Explore topic-wise MCQs in Antigen Antibody Reaction.

This section includes 27 Mcqs, each offering curated multiple-choice questions to sharpen your Antigen Antibody Reaction knowledge and support exam preparation. Choose a topic below to get started.

1.

The class of an immunoglobulin

A. is determined by Class I and Class II major histocompatibility complex proteins
B. is determined by the carbohydrate attached to the light chain is
C. determined by the antigen
D. is determined by the heavy chain type
Answer» E.
Discussion
2.

When a B-cell undergoes immunoglobulin class switching

A. the variable region of the light chain changes, but its constant region remains the same
B. the variable region of the light chain remains the same, but its constant region changes
C. the variable region of the heavy chain remains the same but its constant region changes
D. the variable region of the heavy chain changes but its constant region remains the same
Answer» D. the variable region of the heavy chain changes but its constant region remains the same
Discussion
3.

Ring test is used for

A. C-reactive protein test
B. Ascoli's thermoprecipitation test
C. typing of streptococci and pneumococci
D. all of the above
Answer» E.
Discussion
4.

All of the following are true about antibodies, EXCEPT which one?

A. They fix complement.
B. They occur on the surface of B-lymphocyte
C. They predominate the primary immune response to antigen.
D. They are molecule with a single, defined amino acid sequence.
Answer» E.
Discussion
5.

All of the following are true with respect to IgE molecules, EXCEPT which one?

A. They are the principal immunoglobulin class involved in allergic reactions.
B. They are involved in mediating anti-parasitic immune responses.
C. They will cross the placenta and fix complement.
D. They can effect the release of histamine and other chemical mediators.
Answer» D. They can effect the release of histamine and other chemical mediators.
Discussion
6.

Which of the following immunoglobulins is present normally in plasma at the highest concentration?

A. IgG
B. IgM
C. IgA
D. IgD
Answer» B. IgM
Discussion
7.

Antigen binding sites are present in

A. Fab regions of an antibody
B. Fc region of an antibody
C. only in the light chain
D. only in the heavy chain
Answer» B. Fc region of an antibody
Discussion
8.

Monoclonal antibodies currently used clinically

A. Can protect against a wide variety of viruses and bacteria
B. Can reduce the inflammation associated with rheumatoid arthritis
C. Are derived from the plasma of individuals already immune to these organisms
D. Each have broad specificity for many antigenic determinants
Answer» C. Are derived from the plasma of individuals already immune to these organisms
Discussion
9.

A primary role for antibodies in resistance to bacterial infection is

A. Antibody dependent cell mediated cytotoxicity
B. Lysis of infected host cells
C. Activation of the alternative complement pathway
D. Opsonisation for increased uptake by phagocytic cells
Answer» E.
Discussion
10.

Antibodies recognize antigens

A. Via their hypervariable regions
B. By covalent bonding to specific epitopes
C. Have a similar high binding affinity regardless of their isotype
D. Can neutralise pathogens within host cells
Answer» B. By covalent bonding to specific epitopes
Discussion
11.

Antibody molecules

A. Are globular proteins found predominantly in the gamma region during electrophoresis
B. Recognise carbohydrates via a lectin head
C. Are produced by T cells
D. Use the Fc region to bind antigen
Answer» B. Recognise carbohydrates via a lectin head
Discussion
12.

The antibody class found at highest concentrations in serum is

A. IgE
B. IgM
C. IgD
D. IgG
Answer» E.
Discussion
13.

All of the following are true of antigen EXCEPT which one of the following?

A. They contain epitopes.
B. They will react with antibodies
C. They contain antigenic determinants
D. They contain paratopes
Answer» E.
Discussion
14.

T-cell receptors or antibodies react with antigens

A. because both are made by lymphocytes
B. because of complementary of molecular fit of both with antigen
C. because both 'have light chain and heavy chain polypeptides
D. cause histamine release
Answer» C. because both 'have light chain and heavy chain polypeptides
Discussion
15.

T-cell antigen receptors are distinguished from antibodies by which of the following

A. T-Cell receptors are glycosylated
B. T-cell receptors must interact with antigen uniquely presented by other cells but not with free antigen
C. T-Cell receptors bind various cytokines
D. T-Cell receptors bind complement to lyse cells
Answer» C. T-Cell receptors bind various cytokines
Discussion
16.

The major role of the complement system is to work in conjunction with

A. antibodies to lyse cells via the C8 and C9 components
B. the major histocompatibility complex for cell recognition
C. antibodies to opsonize cells
D. the T-cell receptor for production of lymphokines
Answer» B. the major histocompatibility complex for cell recognition
Discussion
17.

One principal function of the Class I and Class II major histocompatibility complex S proteins is to

A. transduce the signal to the T-cell interior following antigen binding
B. mediate immunoglobulin class switching
C. present antigen for recognition by the T-cell antigen receptor
D. bind complement
Answer» D. bind complement
Discussion
18.

One principal function of complement is to

A. inactivate perforins
B. mediate the release of histamine
C. Bind antibodies attached to cell surfaces and to lyse these cells
D. phagocytize antigens
Answer» D. phagocytize antigens
Discussion
19.

All of the following are true with respect to IgM antibodies EXCEPT which one

A. they fix complement
B. they occur on the surface of lymphocytes
C. they predominate in the primary response to antigen
D. they mediate allergic reaction
Answer» E.
Discussion
20.

The immunoglobulin class which is the least abundant in the normal adult is

A. IgG
B. IgA
C. IgM
D. IgE
Answer» E.
Discussion
21.

Class switching of immunoglobulins occurs

A. Usually with booster immunizations, going from IgM to IgG
B. binds complement
C. causes the histamine release
D. mediates immunoglobulin class switching
Answer» B. binds complement
Discussion
22.

Which of the following statements best characterizes an antibody?

A. An antibody contains high molecular weight RNA as its basic structure
B. An antibody is composed of protein and cannot be distinguished from the albumin fraction of the serum proteins.
C. An antibody is composed of four identical protein subunits which may be caused to dissociate by treatment with urea.
D. An antibody contains protein as its major chemical component and its synthesis may be elicited by the administration of a foreign protein or polysaccharide.
Answer» E.
Discussion
23.

Individuals unable to make the J protein found in certain immunoglobulins would be expected to have frequent infections of the

A. brain
B. blood
C. liver
D. intestinal tract
Answer» E.
Discussion
24.

Which immunoglobulin is the principal one found in secretions such as milk?

A. IgG
B. IgM
C. IgA
D. IgD
Answer» D. IgD
Discussion
25.

All of the following are true EXCEPT

A. An epitope is a small portion of a macromolecule
B. the variable region domains contain the antigen recognition site
C. an antigenic determinant is a paratope
D. The class of an immunoglobulin is determined by its heavy chain
Answer» D. The class of an immunoglobulin is determined by its heavy chain
Discussion
26.

The immunoglobulin Joining chain (J-chain) is

A. only produced by T-Cells
B. only produced by neutrophils
C. associated with only multimeric forms of lgM and IgA
D. associated with IgE for histamine release
Answer» D. associated with IgE for histamine release
Discussion
27.

The major immunoglobulin family to which a particular immunoglobulin belongs can be determined by sequential analysis of the 110 amino acids beginning from the

A. Amino terminus of the light chain
B. Carboxy terminus of the light chain
C. Amino terminus of the heavy chain
D. Carboxy terminus of the heavy chain
Answer» E.
Discussion