1 | Page
Immunology & Serology Questions and
Answers
*From the following, identify a specific component of the adaptive
immune system that is formed in response to antigenic
stimulation:
A. Lysozyme
B. Complement
C. Commensal organisms
D. Immunoglobulin Ans: *D. Immunoglobulin is a specific part of
the adaptive immune system and is formed only in response to a
specific antigenic stimulation. Complement, lysozyme, and
commensal organisms all act nonspecifically as a part of the
adaptive immune system. These three components do not require
any type of specific antigenic stimulation.
*Which two organs are considered the primary lymphoid organs in
which immunocompetent cells originate and mature?
A. Thyroid and Peyer's patches B. Thymus and bone marrow
C. Spleen and mucosal-associated lymphoid tissue (MALT)
D. Lymph nodes and thoracic duct Ans: *B. The bone marrow and
thymus are considered primary lymphoid organs because
immunocompetent cells either originate or mature in them. Some
© 2025 All rights reserved
, 2 | Page
immunocompetent cells mature or reside in the bone marrow (the
source of all hematopoietic cells) until transported to the thymus,
spleen, or Peyer's patches, where they process antigen or
manufacture antibody. T lymphocytes, after originating in the
bone marrow, travel to the thymus to mature and differentiate.
*What type of B cells are formed after antigen stimulation?
A. Plasma cells and memory B cells
B. Mature B cells
C. Antigen-dependent B cells
*A Mature B cells exhibit surface immunoglobulin that may cross
link a foreign antigen, thus forming the activated B cell and
leading to capping and internalization of antigen. The activated B
cell gives rise to plasma cells that produce and secrete
immunoglobulins and memory cells that reside in lymphoid
organs.D. Receptor-activated B cells Ans: *A. Mature B cells
exhibit surface immunoglobulin that may cross link a foreign
antigen, thus forming the activated B cell and leading to capping
and internalization of antigen. The activated B cell gives rise to
plasma cells that produce and secrete immunoglobulins and
memory cells that reside in lymphoid organs.
*T cells travel from the bone marrow to the thymus for
maturation. What is the correct order of the maturation sequence
for T cells in the thymus?
A. Bone marrow to the cortex; after thymic education, released
back to peripheral circulation
B. Maturation and selection occur in the cortex; migration to the
medulla; release of mature T cells to secondary lymphoid organs
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C. Storage in either the cortex or medulla; release of T cells into
the peripheral circulation
D. Activation and selection occur in the medulla; mature T cells are
stored in the cortex until activated by antigen Ans: *B. Immature
T cells travel from the bone marrow to the thymus to mature into
functional T cells. Once in the thymus, T cells undergo a selection
and maturation sequence that begins in the cortex and moves to
the medulla of the thymus. Thymic factors such as thymosin and
thymopoietin and cells within the thymus such as macrophages
and dendritic cells assist in this sequence. After completion of the
maturation cycle, T cells are released to secondary lymphoid
organs to await antigen recognition and activation.
*Which cluster of differentiation (CD) marker appears during the
first stage of T-cell development and remains present as an
identifying marker for T cells?
A. CD1
B. CD2
C. CD3
D. CD4 or CD8 Ans: *B. The CD2 marker appears during the first
stage of T-cell development and can be used to differentiate T cells
from other lymphocytes. This T-lymphocyte receptor binds sheep
red blood cells (RBCs). This peculiar characteristic was the basis
for the classic E rosette test once used to enumerate T cells in
peripheral blood. CD2 is not specific for T cells, however, and is
also found on large granular lymphocytes (LGL or natural killer
[NK] cells).
*Which markers are found on mature, peripheral helper T cells? A.
CD1, CD2, CD4
B. CD2, CD3, CD8
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C. CD1, CD3, CD4
D. CD2, CD3, CD4 Ans: *D. Mature, peripheral helper T cells have
the CD2 (E rosette), CD3 (mature T cell), and CD4 (helper) markers.
*Which T cell expresses the CD8 marker and acts specifically to kill
tumors or virally infected cells?
A. Helper T
B. T suppressor
C. T cytotoxic
D. T inducer/suppressor Ans: *C. T cytotoxic cells recognize
antigen in association with major histocompatibility complex
(MHC) class I complexes and act against target cells that express
foreign antigens. These include viral antigens and the human
leukocyte antigens (HLA) that are the target of graft rejection
*How are cytotoxic T cells (TC cells) and natural killer (NK) cells
similar?
A. Require antibody to be present B. Effective against virally
infected cells
C. Recognize antigen in association with HLA class II markers
D. Do not bind to infected cells Ans: *B. Both TC and NK cells are
effective against virally infected cells, and neither requires
antibody to be present to bind to infected cells. NK cells do not
exhibit MHC class restriction, whereas activation of TC cells
requires the presence of MHC class I molecules in association with
the viral antigen.
*What is the name of the process by which phagocytic cells are
attracted to a substance such as a bacterial peptide?
