Wednesday, November 27, 2013

M. Sc. Entrance Preparation Question based on M.Sc. Microbiology, TU

IMMUNOLOGY MCQ EXAM

1. 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 are glycoproteins 
E.     they mediate allergic reaction 

2. 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 
E.     cross link allergens 

3. 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.    stimulate production of interleukins 
E.     bind complement 

4. 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 
E.     antibodies to lyse cells via the perforin molecules 

5. 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 
E.     T-cell receptors are mediators of allergic reactions 

6. 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 
E.     facilitate perforin release 

7. 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 can elicit an immune response. 
E.     They contain paratopes. 

8. 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. 
E.     They are the least abundant immunoglobulin in the serum. 

9. Which of the following immunoglobulins is present normally in plasma at the highest concentration? 
A.    IgG 
B.     IgM 
C.     IgA 
D.    IgD 
E.     IgE 

10. 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 glycoproteins. 
E.     They are molecule with a single, defined amino acid sequence. 

11. 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. 
E.     None of the above 

12. 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 
E.     only produced by mast cells 


13. 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 
E.     An IgG antibody is bivalent 

14. Which immunoglobulin is the principal one found in secretions such as milk? 
A.    IgG 
B.     IgM 
C.     IgA 
D.    IgD 
E.     IgE 

15. 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.    pancreas. 
E.     intestinal tract. 

16. 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. 
E.     An antibody contains mucopolysaccharides as its major chemical component and the synthesis of these may be elicited by the administration of a foreign protein or polysaccharide. 

17. The immunoglobulin class which is the least abundant in the normal adult is 
A.    IgG 
B.     IgA 
C.     IgM 
D.    IgD 
E.     IgE. 

18. 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 
E.     results in the glycosylation of immunoglobulins 

19. 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 
E.     both the variable and constant regions change 

20. 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 
E.     Is determined by the J-chain 

21. The class of an immunoglobulin is determined by
A.    the variable region 
B.     the J-chain 
C.     the heavy chain 
D.    the carbohydrate 
E.     the T3 polypeptide complex 

22. Light chains are 
A.    specific for each class of antibody 
B.     not specific for each class of antibody 
C.     reactive with antigen 
D.    have only a constant region 
E.     are composed only of carbohydrate 

23. Each of the following is a characteristic of antibodies, EXCEPT which one? 
A.    they are proteins with variable and constant regions 
B.     they contain carbohydrates 
C.     they are only secreted by T-cells 
D.    they can combine very specifically with antigen 
E.     they are structurally organized in globular domains 

24. The T3 complex of the T-cell receptor 
A.    probably functions to transduce a signal to the cell's interior following binding of complexed antigen 
B.     binds complement 
C.     causes the histamine 
D.    mediates Immunoglobulin class switching 
E.     results in the glycosylation of immunoglobulins 

25. Cytokines are produced by cells of the immune system in response to various physiological stimuli 
A.    modulate cell function through subsequent cell differentiation or cell proliferation 
B.     facilitate cell lysis 
C.     cause glycosylation of Immunoglobins 
D.    cause histamine release 
E.     facilitate perforin release 

26. Which of the following uniquely distinguishes the T-cell receptor (TCR) from an antibody?  
A.    The TCR can bind an antigen fragment only in a trimolecular complex with either the class I or class II surface proteins of the major histocompatibility complex 
B.     The TCR can function as a cell surface antigen receptor 
C.     The TCR is composed of two different types of polypeptide chains 
D.    The TCR is capable of participating in a cytotoxic reaction. 
E.     The TCR polypeptides are composed of domains - an amino terminal variable portion at determines the binding specificity and a constant portion that determines the class of the polypeptide chain. 

27. Which of the following is NOT true of interleukins? 
A.    They are cytokines which can be produced by various cells of the immune system. 
B.     They are hormones which allow one cell to communicate with another cell. 
C.     They are in need of receptors on the target cell in order to mediate their effects. 
D.    They are able bind antigen with a high level of specificity. 
E.     They are able to modulate various aspects of the B-cell arm of immune system.

28. Which of the following is NOT true of T4 and T8 cell markers? 
A.    These are both surface glycoproteins expressed on T-cells. 
B.     These serve to distinguish different types of T-cells, e.g., helper, suppressor and cytotoxic, from each other. 
C.     These are not found associated with immunoglobulins. 
D.    The T4 proteins serve both to mediate T-cell helper function as well as the receptor for the AIDS virus. 
E.     Both of the markers are present on ALL T-cells.

