Lesson 3 – Antigen exam – Brihha Assessment Platform

1. The following properties render a substance immunogenic:

a) High molecular weight

b) Chemical complexity

c) Sufficient stability and persistence after injection

d) All of the above are essential but not sufficient.

2. The protection against smallpox afforded by prior infection with
cowpox represents

a) Antigenic specificity.

b) Antigenic cross-reactivity.

c) Enhanced viral uptake by macrophages.

d) Innate immunity.

3. Haptens

a) Require carrier molecules to be immunogenic.

b) React with specific antibodies when homologous carriers are not employed.

c) Interact with specific antibody even if the hapten is monovalent.

d) All of the above.

4. Which of the following is the most antigenic?

a) Protein

b) Carbohydrate

c) Lipopolysaccharides

d) DNA

5. Which of the following antigen whose molecular weights are given
below will be the best immunogen

a) 500-1000 Dalton

b) 1000 - 5000 Dalton

c) 5000-10000 Dalton

d) Above 10,000 Dalton

6. An immunogenic determinant in a protein generally has molecular
weight

a) 500 Dalton

b) 5000 Dalton

c) 10000 Dalton

d) 45000 Dalton

7. Circulatory antigens in blood are trapped by

a) Kidney

b) Spleen

c) Lymph node

d) Payer's patches

8. Agretope is an antigen recognition site of

a) T-cells

b) B-cells

c) Antibody

d) None of the above

9. The most immunogenic class of the following molecules consists of

a) Globular proteins

b) Nucleic acids

c) Synthetic polymers such as nylon

d) Lipids

10. Haptens

a) Are not antigenic by themselves

b) Are macromolecules

c) Are usually protein-like

d) Cannot bind to an antibody molecule unless coupled to a carrier

11. Homopolymers of amino acids are poor immunogens, if at all,
because they

a) Lack sufficient size

b) Lack molecular complexity

c) Are not biodegradable

d) Both a and b

12. The ability of an antigen to induce an immune response does not
depend on the
antigen's

a) Ability to enter the thyroid

b) Degree of aggregation

c) Dose

d) Size

13. Antibody cross-reactivity is demonstrated by antibody binding to

a) Cell surface marker.

b) Hapten.

c) Hapten-carrier complex.

d) Antigen that is structurally similar to the immunogen

14. During the lag period between antigen contact and detection of
adaptive immunity,

a) Antigen is hidden from the immune system in macrophages.

b) Cellular immunity can be detected but antibodies cannot.

c) Innate immune effectors are eliminating antigen.

d) Innate immunity blocks the activation of adaptive immune effector cells.

15. For specific antigen recognition by T-cells,

a) Antigen is bound by a T-cell membrane antibody.

b) Denaturation of antigen does not reduce epitope recognition.

c) MHC molecules are not required.

d) Soluble antigen is bound directly without processing.

16. Immunogenicity

a) Depends on the ability of the native antigen to be presented by mhc.

b) Usually a property of "self" antigens such as eye tissue.

c) Is not a property of antibodies.

d) Is not a property of haptens.

17. Lymphocytes are activated by antigen in the

a) Blood stream

b) Bone marrow

c) Liver

d) Lymph nodes

18. A molecule that can be covalently linked to a non-immunogenic
antigen to make it an immunogen is called as

a) Adjuvant.

b) Carrier.

c) Hapten.

d) Mitogen.

19. A polyclonal antibody response

a) is not antigen-specific.

b) is produced only in response to polymeric antigens.

c) is produced by several B-cells recognizing different epitopes on the same antigen.

d) occurs during the lag phase of the immune response.

20. Very low doses of antigen may induce

a) Secondary response.

b) Hypersensitivity.

c) Immunological ignorance.

d) Low zone immunity.

21. Which statement about antigen epitopes is FALSE?

a) An epitope may be shared by two different antigens.

b) A protein molecule usually contains multiple epitopes.

c) B-cells bind only processed antigen epitopes.

d) Epitopes may be linear or assembled.

22. CD antigens

a) Allow leukocytes to recognize antigen.

b) Are each expressed on only one cell type.

c) Are expressed on immune cells by immunologists to "mark" them for separation.

d) Are found only on leukocytes.

