Question 1

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

Accepted Answer

They recognize specific-shaped molecules on pathogens and trigger immune responses.

Question 2

A patient receives a mismatched blood transfusion and develops a severe reaction. Which type of hypersensitivity is most likely responsible for this reaction?

Accepted Answer

Cytotoxic (Type II) hypersensitivity

Question 3

Which antibody class is most effective at agglutinating pathogens and is the first antibody released during a primary immune response?

Accepted Answer

IgM

Question 4

A child is born with a genetic defect resulting in a marked deficit of both B and T cells. Which condition does this describe, and what is the most effective treatment?

Accepted Answer

SCID; hematopoietic stem cell transplant

Question 5

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

Accepted Answer

Activate B cells and cytotoxic T cells by releasing cytokines

Question 6

Which process best explains why a person who recovers from chickenpox is usually immune to future infections with the same virus?

Accepted Answer

Production of memory B and T cells during the primary immune response

Question 7

Which of the following best describes the mechanism of action for cytotoxic T cells (CD8+)?

Accepted Answer

They release perforins and granzymes to induce apoptosis in target cells.

Question 8

A patient is exposed to hepatitis A and receives an injection of gamma globulin (antibodies) for immediate protection. Which type of immunity is this?

Accepted Answer

Artificially acquired passive immunity

Question 9

Which of the following is a key difference between innate and adaptive immunity?

Accepted Answer

Adaptive immunity has memory and is antigen-specific, while innate immunity is nonspecific and present at birth.

Question 10

Which of the following best explains why fever can be beneficial during an infection?

Accepted Answer

It increases the metabolic rate, enhances immune cell migration, and suppresses bacterial growth by limiting iron availability.

Question 11

Which of the following is TRUE regarding antigen-presenting cells (APCs)?

Accepted Answer

They include dendritic cells, macrophages, and B lymphocytes.

Question 12

Which of the following best describes the process of opsonization?

Accepted Answer

Antibodies or complement proteins coat pathogens, enhancing their uptake by phagocytes.

Question 13

A patient develops an autoimmune disease after a streptococcal infection. Which mechanism best explains this phenomenon?

Accepted Answer

Antibodies produced against the bacteria cross-react with self-antigens due to molecular mimicry.

Question 14

Which of the following is a characteristic of IgG antibodies?

Accepted Answer

They are the main antibody of secondary and late primary responses and can cross the placenta.

Question 15

Which of the following best describes the role of the complement system in immunity?

Accepted Answer

It is a group of plasma proteins that, when activated, enhance inflammation, promote phagocytosis, and directly lyse pathogens.

Question 16

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

Accepted Answer

They suppress immune responses to prevent autoimmunity.

Question 17

Which of the following best explains why plastics are used for artificial implants in the body?

Accepted Answer

Plastics are large, simple molecules with many identical repeating units, making them poorly immunogenic.

Question 18

Which of the following is a correct statement about the difference between MHC class I and class II proteins?

Accepted Answer

MHC class I proteins are found on all nucleated cells and present endogenous antigens to CD8+ T cells.

Question 19

A person 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 involved?

Accepted Answer

Delayed hypersensitivity; T cells and macrophages

Chapter 21

Guida di studio - Domande di pratica

Study guide - Flashcard