Question 1

Which of the following best describes the main function of the immune system?

Accepted Answer

To provide resistance to disease by stopping attacks from pathogens such as bacteria, fungi, and viruses.

Question 2

Which of the following is NOT a component of the innate (nonspecific) defense system?

Accepted Answer

B lymphocytes

Question 3

A patient has a genetic defect that prevents the production of lysozyme in their saliva. Which first line of defense is most directly compromised?

Accepted Answer

Enzymatic destruction of microorganisms at mucosal surfaces

Question 4

Which of the following best explains the role of pattern recognition receptors in innate immunity?

Accepted Answer

They recognize pathogen-associated molecular patterns (PAMPs) on microbes, triggering an immune response.

Question 5

During the inflammatory response, which of the following events occurs first?

Accepted Answer

Release of inflammatory chemicals

Question 6

A child receives a vaccine containing dead or attenuated pathogens. Which type of immunity is being developed?

Accepted Answer

Artificially acquired active humoral immunity

Question 7

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

Accepted Answer

Adherence to pathogen → Formation of phagosome → Fusion with lysosome → Digestion → Exocytosis of residual material

Question 8

Which of the following best describes the function of interferons?

Accepted Answer

They are proteins released by virus-infected cells that protect uninfected tissue from viruses and mobilize the immune system.

Question 9

A patient with a fever is experiencing which of the following benefits?

Accepted Answer

Increased metabolic rate, which accelerates tissue repair

Question 10

Which of the following statements about antigens is TRUE?

Accepted Answer

Antigens are substances that can mobilize the adaptive defenses and provoke an immune response.

Question 11

Which of the following is a key difference between the primary and secondary humoral immune responses?

Accepted Answer

The secondary response is faster and produces higher levels of antibodies than the primary response.

Question 12

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

Accepted Answer

They activate B cells, other T cells, and macrophages.

Question 13

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

Accepted Answer

The immune system loses the ability to distinguish self from foreign and attacks the body's own tissues.

Question 14

Which of the following is a characteristic of the adaptive immune system?

Accepted Answer

It has memory and can mount a stronger attack upon subsequent exposures to the same antigen.

Question 15

Which of the following best describes the function of MHC proteins in the immune response?

Accepted Answer

They present antigen fragments on the surface of cells for recognition by T cells.

Question 16

A patient is stung by a bee and develops anaphylactic shock within minutes. Which type of hypersensitivity is this?

Accepted Answer

Type I: Immediate hypersensitivity

Question 17

Which of the following mechanisms is used by antibodies to inactivate antigens?

Accepted Answer

Neutralization, agglutination, precipitation, and complement fixation

Question 18

A patient with severe combined immunodeficiency (SCID) syndrome is unable to mount an effective immune response. Which cells are most likely deficient?

Accepted Answer

Both B and T lymphocytes

Question 19

Which of the following best describes the process of clonal selection in B lymphocytes?

Accepted Answer

A B cell with a receptor specific for an antigen is activated, proliferates, and differentiates into plasma cells and memory cells.

Question 20

Which of the following is a benefit of moderate fever during infection?

Accepted Answer

It causes the liver and spleen to sequester iron and zinc, limiting microbial growth.

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

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