23. Activation of naïve T-lymphocytes is best achieved by which
antigen presenting cells?

a) Macrophage

b) Mast cell

c) Neutrophil

d) Dendritic cells

24. Costimulatory molecules help T-cell responses by

a) Increasing T-cell activation in an antigen specific manner

b) Increasing T-cell activation regardless of the specificity of T-cell

c) Degrading antigen so it can bind to MHC

d) Binding to MHC molecules containing immunogenic peptides

25. CD4 T-cells are generally restricted by

a) MHC class - I

b) CD 1

c) MHC class - II

d) Microglobulin

26. T-cells recognise antigen

a) In a three dimensional form

b) In the solution in the plasma

c) By pattern recognition receptors

d) When presented on the surface of antigen presenting cells

27. Class III MHC genes encode for

a) CD4+T cells

b) Complement molecules

c) Cytokine molecules

d) b and c

28. Which of the following DOES NOT play a role in antigen
presentation?

a) MHC class – I molecules

b) MHC class – II molecules

c) MHC class – III molecules

d) None of the above

29. The antigen presentation by endogenous pathway involves

a) Antigen presentation to B-cells

b) Antigen presentation to Th-cells

c) Antigen presentation to cytotoxic T-cells

d) Antigen presentation to MHC II

30. Which of the following is NOT a structural chain in class I MHC

a) Alpha 1

b) Alpha 2

c) Alpha 3

d) Beta 2

31. The number of antigenic determinant site in the surface of an antigen
is called .

32. Antigens which induce auto immunity are called .

33. The MHC antigens of dogs are called .

34. The ability of a molecule to elicit an immune response is called
.

35. Antigen determinant site of a molecule is otherwise called as
.

36. An antigen unable to elicit immune response is called as .

37. The majority of antigenic substances are specific and some are
even specific within an animal species.

38. Antigens are mostly in nature.

39. , , , and are the essential features of antigenicity.

40. cannot stimulate antibody formation but can combine with
antibody molecules.

41. A measure of infectious ability of a pathogen is known as
.

42. Incomplete antigen is known as .

43. The smallest unit of antigenicity is known as .

44. The same (or) closely related antigens may sometimes occur in
different biological species and these antigens are known as
.

45. The antigen present in the individuals of the same genetic makeup is
called as .

46. The strength of binding between Ag and Ab is known as .

47. Small molecule or chemical groups that can function as epitopes
when bound to other molecules are called as .

48. Antigen

49. Autoantigen

50. Allotype

51. Epitope

52. Antigen-presenting cells

53. Co-stimulators

54. CD antigen

55. Cross-reaction

56. Dendritic cells

57. Hapten

58. Major histocompatibility complex

59. T-cell receptor (TCR

60. Differentiate Epitope, Paratope and Agretope.

61. Write in detail about characters of a good antigen.

62. Explain in detail about the antigen processing and presentation.

63. The major histocompatibility complex molecules are located in the plasma of the blood.

a. True

b. false

64. Presence of CD4 can be used to separate helper T cells from cytotoxic T cells.

a. True

b. False

65. The thymus independent type I antigens are bacterial nucleic acids.

a. True

b. Fsalse

66. Macrophages will phagocytize a foreign cell and then incorporates the foreign cell's antigen with the major histocompatibility complex II protein

a. True

b. False

67. High molecular proteins are best antigens.

a. True

b. False

68. Incomplete antigens are known as haptens.

a. True

b. False

69. Antigen antibody reaction is irreversible.

a. True

b. False

70. Protein is the very weak antigenic compare to carbohydrate and DNA.

a. True

b. False

71. Most antigens induce polyclonal response.

a. True

b. False

72. All antigens are immunogens.

a. True

b. False

73. A hapten can stimulate antibody formation but cannot combine with antibody molecule.

a. True

b. False

74. Hapten has antigenicity but no immunogenicity.

a. True

b. False

75. Lymphocytes acquire their antigenic receptors in Lymph node.

a. True

b. False

76. Epitope is an antigenic determinant.

a. True

b. False

77. Adjuvants decrease the immune response to an antigen.

a. True

b. False

78. Capsular antigen should possess immunogenicity reactivity.

a. True

b. False

79. Antigens and immunogens are synonyms.

a. True

b. False

80. What are the different techniques used to predict the antigenic
determinant sites and its advantages.

81. What are the different in-silico / bioinformatics tools to predict
immune dominant epitopes?