Chapter 16 Adaptive Immunity
16.1 Multiple Choice Questions
1) Antigens are
A) specific molecules, or parts of molecules, that the body recognizes as foreign.
B) proteins the body produces against invading substances.
C) cells that protect the body against invaders.
D) proteins on the surface of our cells to which pathogens attach.
E) enzymes secreted to destroy a pathogen’s cell wall.
2) Adaptive immunity is sometimes also called acquired immunity. Which of the following
statements provides a basis for the alternative name?
A) Lymphocytes of the adaptive immune system are highly specific for a single antigenic
determinant.
B) Activated lymphocytes produce daughter cells that are identical in specificity and function.
C) To become activated, lymphocytes require exposure to the antigenic determinant for which
they are specific.
D) Activated lymphocytes may persist for years in the body.
E) Lymphocytes reactive to normal body components are removed.
3) Which of the following is an exogenous antigen?
A) a bacterium inside a cell
B) a virus inside a cell
C) a bacterium outside a cell
D) a noninfected human cell
E) the malaria parasite inside a red blood cell
4) Which of the following statements about lymphocytes is FALSE?
A) Once they are mature, they migrate to secondary lymphoid organs.
B) B and T lymphocytes can be differentiated under the bright-field light microscope.
C) Lymphocytes have integral surface proteins by which they can be recognized.
D) The glycoproteins on the surface of a lymphocyte are designated with the prefix CD, for
“cluster of differentiation.”
E) Lymphocytes have different types of CD molecules in their cytoplasmic membranes.
5) The majority of mature, self-tolerant lymphocytes are found in
A) the MALT.
B) lymph nodes.
C) the thymus.
D) the spleen.
E) the tonsils.
6) Which of the following is NOT included in the MALT?
A) the appendix
B) the spleen
C) Peyer’s patches
D) lymphoid tissue in the respiratory tract
E) lymphoid tissue in the small intestine
7) The white blood cells primarily responsible for adaptive immunity are
A) NK lymphocytes and neutrophils.
B) B lymphocytes and T lymphocytes.
C) macrophages and eosinophils.
D) macrophages and neutrophils.
E) neutrophils and dendritic cells.
8) You step on something in the yard resulting in a puncture wound that does not bleed freely.
Antigens from any microbes that entered the wound will most likely end up in the
A) appendix.
B) lymph nodes of the groin.
C) lymph nodes of the neck (cervical).
D) lymph nodes of the armpit (axilla).
E) spleen.
9)
The type of immunoglobulin illustrated in Figure 16.1 is
A) IgE.
B) IgG.
C) IgA.
D) IgM.
E) IgD.
10) Which of the following statements concerning the chemical structure of an antibody is
FALSE?
A) Antibodies are formed of four polypeptide chains.
B) Antibodies have two long peptide chains known as heavy chains.
C) Antibodies have two short peptide chains known as light chains.
D) The stem and arm are connected by a hinge.
E) The heavy and light chains are connected by hydrogen bonds.
11) The antibody-binding site of an antibody is made up of
A) portions of both of the heavy chains only.
B) the variable regions of the heavy chains.
C) the light chains only.
D) the variable regions of both light and heavy chains.
E) one heavy chain.
12) The antibody immune response is attributed to the action of
A) monocytes.
B) T lymphocytes.
C) B lymphocytes.
D) neutrophils.
E) macrophages.
13) Which of the following statements regarding antibody function is FALSE?
A) They can prevent virus attachment to host cells.
B) They can facilitate phagocyte attack on bacteria with a capsule (glycocalyx).
C) They can penetrate host cells to bind intracellular antigens.
D) They can facilitate cytotoxic attack by natural killer lymphocytes.
E) They can bind more than one pathogen at a time, forming complexes.
14) Secretory IgA antibodies are unique because they
A) have unique light chains.
B) are Y-shaped molecules.
C) are present in the plasma.
D) are connected with J chains and short polypeptides to form dimers.
E) are present in lymph nodes.
15) The most prevalent type of antibody in the blood is
A) IgD.