© 2025 All rights reserved
Immunology & Serology Questions and
Answers
*From the following, identify a specific component of the adaptive
immune system that is formed in response to antigenic
stimulation:
A. Lysozyme
B. Complement
C. Commensal organisms
D. Immunoglobulin Ans: *D. Immunoglobulin is a specific part of
the adaptive immune system and is formed only in response to a
specific antigenic stimulation. Complement, lysozyme, and
commensal organisms all act nonspecifically as a part of the
adaptive immune system. These three components do not require
any type of specific antigenic stimulation.
*Which two organs are considered the primary lymphoid organs in
which immunocompetent cells originate and mature?
A. Thyroid and Peyer's patches B. Thymus and bone marrow
C. Spleen and mucosal-associated lymphoid tissue (MALT)
D. Lymph nodes and thoracic duct Ans: *B. The bone marrow and
thymus are considered primary lymphoid organs because
immunocompetent cells either originate or mature in them. Some
© 2025 All rights reserved
, 2 | Page
immunocompetent cells mature or reside in the bone marrow (the
source of all hematopoietic cells) until transported to the thymus,
spleen, or Peyer's patches, where they process antigen or
manufacture antibody. T lymphocytes, after originating in the
bone marrow, travel to the thymus to mature and differentiate.
*What type of B cells are formed after antigen stimulation?
A. Plasma cells and memory B cells
B. Mature B cells
C. Antigen-dependent B cells
*A Mature B cells exhibit surface immunoglobulin that may cross
link a foreign antigen, thus forming the activated B cell and
leading to capping and internalization of antigen. The activated B
cell gives rise to plasma cells that produce and secrete
immunoglobulins and memory cells that reside in lymphoid
organs.D. Receptor-activated B cells Ans: *A. Mature B cells
exhibit surface immunoglobulin that may cross link a foreign
antigen, thus forming the activated B cell and leading to capping
and internalization of antigen. The activated B cell gives rise to
plasma cells that produce and secrete immunoglobulins and
memory cells that reside in lymphoid organs.
*T cells travel from the bone marrow to the thymus for
maturation. What is the correct order of the maturation sequence
for T cells in the thymus?
A. Bone marrow to the cortex; after thymic education, released
back to peripheral circulation
B. Maturation and selection occur in the cortex; migration to the
medulla; release of mature T cells to secondary lymphoid organs
© 2025 All rights reserved
, 3 | Page
C. Storage in either the cortex or medulla; release of T cells into
the peripheral circulation
D. Activation and selection occur in the medulla; mature T cells are
stored in the cortex until activated by antigen Ans: *B. Immature
T cells travel from the bone marrow to the thymus to mature into
functional T cells. Once in the thymus, T cells undergo a selection
and maturation sequence that begins in the cortex and moves to
the medulla of the thymus. Thymic factors such as thymosin and
thymopoietin and cells within the thymus such as macrophages
and dendritic cells assist in this sequence. After completion of the
maturation cycle, T cells are released to secondary lymphoid
organs to await antigen recognition and activation.
*Which cluster of differentiation (CD) marker appears during the
first stage of T-cell development and remains present as an
identifying marker for T cells?
A. CD1
B. CD2
C. CD3
D. CD4 or CD8 Ans: *B. The CD2 marker appears during the first
stage of T-cell development and can be used to differentiate T cells
from other lymphocytes. This T-lymphocyte receptor binds sheep
red blood cells (RBCs). This peculiar characteristic was the basis
for the classic E rosette test once used to enumerate T cells in
peripheral blood. CD2 is not specific for T cells, however, and is
also found on large granular lymphocytes (LGL or natural killer
[NK] cells).
*Which markers are found on mature, peripheral helper T cells? A.
CD1, CD2, CD4
B. CD2, CD3, CD8
© 2025 All rights reserved
, 4 | Page
C. CD1, CD3, CD4
D. CD2, CD3, CD4 Ans: *D. Mature, peripheral helper T cells have
the CD2 (E rosette), CD3 (mature T cell), and CD4 (helper) markers.
*Which T cell expresses the CD8 marker and acts specifically to kill
tumors or virally infected cells?
A. Helper T
B. T suppressor
C. T cytotoxic
D. T inducer/suppressor Ans: *C. T cytotoxic cells recognize
antigen in association with major histocompatibility complex
(MHC) class I complexes and act against target cells that express
foreign antigens. These include viral antigens and the human
leukocyte antigens (HLA) that are the target of graft rejection
*How are cytotoxic T cells (TC cells) and natural killer (NK) cells
similar?
A. Require antibody to be present B. Effective against virally
infected cells
C. Recognize antigen in association with HLA class II markers
D. Do not bind to infected cells Ans: *B. Both TC and NK cells are
effective against virally infected cells, and neither requires
antibody to be present to bind to infected cells. NK cells do not
exhibit MHC class restriction, whereas activation of TC cells
requires the presence of MHC class I molecules in association with
the viral antigen.
*What is the name of the process by which phagocytic cells are
attracted to a substance such as a bacterial peptide?
© 2025 All rights reserved
