MCQs in Immunology (21-30): Antibodies-I (Answers with Explanations)

21. All of the following are true concerningIgM antibodiesEXCEPT which one

A.they are glycoproteinB.they fix complementC.they mediate allergic reactionD.they occur on the surface of lymphocytesE.they predominate in the primary response to antigen

22.  All of the following are true concerning IgE molecules, EXCEPT which one?

A.   They are involved in mediating anti-parasitic immune responses.B.    They are the least abundant immunoglobulin in the serum.C.    They are the principal immunoglobulin class involved in allergic reactions.D.   They can affect the release of histamine and other chemical mediators.E.    They will cross the placenta and fix the complement.

23.  Which immunoglobulins are generally present in plasma at the highest concentration?

A.   IgAB.    IgDC.    IgED.   IgGE.    IgM

24.  All of the following are true aboutantibodies, EXCEPT which one?

A.   They are glycoproteins.B.    They are molecules with a single, defined amino acid sequence.C.    They fix complement.D.   They occur on the surface of B-lymphocyteE.    They predominate the primary immune responseto antigen.

25.  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 heavy chain.B.   Amino terminus of the light chain.C.  Carboxy terminus of the heavy chain.D.  Carboxy terminus of the light chain.E.   None of the above

26.  The immunoglobulin Joining chain (J-chain) is

A.   only produced by T-CellsB.    only produced by neutrophilsC.    associated with only multimeric forms of lgM and IgAD.   associated with IgE for histamine releaseE.    only produced by mast cells

27.  All of the following are true EXCEPT

A.   an antigenic determinant is a paratopeB.    An epitope is a small portion of a macromoleculeC.    An IgG antibody is bivalentD.   The class of immunoglobulin is determined by its heavy chainE.    the variable region domains contain the antigen recognition site

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

A.   IgAB.    IgDC.    IgED.   IgGE.    IgM

29.  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 administering a foreign protein or polysaccharide.E.    An antibody contains mucopolysaccharides as its major chemical component, and the synthesis of these may be elicited by administering a foreign protein or polysaccharide.

30.  The class of an immunoglobulin

A.   is determined by Class I and Class II major histocompatibility complexproteinsB.    is determined by the carbohydrate attached to the light chain isC.    determined by the antigenD.   is determined by the heavy chain typeE.    Is determined by the J-chain

Practice more MCQs:MCQ in Immunology (31-40): Complement System

Answers key of the MCQs in Immunology mentioned above are:

1.  C (they mediate allergic reaction)

2. E (They will cross the placenta and fix complement)

3. D (IgG)

4. B (They are molecules with a single, defined amino acid sequence)

5. C (Carboxy terminus of the heavy chain.)

6. C (associated with only multimeric forms of lgM and IgA)

7. A (an antigenic determinant is a paratope)

8. A (IgA)

9. D (An antibody contains protein as its major chemical component, and its synthesis may be elicited by administering a foreign protein or polysaccharide.)

10. D (is determined by the heavy chain type)