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King Saud University
College of Science
Department of Biochemistry
BCH 444 – Immunology
2nd CAT(A) – 2nd Semester 1423-1424
Name:_____________________________________ No.__________________
Section 1
Answer the following questions as True [T] or False [F].
1.
In the classical pathway of complement fixation all complement
components are proteases.
[
]
The VDJ recombination produces antibodies of different classes and
subclasses.
[
]
3.
For heavy chains there are over 200 variable region genes.
[
]
4.
The kappa () chain genes are located on chromosome 22.
[
]
5.
IgG, IgA and IgE cannot be produced against the same antigen.
[
]
6.
Allotypes are antibodies which differ in their variable region, but have
the same C region.
[
]
7.
IgD and IgA can fix complement.
[
]
8.
Complement fixation can never occur in the absence of antigen-antibody
reaction.
[
]
9.
One C1q binds to one molecules of free IgM in solution.
[
]
10.
Both C3b & C5b have an Arginine residue at the C terminal which is
spasmogenic.
[
]
In the alternative pathway, no proteinases are produced.
[
]
2.
11.
12.
Antibodies have a complement binding site in the CH2 domain.
[
]
13.
The IgG-C1qC1r C1s complex hydrolyses C2 and releases
C2a peptide, which binds to C4b to form C3 convertase.
[
]
Free C3b binds to cell membrane of the bacterial cells and stimulates
opsonization.
[
]
Plasma cells are antibody producing cells and are produced in the
antigen-dependent phase of B-lymphocyte activation.
[
]
16.
The alternative pathway C3 convertase is C4b2a.
[
]
17.
In the classical pathway properdin increases the stability of
C3b Bb complex and increases its half life from 5 to 20 minutes.
[
]
Immune adherence is necessary for phagocytosis to take place and is
brought about by free C3b.
[
]
19.
Synthesis of T-lymphocytes from stem cells occurs in the thymus.
[
]
20.
Diversity (D) genes are present between V and J genes.
[
]
14.
15.
18.
Page 2 of 5
Section 2
In this Section each statement is followed by FOUR related statements which
may be all true, all false or a mixture of true and false. Put [T] in front of the
true statement and [F] in front of the false one:
1.
The allotype variations:
(a)
(b)
(c)
(d)
2.
occurs when an antibody reacts with a particulate antigen.
[ ]
requires a multivalent antigen.
[ ]
canoccur if a hapten combines with an antibody.
[ ]
occurs when the amount of antibody is almost equal to the amount of
the antigen.
[ ]
covalent bonds are formed.
a complex is formed which has a low dissociation constant.
an agglutination reactions occurs if the antigen is soluble.
complement fixation is required if the antigen is a protein
molecule.
[
[
[
]
]
]
[
]
[
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[
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[
[
]
]
[
[
[
[
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Radioimmuno diffusion (RID):
(a)
(b)
(c)
(d)
5.
]
]
]
]
When an antibody reacts with an antigen:
(a)
(b)
(c)
(d)
4.
[
[
[
[
A precipitation reaction:
(a)
(b)
(c)
(d)
3.
result from mutations in the variable region.
produce different alleles of the same antibody.
are due to presence of different heavy chains.
result from mutations in the constant region.
is a techniques to measure the concentration of an antigen.
can be used to measure the amount of IgE in a patient with
allergy.
requires an antibody to an antigen, where the antibody is
present in the gel plate.
is based on agglutination reactions.
The heavy chain genes:
(a)
(b)
(c)
(d)
are located on chromosome 14.
have 9 genes for constant regions.
have a switching (S) gene on 3’ end of each H gene.
have 12 diversity genes 5’ to the variable (v) genes.
Page 3 of 5
6.
There are several variations in antibodies:
(a)
(b)
(c)
(d)
7.
]
]
[
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stimulation of B-cells to secrete antibodies.
opsonization of bacterial cells.
activation of macrophages.
lysis of foreign cells.
[
[
[
[
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]
]
]
Factor C1q.
Factor C4.
Factor C6.
Factor C9.
[
[
[
[
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]
]
]
It is made up of 18 subunits each with 6 polypeptide chains.
Each C1q has 6 Ig receptor sites.
Each C1q subunit has 6 globular heads.
It is 400 Kd protein.
[
[
[
[
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]
]
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[
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[
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[
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C4b receptors are present on:
(a)
(b)
(c)
(d)
11.
[
[
C1q structure is complex:
(a)
(b)
(c)
(d)
10.
]
The following components of the complement system have protease
activity after activation:
(a)
(b)
(c)
(d)
9.
[
Complement system has several functions. It causes:
(a)
(b)
(c)
(d)
8.
Idiotypic variations result from changes in the variable region
of the L and H chains.
Isotypic variations produce different classes and sub-classes
of Ig’s.
IgG1 and IgG2 are allotypes for each other.
IgM has a large number of different allotypes which are
produced due to mutation in the constant region.
Red blood cells.
T-lymphocytes.
B-lymphocytes.
Neutrophils.
Complement cannot be fixed by:
(a)
(b)
(c)
(d)
IgM.
IgD.
IgA.
IgG.
Page 4 of 5
12.
Which antibodies can bind neutrophils:
(a)
(b)
(c)
(d)
13.
]
]
]
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IgM.
IgA.
IgG.
IgE.
[
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[
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[
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[
[
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Somatic mutations:
(a)
(b)
(c)
(d)
15.
[
[
[
[
The antibodies which can cross the placenta are:
(a)
(b)
(c)
(d)
14.
IgM.
IgD.
IgA.
IgG.
occur in the B-lymphocytes to produce different classes of
antibodies.
can be transmitted from the perents to their children.
normally occur in all cells of the body.
may produce antibodies with different specificities.
Complement C1:
(a)
(b)
(c)
(d)
has only 18 polypeptide chains.
can bind to IgG and IgM.
is an antibody.
has proteolytic activity after it is activated.
Page 5 of 5