Question 1

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

Accepted Answer

Innate immunity is nonspecific and provides immediate defense, while adaptive immunity is specific and develops memory after exposure.

Question 2

A patient receives a flu vaccine and later develops antibodies against the flu virus. This is an example of which type of immunity?

Accepted Answer

Artificially acquired active immunity

Question 3

Which immune cell is primarily responsible for directly attacking and killing virus-infected cells?

Accepted Answer

Cytotoxic T cells

Question 4

Which antibody class is most abundant in plasma and can cross the placental barrier to provide passive immunity to the fetus?

Accepted Answer

IgG

Question 5

A person with a genetic defect that prevents the production of complement proteins would most likely experience which of the following?

Accepted Answer

Decreased inflammation and impaired cell lysis

Question 6

Which of the following is a function of interferons during a viral infection?

Accepted Answer

Induce neighboring cells to produce antiviral proteins

Question 7

A patient with an autoimmune disease is producing antibodies that attack their own tissues. Which process failed during T cell maturation?

Accepted Answer

Negative selection for self-antigen tolerance

Question 8

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

Accepted Answer

It causes the liver and spleen to sequester iron and zinc, and increases metabolic rate to speed up repair.

Question 9

Which of the following is the correct sequence of events in the humoral immune response after first exposure to an antigen?

Accepted Answer

Antigen challenge → clonal selection → plasma cell formation → antibody secretion

Question 10

Which of the following best describes the role of antigen-presenting cells (APCs) in adaptive immunity?

Accepted Answer

They engulf antigens and present fragments on MHC proteins to T cells.

Question 11

A patient receives an injection of gamma globulin after exposure to hepatitis. Which type of immunity is this?

Accepted Answer

Artificially acquired passive immunity

Question 12

Which of the following is a cardinal sign of acute inflammation?

Accepted Answer

Redness

Question 13

Which of the following best describes the process of opsonization?

Accepted Answer

Antibodies or complement proteins coat pathogens to enhance phagocytosis.

Question 14

Which cell type is responsible for suppressing the immune response and preventing autoimmune reactions?

Accepted Answer

Regulatory T cells

Question 15

Which of the following is a real-life example of agglutination caused by antibodies?

Accepted Answer

Clumping of mismatched blood cells during a transfusion reaction

Question 16

Which of the following best explains why organ transplant recipients must take immunosuppressive drugs?

Accepted Answer

To prevent the immune system from attacking the transplanted tissue as foreign

Question 17

Which of the following is the main antibody defense mechanism against cellular antigens, such as bacteria?

Accepted Answer

Complement fixation and activation

Question 18

A patient with AIDS is most likely to have a deficiency in which immune cell type?

Accepted Answer

Helper T cells

Question 19

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

Accepted Answer

B cells with receptors specific to an antigen proliferate and form clones after antigen binding.

Question 20

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

Accepted Answer

It produces higher levels of antibodies more rapidly.

The Immune System: Innate and Adaptive Body Defenses

Study Guide - Practice Questions