. This process is known as:

Accepted Answer

Chemotaxis

Question 4

Which of the following is NOT a symptom of inflammation?

Accepted Answer

Increased blood pressure

Question 5

Natural Killer (NK) cells eliminate infected or abnormal cells by releasing which two types of cytolytic chemicals?

Accepted Answer

Perforins and granzymes

Question 6

Which equation best represents the relationship between herd immunity and the basic reproduction number ($$R_0) of a $$disease?

Accepted Answer

The herd immunity threshold is given by $$H = 1 - \frac{1}{R_0$}$$

Question 7

Which of the following best describes the function of interferons released by viral-infected cells?

Accepted Answer

Interferons block viral replication and activate macrophages and NK cells.

Question 8

A child receives a vaccine for measles. Which type of immunity is being acquired?

Accepted Answer

Active artificial immunity

Question 9

Which of the following is TRUE regarding the difference between B and T lymphocytes?

Accepted Answer

B lymphocytes are responsible for humoral immunity, while T lymphocytes are responsible for cellular immunity.

Question 10

Which antibody is primarily responsible for crossing the placenta and providing passive immunity to the fetus?

Accepted Answer

IgG

Question 11

A patient develops a fever after a bacterial infection. Which chemical is most likely responsible for this response?

Accepted Answer

Pyrogens

Question 12

Which of the following best describes the process of phagocytosis?

Accepted Answer

Phagocytes engulf pathogens, fuse with lysosomes, and destroy them with acid hydrolase enzymes.

Question 13

Which step in the inflammatory response involves neutrophils squeezing through capillary walls to reach the site of injury?

Accepted Answer

Diapedesis

Question 14

Which of the following is a hallmark and most important mechanism of innate immunity?

Accepted Answer

Inflammation

Question 15

Which of the following is TRUE about memory cells in adaptive immunity?

Accepted Answer

Memory cells reduce response time upon second exposure to the same pathogen.

Question 16

Which of the following best describes the function of complement proteins in innate immunity?

Accepted Answer

Complement proteins increase inflammatory response, promote phagocytosis, and help lyse pathogens.

Question 17

A newborn receives antibodies from breast milk. Which type of immunity is this?

Accepted Answer

Passive natural immunity

Question 18

Which of the following is a real-world example of cell-mediated immunity?

Accepted Answer

A cytotoxic T cell attacks a viral-infected cell and lyses it.

Question 19

Which of the following best explains why the secondary immune response is faster and stronger than the primary response?

Accepted Answer

Memory cells generated during the primary response allow for rapid antibody production upon re-exposure.

Question 20

Which of the following is TRUE regarding the maturation of lymphocytes?

Accepted Answer

B cells mature in the bone marrow, while T cells mature in the thymus.

Study Guide: The Immune System – Innate and Adaptive Defenses

Study Guide - Practice Questions