Question 1

Which of the following best describes the main function of lymph nodes in the lymphatic system?

Accepted Answer

They filter and cleanse lymph by removing microorganisms, debris, and abnormal cells.

Question 2

A patient receives an injection of antibodies after being exposed to rabies. This is an example of which type of immunity?

Accepted Answer

Passive, artificially acquired immunity

Question 3

Which of the following is NOT a function of the spleen?

Accepted Answer

Production of insulin

Question 4

Which of the following best explains why antibiotics are ineffective against viral infections?

Accepted Answer

Viruses lack a cell wall and metabolic processes targeted by antibiotics.

Question 5

A person develops a fever after a bacterial infection. What is the primary benefit of this fever?

Accepted Answer

It makes the body less hospitable to pathogens and enhances immune defenses.

Question 6

Which of the following is a correct sequence of events in the inflammatory response?

Accepted Answer

Release of histamine → increased blood flow → attraction of phagocytes → tissue repair

Question 7

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

Accepted Answer

They are secreted by virus-infected cells to warn neighboring cells and induce antiviral proteins.

Question 8

Which of the following is a characteristic of the adaptive (specific) immune response?

Accepted Answer

It has memory and responds more rapidly upon subsequent exposures to the same antigen.

Question 9

Which class of antibody is most prevalent in the blood and can cross the placenta to protect the fetus?

Accepted Answer

IgG

Question 10

A person is exposed to a pathogen for the first time and develops symptoms after several days. Which immune response is responsible for this delay?

Accepted Answer

Primary immune response

Question 11

Which of the following best describes the function of cytotoxic T cells?

Accepted Answer

They directly attack and destroy infected or abnormal cells.

Question 12

Which of the following is a real-world example of competitive exclusion by the human microbiota?

Accepted Answer

Beneficial gut bacteria outcompete harmful bacteria for nutrients, reducing the risk of infection.

Question 13

Which of the following is a correct statement about the complement system?

Accepted Answer

It consists of proteins that, when activated, can lyse invading microorganisms.

Question 14

A child receives a vaccine containing an inactivated virus. What type of immunity does this confer?

Accepted Answer

Active, artificially acquired immunity

Question 15

Which of the following best explains why the thymus gland is most active during childhood?

Accepted Answer

It is the primary site for T cell maturation, which is crucial for developing a functional immune system.

Question 16

Which of the following is a function of helper T cells?

Accepted Answer

They secrete cytokines to stimulate other immune cells.

Question 17

Which of the following best describes the role of MHC proteins in the immune system?

Accepted Answer

They act as self-antigens, enabling the immune system to distinguish self from nonself.

Question 18

Which of the following is a plausible consequence of broad-spectrum antibiotic use?

Accepted Answer

Disruption of normal microbiota, leading to increased risk of opportunistic infections.

Question 19

Which of the following is a correct statement about phagocytes?

Accepted Answer

They engulf and digest foreign cells through phagocytosis.

Question 20

A patient with a weakened immune system develops an infection from a normally harmless bacterium. This is an example of:

Accepted Answer

An opportunistic infection

The Immune System and Mechanisms of Defense

Study Guide - Practice Questions