Question 1

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

Accepted Answer

Adaptive immunity produces immunological memory, allowing for a rapid and effective response upon subsequent exposures.

Question 2

Which cell type is primarily responsible for antibody-mediated (humoral) immunity?

Accepted Answer

B cells

Question 3

What is the main function of memory cells in adaptive immunity?

Accepted Answer

To remain in lymphatic tissues and rapidly respond to subsequent exposures to the same antigen

Question 4

Which of the following best describes the process of clonal expansion in adaptive immunity?

Accepted Answer

The proliferation of lymphocytes that recognize a specific antigen, resulting in effector and memory cells

Question 5

A patient receives a vaccine and later is exposed to the same pathogen. Which adaptive immune response is responsible for the rapid elimination of the pathogen?

Accepted Answer

Secondary response

Question 6

Which of the following statements about antigen presentation is correct?

Accepted Answer

MHC I proteins present intracellular antigens to T cytotoxic cells.

Question 7

Which of the following is a function of antibodies produced by plasma cells?

Accepted Answer

Activating complement, neutralizing toxins, and opsonizing pathogens

Question 8

Which antibody isotype is most abundant in serum and crosses the placenta to provide passive immunity to the fetus?

Accepted Answer

IgG

Question 9

A person receives antibodies from another individual through injection. What type of immunity is this?

Accepted Answer

Artificially acquired passive immunity

Question 10

Which of the following best explains why haptens do not trigger an immune response unless linked to a larger molecule?

Accepted Answer

Haptens are too small and lack sufficient molecular complexity to be recognized by lymphocyte receptors.

Question 11

Which of the following is a correct statement about T cell tolerance?

Accepted Answer

Immature T cells that do not tolerate self MHC proteins undergo apoptosis in the thymus.

Question 12

Which subclass of T helper cells is primarily responsible for activating cytotoxic T cells and macrophages to fight intracellular pathogens?

Accepted Answer

T helper 1 (Th1) cells

Question 13

Which of the following is a consequence of superantigen activation of T helper cells?

Accepted Answer

Direct crosslinking of MHC II and T cell receptors, leading to massive cytokine release

Question 14

Which equation best represents the relationship between antibody titer and time during a secondary immune response?

Accepted Answer

$$Antibody\ Titer = A \cdot e$$^{kt}$$, where A$ is initial concentration and k$ is rate constant$

Question 15

Which of the following best describes the role of MHC II proteins?

Accepted Answer

Present extracellular antigens to helper T cells

Question 16

A patient is unable to produce functional T helper cells. Which of the following immune responses would be most affected?

Accepted Answer

Activation of B cells and production of high-affinity antibodies

Question 17

Which of the following is true regarding isotype switching in plasma cells?

Accepted Answer

Isotype switching allows a plasma cell to produce different classes of antibodies while maintaining specificity for the same epitope.

Question 18

Which of the following is a correct sequence of the four general stages of the adaptive immune response?

Accepted Answer

Antigen presentation, lymphocyte activation, proliferation and differentiation, antigen elimination and memory

Question 19

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

Accepted Answer

Vaccines induce immunological memory, allowing for a rapid and effective secondary response upon exposure to the pathogen.

Adaptive Immunity: The Third Line of Defense in Microbiology

Study Guide - Practice Questions

Study Guide - Flashcards