Question 1

Which of the following best describes the main difference between the innate and adaptive immune systems?

Accepted Answer

The innate immune system responds rapidly and nonspecifically to pathogens, while the adaptive immune system responds more slowly but with high specificity to particular antigens.

Question 2

Which cell type is primarily responsible for releasing histamine during the inflammatory response, and what is the effect of histamine?

Accepted Answer

Mast cells; histamine dilates blood vessels and increases their permeability.

Question 3

A patient receives a kidney transplant from a non-relative. Which immune system component is most likely to cause rejection of the transplanted organ?

Accepted Answer

Adaptive immune cells recognizing foreign antigens presented by the organ's MHC proteins.

Question 4

Which of the following best explains why memory cells provide a faster and stronger response upon second exposure to the same antigen?

Accepted Answer

Memory cells have undergone somatic hypermutation, resulting in receptors with higher affinity for the antigen's epitope.

Question 5

Which of the following is a function of antibodies in the humoral immune response?

Accepted Answer

They coat pathogens, marking them for phagocytosis by macrophages (opsonization).

Question 6

Which of the following best describes the role of Toll-like receptors (TLRs) in the innate immune system?

Accepted Answer

TLRs are membrane receptors that recognize pathogen-associated molecular patterns and activate innate immune responses.

Question 7

A virus mutates rapidly, changing its surface epitopes. What is the most likely consequence for the adaptive immune response?

Accepted Answer

Memory cells generated from a previous infection may not recognize the new epitopes, reducing the effectiveness of the secondary immune response.

Question 8

Which immunoglobulin class is the first to be produced during a primary immune response and is most effective at clumping viruses and bacteria?

Accepted Answer

IgM

Question 9

What is the main function of cytotoxic (CD8+) T cells in the cell-mediated immune response?

Accepted Answer

They recognize and kill virus-infected host cells displaying antigen with MHC class I proteins.

Question 10

Which of the following best describes the process of antigen presentation by dendritic cells?

Accepted Answer

Dendritic cells ingest antigens, process them, and display antigen fragments bound to MHC proteins on their surface for recognition by T cells.

Question 11

Which of the following is a key feature of the clonal selection theory?

Accepted Answer

Activated lymphocytes divide and produce identical clones, some of which become memory cells.

Question 12

Which of the following best explains why vaccines are effective in preventing infectious diseases?

Accepted Answer

Vaccines introduce antigens that stimulate a primary immune response, generating memory cells for rapid secondary response upon real infection.

Question 13

A person with a genetic defect preventing the production of MHC class I proteins would have the most difficulty with which immune function?

Accepted Answer

Presenting viral antigens to cytotoxic T cells for destruction of infected cells.

Question 14

Which of the following is a real-world example of the importance of self-nonself recognition by the immune system?

Accepted Answer

The ability of the immune system to distinguish between the body's own cells and transplanted organ cells, leading to possible organ rejection.

Question 15

Which of the following best describes the role of helper (CD4+) T cells in the adaptive immune response?

Accepted Answer

They interact with antigen-presenting cells via MHC class II proteins and secrete cytokines to activate B cells and cytotoxic T cells.

Question 16

Which of the following is a characteristic of the secondary immune response compared to the primary immune response?

Accepted Answer

It is faster and produces a larger quantity of antibodies due to the presence of memory cells.

Question 17

Which of the following best explains why allergies can lead to anaphylactic shock?

Accepted Answer

Allergens cause mast cells to release large amounts of histamine and other chemicals, leading to widespread blood vessel dilation and increased permeability.

Question 18

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

Accepted Answer

Pathogens enter wound → platelets release clotting proteins → mast cells secrete histamine → neutrophils and macrophages remove pathogens.

Question 19

Which of the following best describes the function of mucosal-associated lymphoid tissue (MALT)?

Accepted Answer

MALT guards points of entry in the digestive and respiratory tracts by housing large numbers of lymphocytes.

The Immune System: Innate and Adaptive Immunity

Study Guide - Practice Questions

Study Guide - Flashcards