29. Which of the following is NOT true of the ability of the T-cell receptor (TCR) to specifically recognize antigen? 
A.    The antigen must be "processed" first by an accessory cell of immune system in order for it to bind to the TCR. 
B.     The recognition of the antigen by the TCR can mediate helper, suppressor or cytotoxic function. 
C.     The recognition of antigen by the TCR can result in cytokine secretion and/or an increase in cell proliferation within the immune system. 
D.    The antigen is recognized by the T3-TCR complex only when it is associated with a protein of the major histocompatibility complex 
E.     Only the alpha chain of the TCR is necessary for antigen 

 30. For the following questions, choose:
A.    if only 1,2, and 3 are true
B.     if only 1 and 3 are true
C.     if only 2 and 4 are true
D.    if only 4 is true
E.     if all are true
 
 31. Complement fixation 
                        1. can be modified by the Cholera toxin 
                        2. has intrinsic Guanylate cyclase activity 
                        3. can be desensitized by phosphorylation 
                        4. is an effector function of IgG and IgM following antigen binding 

32. IgE is 
                        1. An allergy associated immunoglobulin 
                        2. the least abundant immunoglobulin in the plasma 
                        3. binds to mast cells 
                        4. can cross the placental barrier 

33. IgE 
1. is produced by mast cells 
2. is produced by B-cells 
3. is produced by T-cells 
4. binds to mast cells 

34. Which of the following are true statements 
1. IgM and IgG can fix complement 
2. IgA is a secretory immunoglobulin 
3. IgE mediates immediate hypersensitivity 
4. IgD provides most passively acquired maternal immunity
 
35. IgE is 
1. An immunoglobulin associated with some kinds of allergic reactions 
2. the least abundant typo at antibody synthesized 
3. associated with tle mast cell for histamine release 
4. produced during the primary immune response before class switching

36. Antibodies are 
1. Immunoglobulins 
2. composed of variable and constant region domains 
3. made of heavy and light chains 
4. glycoproteins 

37. The antigenic determinate 
1. is the combining site of an antibody 
2. is usually no more than five or six amino acids of the antigen 
3. is the paratope 
4. Consists of a small topological feature of the antigen

38. A critical property of an antigen is 
1. Its ability to stimulate an immune response 
2. a unique topotogical feature called an paratope 
3. a unique topological feature called an epitope 
4. not a unique topological feature called an antigenic determinant 

39. An antigenic determinant is 
1. a small topological feature of a large macromolecule such as A protein or carbohydrate 
2. specifically recognized by a epitope 
3. specifically recognized by a paratope 
4. specifically recognized by the T4 protein 

40. Immunoglobins 
1. are antibodies 
2. are classified into five major classes, i.e., IgM, IgG, IgA, IgD, IgE 
3. have a molecular specificity to recognize unique epitope 
4. possess both variable and constant region domains

41. The basic monomeric Immunoglobulin unit is 
1. composed of four; polypeptide chains 
2. only an integral membrane protein and never secreted 
3. one of five major classes 
4. synthesized by a T-cell without carbohydrate

42. Antibodies 
1. are carbohydrates 
2. are made from alpha and beta chains 
3. contain no carbohydrate 
4. contain heavy and light chains 

43. The basic monomeric immunoglobulin unit is 
1. composed of four polypeptides chains 
2. representative of a single protein type for all antibody classes 
3. able to associate with J- chain to form multimers in some cases 
4. the same structure as the T-cell antigen receptor 
44. The basic monomeric form of an immunoglobulin 
1. is a tetramer consisting of two light and two heavy chains 
2. is associated with J-chain in the IgD 
3. can occur as multimers with IgA and IgM 
4. exists only on the cell surface of B-cells
 
45. Class II MHC proteins are 
1. Recognized by the T4 (or CD4) protein 
2. used to mark a cell for killing by cytotoxic T-cells 
3. used to participate in helper function 
4. not able to carry an antigen fragment 

46. The major histocompatibility complex proteins function to 
1. degrade T4 and T8 polypeptides 
2. bind antibody for lymphokine production 
3. bind complement for cell lysis 
4. bind antigen fragments for presentation to T-cells

47. Class I MHC proteins are 
1. able to carry an antigen fragment 
2. recognized by the T8 (or CD8) protein 
3. used in combination with an antigen fragment to mark a cell for killing by cytotoxic T-cells 
4. used' to participate in helper function 

48. Which Is TRUE for BOTH the T-cell antigen receptor and the antibody 
1. They undergo class switching 
2. They can be secreted 
3. They possess J-chains 
4. They can exist as cell surface receptor, integral membrane proteins. 

49. The T-cell antigen receptor and antibody share the following features 
1. They contain variable and constant region domains 
2. They both possess paratopes that can recognize epitopes 
3. They are associated with accessory proteins necessary for signal transduction after antigen recognition 
4. They are multivalent 

50. Which properties do the T-cell receptor and the antibody share in common 
1. Both recognize antigen or antigen fragments 
2. Both are able to fix complement 
3. Both are composed of multiple polypeptide chains folded into discrete domain units 
4. Both are composed of four polypeptide chains 

51. The antigen combining site of the T-cell receptor and antibody are 
1. located at the amino terminal of the structures 
2. a pocket complementary' to the epitope 
3. capable of combining with a single antigenic determinant 
4. identified by light chain kinase 


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