Immune System Overview

Question 1

Central (primary) lymphoid organs
a. are efficient in exposing T cells to foreign antigen.
b. are the primary site of antibody synthesis and release.
c. filter blood and trap blood-borne antigens.
d. provide the microenvironment for maturation of T and B cells.
e. line the mucosal surfaces of the body for efficient antigen contact.

Answer 1

d. provide the microenvironment for maturation of T and B cells.

Question 2

Hematopoietic stem cells are pluripotent, which means that they are
a. antigen-specific cells.
b. capable of developing into any blood cells.
c. committed to produce cells of a single lineage.
d. not self-renewing.
e. T and B lymphocytes of many different antigen specificities.

Answer 2

b. capable of developing into any blood cells.

Question 3

Lymphocytes continually recirculate through peripheral lymphoid tissue in order to
a. be killed before they cause autoimmunity.
b. efficiently encounter antigen.
c. mature from stem cells into lymphocytes.
d. phagocytose antigen and kill it.
e. go where no cell has gone before.

Answer 3

b. efficiently encounter antigen.

Question 4

Peripheral lymphoid organs
a. are centrally located in the abdomen to protect their vital functions.
b. are designed to maximize contact between antigen and lymphocytes.
c. produce antigen-specific lymphocytes from stem cells in response to antigen.
d. sequester antigen to minimize its damage to the body.
e. store large numbers of activated effector cells for a rapid response to antigen.

Answer 4

b. are designed to maximize contact between antigen and lymphocytes.

Question 5

The PRIMARY purpose of the adaptive immune system is to
a. block all pathogens from entering the body.
b. cure allergic reactions.
c. kill tumor cells.
d. protect from disease upon re-infection with a specific pathogen.
e. reject foreign transplants.

Answer 5

d. protect from disease upon re-infection with a specific pathogen

Question 6

Rapid but non-antigen specific immune responses are produced by the
a. adaptive immune system.
b. innate immune system.
c. leukocytes.
d. lymphatic system.
e. memory response.

Answer 6

b. innate immune system.

Question 7

Vaccination protects animal (us) from infectious disease by generating memory
a. antigen.
b. lymphocytes.
c. macrophages.
d. PMNs.
e. stem cells.

Answer 7

b. lymphocytes.

Question 8

Which situation below describes an example of innate immunity?
a. antibody production by plasma cells.
b. antigen removal by cilia in the respiratory tract.
c. complement activation by antibody bound to the surface of a bacterium.
d. memory response to influenza virus
e. recognition and killing of virus-infected cells by cytotoxic T cells.

Answer 8

b. antigen removal by cilia in the respiratory tract.

Question 9

The antigen specificity of an adaptive immune response is due to
a. activation of antigen-specific lymphocytes.
b. folding of antibody to fit the pathogen.
c. lysis of only certain pathogens by neutrophils.
d. phagocytosis of only certain pathogens by macrophages.
e. production of cytokines by antigen-specific macrophages

Answer 9

a. activation of antigen-specific lymphocytes.

Question 10

Clonal selection
a. begins with inflammation.
b. occurs for all leukocytes.
c. occurs in response to self antigens.
d. results in innate immunity.
e. results in proliferation of antigen-specific lymphocytes.

Answer 10

e. results in proliferation of antigen-specific lymphocytes.

Question 11

Cytokines are NOT
a. able to induce increased blood vessel permeability.
b. antigen-specific.
c. made in response to bacterial antigens.
d. signals from one cell that affects the behavior of another cell.
e. secreted by macrophages.

Answer 11

b. antigen-specific.

Question 12

A fundamental difference between the antigen receptors on B cells (BCR) and on T cells (TCR) is their
a. different requirements for antigen presentation.
b. function following antigen binding.
c. heterogeneity from one lymphocyte to the next.
d. heterogeneity on each lymphocyte.
e. membrane location.

Answer 12

a. different requirements for antigen presentation.

Question 13

Genes for immunoglobulins (antibodies) are unlike other human genes in that
a. antibody genes are composed of introns and exons.
b. DNA for antibody molecules is inherited from only one parent.
c. gene segments must be spliced together to make each unique antibody molecule.
d. several exons encode each antibody molecule.
e. none of the above is true.

