Question 1

Which of the following best describes the difference between innate and adaptive immunity?

Accepted Answer

Innate immunity provides a rapid, non-specific response to pathogens, while adaptive immunity provides a slower, highly specific response using a vast array of receptors.

Question 2

A patient receives a splinter in their finger. Which sequence of events correctly describes the local inflammatory response?

Accepted Answer

Mast cells release histamines, capillaries dilate, neutrophils are recruited, and phagocytosis of pathogens occurs.

Question 3

Which of the following is an example of a barrier defense in innate immunity?

Accepted Answer

Skin preventing entry of pathogens

Question 4

During phagocytosis, which step immediately follows the engulfment of a pathogen by a phagocytic cell?

Accepted Answer

Formation of a vacuole containing the pathogen

Question 5

A plant infected by a pathogen exhibits a hypersensitive response. What is the primary function of this response?

Accepted Answer

To cause rapid cell death at the infection site, limiting pathogen spread

Question 6

Which of the following best explains why adaptive immunity is slower to respond than innate immunity?

Accepted Answer

Adaptive immunity requires the production and selection of specific lymphocytes that recognize unique antigens.

Question 7

Which of the following is a correct example of self-tolerance in the immune system?

Accepted Answer

Elimination of B cells that react strongly to self-antigens during development

Question 8

A person is exposed to antigen A and later to antigen B. According to the graph of immunological memory, what happens to the antibody concentration for antigen A after the second exposure?

Accepted Answer

It increases rapidly and to a higher level than after the first exposure.

Question 9

Which of the following best describes the role of helper T cells in the immune response?

Accepted Answer

They activate B cells and cytotoxic T cells by releasing cytokines.

Question 10

A vaccine works by stimulating which aspect of the immune system?

Accepted Answer

The production of memory cells specific to the vaccine antigen

Question 11

Which of the following is a correct sequence of events in the clonal selection of B cells?

Accepted Answer

Antigen binds to B cell receptor → B cell divides → Plasma and memory cells are produced

Question 12

Which of the following is a real-world example of innate immunity in humans?

Accepted Answer

Stomach acid killing harmful microbes in ingested food

Question 13

Which immune cell is primarily responsible for engulfing and destroying pathogens during the innate immune response?

Accepted Answer

Phagocytic cell (e.g., macrophage or neutrophil)

Question 14

In the context of plant immunity, what is the function of methylsalicylic acid?

Accepted Answer

It is exported to uninfected parts of the plant to trigger systemic acquired resistance.

Question 15

Which of the following best explains why the adaptive immune system can respond more rapidly and effectively to a second exposure to the same pathogen?

Accepted Answer

Memory cells specific to the pathogen are produced during the first exposure, allowing a faster and stronger response upon re-exposure.

Question 16

Which of the following is a correct example of a humoral immune response?

Accepted Answer

Antibodies binding to and neutralizing a virus in the bloodstream

Question 17

A mutation causes a person’s phagocytic cells to lack functional lysosomes. Which step in phagocytosis would be directly impaired?

Accepted Answer

Fusion of the vacuole with the lysosome and subsequent destruction of the pathogen

Question 18

Which of the following is a real-world example of a plant’s physical defense against pathogens?

Accepted Answer

Formation of thorns or spines on leaves and stems

Question 19

Which of the following best describes the function of cytotoxic T cells in the adaptive immune response?

Accepted Answer

They recognize and kill infected host cells by releasing perforin and granzymes.

Immune and Defense Systems: Concept Challenge Study Guide

Study Guide - Practice Questions

Study Guide - Flashcards