B) IgM.
C) IgA.
D) IgG.
E) IgE.
16) Which of the following function in agglutination?
A) IgA antibodies
B) IgG antibodies
C) IgE antibodies
D) IgD antibodies
E) IgA and IgG antibodies
17) Which of the following statements concerning B cell receptors (BCRs) is FALSE?
A) They are formed in response to an encounter with an antigen.
B) They are complementary in shape to a specific antigenic determinant that they may or may
not encounter.
C) They are bound to the surface of B lymphocytes and have two antigen-binding sites.
D) Each B lymphocyte is randomly generated with antibody variable regions that determine its
BCR.
E) Scientists estimate that each person forms at least 1011 different types of B lymphocytes
with distinct BCRs.
18) Which of the following statements about T lymphocytes is FALSE?
A) T lymphocytes produce antibody molecules.
B) T lymphocytes directly attack cells and produce the cell-mediated immune response.
C) T lymphocytes are called such because they mature in the thymus.
D) T lymphocytes have TCRs that recognize antigen only if it is bound to MHC.
E) There are three types of T lymphocytes.
19) Which of the following cytokines act as a signal between leukocytes?
A) growth factors
B) interferons
C) interleukins
D) tumor necrosis factors
E) chemokines
20) Clonal deletion of developing T lymphocytes takes place in which location(s) in the body?
A) the bone marrow
B) the spleen
C) the liver
D) both the bone marrow and the spleen
E) the thymus
21)
Figure 16.2 illustrates an interaction between a(n)
A) antigen presenting cell and a B lymphocyte.
B) antigen presenting cell and a T lymphocyte.
C) NK cell and its target cell.
D) CTL and its target cell.
E) antigen presenting cell and a plasma cell.
22) Major histocompatibility antigens are
A) antigens that provoke allergic reactions.
B) antigens that must be processed to be recognized by the immune system.
C) antigens attached to foreign invaders.
D) autoantigens involved in epitope recognition.
E) not really antigens, but rather antibodies produced to mask foreign antigens.
23) Which of the following statements concerning specific immunity is FALSE?
A) It is the third line of defense.
B) It has memory.
C) It changes little with repeated exposure to the same pathogen.
D) It is acquired.
E) It is the body’s ability to respond to specific invading pathogens.
24) Class I MHC molecules are essential for
A) presentation of endogenous antigens.
B) recognition of chemokines.
C) detection of IL-2.
D) recognition of class II MHC.
E) presentation of exogenous antigens.
25) Class II MHC are found on
A) the skin.
B) red blood cells.
C) cytoplasmic membranes of nucleated cells.
D) muscle cells.
E) professional antigen-presenting cells.
26) Exogenous antigens are processed for immune recognition by ________ cells.
A) dendritic
B) all nucleated
C) macrophage
D) helper T
E) dendritic and macrophage
27) Which of the following recognizes and binds to MHC I proteins and helps stabilize the
binding of epitopes to T cell receptors?
A) CD8
B) MHC I
C) CD26
D) CD4
E) CD95
28) Which of the following statements concerning plasma cells is FALSE?
A) They live for many years and function as memory cells.
B) They are descended from activated B cells.
C) They can produce large quantities of antibodies on a daily basis.
D) They secrete a single type of antibody molecule specific for a single epitope.
E) The antibodies they produce can remain in circulation for weeks.
29) Enhanced immune responses to subsequent exposures to an antigen to which the body has
already been exposed are known as ________ responses.
A) third-degree immune
B) allergic
C) primary immune
D) memory
E) autoimmune
30) Which of the following statements regarding the cell-mediated immune response is TRUE?
A) Cytotoxic T lymphocytes do not require antigen presentation to become activated.
B) Cytotoxic T lymphocytes interact with antibodies that have bound antigen to identify their
target.
C) Helper T lymphocytes have no role in the activation of cytotoxic T lymphocytes.
D) Cytotoxic T lymphocytes kill by producing hydrogen peroxide.
E) A single cytotoxic T lymphocyte can kill many target cells.
