Question 1

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

Accepted Answer

They are pattern recognition receptors that bind to specific molecules on pathogens and trigger immune responses.

Question 2

A patient receives a mismatched blood transfusion and experiences rapid destruction of the transfused cells. Which type of hypersensitivity reaction is this, and which immunoglobulin is primarily involved?

Accepted Answer

Cytotoxic hypersensitivity; IgM

Question 3

Which of the following is NOT a function of inflammation?

Accepted Answer

Directly produces antibodies to neutralize pathogens

Question 4

A virus-infected cell releases interferons. What is the primary effect of these interferons on neighboring cells?

Accepted Answer

They stimulate neighboring cells to produce proteins that block viral replication.

Question 5

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

Accepted Answer

They introduce antigens that stimulate the formation of memory B cells, leading to a faster and stronger secondary immune response.

Question 6

Which of the following is a correct sequence of events during phagocytosis?

Accepted Answer

Phagocyte adheres to pathogen → Phagosome forms → Lysosome fuses with phagosome → Pathogen is digested

Question 7

A patient with a genetic defect in complement protein C3 is likely to experience which of the following problems?

Accepted Answer

Increased susceptibility to bacterial infections due to impaired opsonization and cell lysis

Question 8

Which of the following statements about Major Histocompatibility Complex (MHC) proteins is TRUE?

Accepted Answer

MHC proteins display peptide fragments for recognition by T cells.

Question 9

Which of the following best describes the difference between active and passive humoral immunity?

Accepted Answer

Active immunity involves the production of memory cells, while passive immunity does not.

Question 10

A patient is diagnosed with an autoimmune disease. Which of the following best explains the underlying mechanism?

Accepted Answer

The immune system fails to distinguish self from non-self and attacks the body's own tissues.

Question 11

Which of the following is a function of helper T cells (CD4+)?

Accepted Answer

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

Question 12

Which of the following best describes the process of opsonization?

Accepted Answer

Pathogens are coated with molecules such as antibodies or complement proteins to enhance phagocytosis.

Question 13

Which immunoglobulin class is the first to be released during a primary immune response and is a potent agglutinating agent?

Accepted Answer

IgM

Question 14

A patient is exposed to poison ivy and develops a skin rash 2 days later. Which type of hypersensitivity is this, and which immune cells are primarily responsible?

Accepted Answer

Delayed hypersensitivity; T cells

Question 15

Which of the following best explains why HIV infection leads to immunodeficiency?

Accepted Answer

HIV destroys helper T cells, impairing both humoral and cellular immunity.

Question 16

Which of the following is a correct description of the 'PLAN' mechanisms of antibody action?

Accepted Answer

Precipitation, Lysis (via complement), Agglutination, Neutralization

Question 17

Which of the following best describes the process of positive selection during T cell maturation in the thymus?

Accepted Answer

T cells that recognize self-MHC proteins survive; those that do not are eliminated.

Question 18

A patient receives an injection of gamma globulin after exposure to hepatitis A. Which type of immunity is this, and what is a key characteristic?

Accepted Answer

Artificially acquired passive immunity; no memory cells are produced

Question 19

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

Accepted Answer

A high percentage of a population is vaccinated against measles, reducing the spread of the disease and protecting unvaccinated individuals.

Chapter 21: The Immune System – Innate and Adaptive Body Defenses

Guida di studio - Domande di pratica

Study guide - Flashcard