Answer 13

c. gene segments must be spliced together to make each unique antibody molecule

Question 14

Humoral immunity can be acquired passively by
a. catching a virus from a friend by shaking hands.
b. receiving a vaccine of influenza virus grown in eggs.
c. receiving serum from someone who has recovered from an infection.
d. receiving leukocytes from an immune family member.
e. sharing a soda with someone who has a cold.

Answer 14

c. receiving serum from someone who has recovered from an infection.

Question 15

Inflammation does NOT involve
a. cytokine production by macrophages.
b. migration of leukocytes out of the circulation.
c. pain.
d. secretion of antibodies.
e. swelling at the site of infection.

Answer 15

d. secretion of antibodies.

Question 16

Innate immune responses are most effective against
a. antigens resembling self antigens.
b. common antigens on bacteria.
c. genetically engineered antigens.
d. viruses.
e. viruses that have previously caused infection.

Answer 16

b. common antigens on bacteria.

Question 17

Lymphocytes acquire their antigen specificity
a. as they enter the tissues from the circulation.
b. before they encounter antigen.
c. depending on which antigens are present.
d. from contact with self antigen.
e. in the secondary lymphoid organs.

Answer 17

b. before they encounter antigen.

Question 18

A secondary immune response is NOT
a. faster than a primary response.
b. larger than a primary response.
c. longer lasting than a primary response.
d. more likely to result in increased adaptive immunity than a primary response.
e. preceded by a longer lag period than a primary response.

Answer 18

e. preceded by a longer lag period than a primary response.

Question 19

Antibody effector functions include all of the following EXCEPT
a. activating complement on bacterial surfaces to promote phagocytosis by neutrophils.
b. binding extracellular viruses to block their entry into host cells.
c. binding intracellular viruses to initiate cytotoxicity.
d. blocking uptake of bacterial toxins by host cells.
e. coating bacteria to promote their phagocytosis by neutrophils.

Answer 19

c. binding intracellular viruses to initiate cytotoxicity.

Question 20

Effector functions of complement include all of the following EXCEPT
a. attracting phagocytes to the site of infection.
b. facilitating phagocytosis of complement-coated bacteria.
c. increasing blood vessel permeability to plasma proteins.
d. lysing bacterial cells.
e. presenting antigen to B cells.

Answer 20

e. presenting antigen to B cells

Question 21

Jenner observed that milkmaids who were infected with cowpox were later immune to smallpox infections. This is an example of a(n)
a. acquired immunity of barrier skin cells.
b. active immunization with a non-related organism that causes similar symptoms.
c. innate immunity of milkmaids to smallpox.
d. memory response to a cross-reactive antigen.
e. passive immunization from contact with cow’s milk antibodies.

Answer 21

d. memory response to a cross-reactive antigen.

Question 22

Macrophages generally kill the bacteria they phagocytose by fusing lysosomes containing digestive enzymes with the phagocytic vesicle. In the case of pathogens which block this fusion, pathogen killing can still be achieved through the effector function of
a. B cells.
b. complement.
c. cytotoxic T cells.
d. opsonizing antibody.
e. Th1 cells.

Answer 22

e. Th1 cells.

Question 23

Phagocytosis
a. can be stimulated by antigen binding to complement or antibody.
b. is an antigen-specific process.
c. must be preceded by antigen processing.
d. rids the body of virus-infected cells.
e. only occurs after plasma cells begin secreting antibody.

Answer 23

a. can be stimulated by antigen binding to complement or antibody.

Question 24

Several friends who went on a picnic together developed vomiting and diarrhea from eating potato salad contaminated with Staphylococcus aureus enterotoxin. Effects of the toxin could best be counteracted by
a. antibody binding and neutralization of the toxin.
b. antibody opsonization and phagocytosis of S. aureus.
c. antibody opsonization and phagocytosis of the toxin.
d. B cell binding to S. aureus.
e. cytotoxic T cell binding and lysis of S. aureus.

Answer 24

a. antibody binding and neutralization of the toxin.

Question 25

Which of the following statements is FALSE?
a. An example of passive humoral immunity is treatment with horse anti-snake venin.
b. Antigen recognized by helper T cells must be associated with Class II MHC molecules on the surface of professional APC .
c. Each lymphocyte has many antigen binding receptors, each receptor capable of binding the same antigen.
d. Recognition and killing of virus-infected cells by cytotoxic T cells is an example of adaptive immunity.
e. The innate immune system does not deal with endogenous antigen.

Answer 25

e. The innate immune system does not deal with endogenous antigen.