31) The protozoan that causes malaria is an intracellular parasite of red blood cells (RBCs). An
adaptive immune response to this parasite is problematic because
A) red blood cells do not produce MHC and, therefore, do not display the fact that they have
been infected by presenting antigen.
B) the parasite damages leukocytes along with RBCs.
C) RBCs normally produce cytokines necessary for adaptive immune response, which this
infection prevents.
D) complement cannot effectively destroy RBCs.
E) RBCs never enter lymphoid tissue.
32) The perforin-granzyme pathway involves
A) the production of fever, which kills the pathogen.
B) the production of antibodies toward the invading pathogen.
C) the synthesis of special cell-killing proteins that act on infected or abnormal cells.
D) presenting the foreign antigen to B cells.
E) binding CD95L to infected cells, which eventually leads to cell apoptosis.
33) The immunological synapse refers to the
A) interaction between a T cell and an antigen-presenting cell to produce a specialized contact
area for communication between these cells.
B) activation of a B cell to become a plasma cell.
C) interaction between lymphocytes and foreign antigens to produce memory cells.
D) binding of a monocyte or macrophage to antigen so that it can act as an antigen-presenting
cell.
E) interaction of the many cytokines produced by different immunological cells.
34) What type of immunity is produced by the body when a person contracts a disease?
A) innate immunity
B) naturally acquired passive immunity
C) artificially acquired active immunity
D) artificially acquired passive immunity
E) naturally acquired active immunity
35) A sick child may have influenza or RSV. These virus infections have different treatment
options, so the physician requests antibody titer tests. The results are as follows: anti-influenza
antibodies are primarily IgM, and anti-RSV antibodies are all IgA and IgG. Which of the
following is the most appropriate interpretation?
A) The child has a current RSV infection and was previously exposed to influenza.
B) The child currently has influenza and has previously been exposed to RSV.
C) The child has concurrent influenza and RSV infections.
D) The child has neither influenza nor RSV.
E) The results do not provide sufficient data to draw a conclusion.
36) Which of the following statements regarding the lymphatic system is FALSE?
A) Lymph fluid is similar to blood plasma.
B) The lymphatic vessels contract to move lymphatic fluid.
C) The lymphatic vessels have valves to control the direction of fluid flow.
D) The lymphatic system begins with highly permeable capillaries.
E) Fluid flows through lymph nodes on its way to the bloodstream.
37) What is the role of interleukins?
A) chemotaxis of leukocytes
B) production of virally infected cells
C) ensuring production of enough leukocytes
D) signaling between leukocytes
E) complement activation
38) Which of the following cytokines promotes the development of a cell-mediated immune
response?
A) alpha interferon
B) chemokines
C) tumor necrosis factor (TNF)
D) IL-4 (interleukin-4)
E) IL-12
39) What is the result when a dendritic cell phagocytizes a microbe and processes it?
A) activation of the dendritic cell to become a plasma cell
B) display of epitope-MHC I complexes on the surface of the cell
C) suppression of the immune response to the microbe
D) display of microbial fragments with CD8 glycoproteins
E) display of microbial epitope-MHC II complexes on the cell surface
40) Which of the following is TRUE of chemokines?
A) They ensure production of enough leukocytes.
B) They are involved in B lymphocyte activation and differentiation.
C) They are chemotactic factors for leukocytes.
D) They cause basophils and eosinophils to degranulate.
E) They are substances used to signal between leukocytes.
41) Vaccination triggers an immune response which produces ________ immunity.
A) artificial passive
B) natural passive
C) natural active
D) artificial active
E) both active and passive
42) Which of the following best describes IgM antibodies?
A) They cause basophils and eosinophils to degranulate.
B) They are the most common type of antibody in the blood during the initial phases of an
immune response.
C) They are the antibody class found in body secretions.
D) They interact with phagocytes and NK cells.
E) They can cross the placenta to provide passive immunity.
43) IgE antibodies are best described as
A) a cause of basophil and eosinophil degranulation.
B) the antibodies found in body secretions.
C) those involved in complement activation.
D) the trigger for antibody-dependent cellular toxicity (ADCC).
E) the most common type of antibody in the blood during the initial phases of an immune
response.
44) How is the development of autoimmunity normally prevented?
A) T lymphocytes that respond to autoantigens in the thymus undergo clonal deletion.
B) T lymphocytes require a specific set of cytokine signals to become activated.
C) Regulatory T cells suppress autoimmune responses.
D) Clonal deletion of T cells and regulatory T cell suppression prevent autoreactive T cell
activation.
E) Clonal deletion of T cells, lack of necessary cytokine signals, and regulatory T cell
suppression prevent activation of autoreactive T cells.
45) Which of the following is the result when a CTL interacts with a virally infected cell?
A) The cell releases interferon-gamma (INF-γ).
B) The cell undergoes apoptosis.
C) The CTL produces oxidizing chemicals.
D) The CTL produces IL-12.
E) The cell produces MHC II with epitope attached.
16.2 True/False Questions
1) Large molecules such as polymers make good antigens.
2) Molecules with a molecular mass less than 5000 daltons can become antigens when they
bind to carrier molecules.
3) IgG antibodies kill pathogens both directly and indirectly.
4) The MALT lacks the tough outer capsule of a lymph node but functions in the same way.
5) A single B lymphocyte can recognize multiple antigenic determinants.
6) Immature B lymphocytes undergo clonal deletion in the bone marrow.
7) CTLs use the CD95 molecule to recognize their epitope.
8) Cytokines are soluble regulatory proteins that act as intercellular signals and include
substances such as interleukins, interferon, and growth factors.
9) During an infection with Listeria, an intracellular bacterium, APCs will present antigen on
MHC II molecules.
10) When a T cell’s CD95L binds to the CD95 on a target cell, antibodies are formed.
16.3 Short Answer Questions
1) The ability of the body to respond faster and more effectively to a second exposure to
pathogens is called immunologic (memory/synapse/tolerance).
2) An antigen produced by a pathogen while living inside a cell is known as an (auto-
/endogenous/exogenous) antigen.
3) The body recognizes antigens by the three-dimensional shapes of regions known as
(antigenic/antibody/immunologic) determinants.
4) The (constant/end/variable) regions from the light and heavy chains of an antibody combine
to form antigen-binding sites.
5) The delay in the initial adaptive immune response to pathogen is largely due to the
(inducibility/memory/specificity) of adaptive immunity.
6) T lymphocytes mature in the (bone marrow/lymph node/thymus).
7) Plasma cells produce (antibody/chemokine/cytotoxic) molecules.
8) TCRs only recognize antigens presented by APC; therefore, (BCR/MHC/Th1) molecules
ultimately determine which epitopes elicit an immune response.
9) The surface of each B lymphocyte is covered with about 250,000 to 500,000 identical copies
of (BCR/MHC/TCR).
10)
The antibody function known as (agglutination/neutralization/opsonization) is illustrated in
Figure 16.3.
11) Professional antigen-presenting cells (APCs) include B cells, macrophages, and
(dendritic/plasma/T) cells.
12) T lymphocytes that have both CD4 and CD25 are (cytotoxic/helper/regulatory) T cells.
13) Cytotoxic T lymphocytes insert (CD95/lectin/perforin) into the membranes of the cells they
target as a first step in killing.
14) B cells are activated when they interact with (antigen-presenting/Th1/Th2) cells.
15) The IgG molecules which cross the placenta and circulate in a baby’s bloodstream provide
the baby with natural (active/innate/passive) immunity.
16.4 Essay Questions
1) Discuss the importance of there being two types of adaptive immune responses (antibody
and cell-mediated).
2) A variety of molecular components of the adaptive immune system bind epitopes (antigenic
determinants). Compare and contrast the binding of epitopes by antibody molecules, T cell
receptors (TCRs), and MHC molecules, and describe the consequences of the different
interactions.
3) What are the steps involved in B cell activation?
4) Compare and contrast clonal deletion and clonal selection of B lymphocytes.
5) Describe the mechanisms of action of antibodies.