Antibody

An antibody molecule contains how many polypeptide chains?

A. 2 heavy chains only

B. 2 light chains only

C. 2 heavy and 2 light chains

D. 4 heavy chains

C. 2 heavy and 2 light chains

15. The heavy and light chains of an antibody are held together primarily by:

A. Hydrogen bonds

B. Disulfide bonds

C. Ionic bonds

D. Peptide bonds

B. Disulfide bonds

Which portion of the antibody directly binds antigen?

A. Fc

B. Fab

C. CH2

D. CH3

B. Fab

17. The Fab portion consists of:

A. Two complete heavy chains

B. One light chain and part of one heavy chain

C. Two light chains only

D. Fc and carbohydrate

B. One light chain and part of one heavy chain

18. The Fc portion is composed primarily of:

A. Two portions of the heavy chains

B. Two light chains

C. One heavy and one light chain

D. Antigen fragments

A. Two portions of the heavy chains

19. Which antibody fragment CANNOT bind antigen?

A. Fab

B. Fc

C. Variable region

D. VH

B. Fc

20. The Fc region is important because it can interact with:

A. Complement and immune cells

B. DNA only

C. RBC hemoglobin

D. Antigens directly

A. Complement and immune cells

21. The term "Fc" originated because this fragment:

A. Fixes calcium

B. Forms antibodies

C. Crystallizes under specific conditions

D. Contains complement

C. Crystallizes under specific conditions

22. Papain digestion of an antibody produces:

A. One Fab and one Fc

B. Two Fab fragments and one Fc fragment

C. Two Fc fragments only

D. One intact antibody

B. Two Fab fragments and one Fc fragment

23. The hinge region of an antibody primarily provides:

A. Antigen destruction

B. Flexibility

C. Complement production

D. Antibody degradation

B. Flexibility

24. The hinge region is located between:

A. VL and CL

B. CH1 and CH2

C. CH2 and CH3

D. VH and VL

B. CH1 and CH2

25. The variable regions of an antibody are:

A. CH1 and CH2

B. CH2 and CH3

C. VH and VL

D. Fc and SC

C. VH and VL

V = variable, and the Fab region contains VH and VL.

26. The constant regions of the heavy chain include:

A. VH and VL

B. CH1, CH2, and CH3

C. Fab and Fc

D. J and SC

B. CH1, CH2, and CH3

27. The carbohydrate portion near the CH2 region helps:

A. Destroy the antigen directly

B. Increase antibody solubility and protect against degradation

C. Prevent antibody production

D. Form the light chains

B. Increase antibody solubility and protect against degradation

28. The two types of antibody light chains are:

A. Alpha and beta

B. Gamma and delta

C. Kappa and lambda

D. Mu and epsilon

C. Kappa and lambda

29. An individual antibody contains:

A. One kappa and one lambda chain

B. Either two kappa or two lambda chains

C. Four kappa chains

D. One light chain only

B. Either two kappa or two lambda chains

30. The genes for the heavy chains are located on chromosome:

A. 2

B. 6

C. 14

D. 22

C. 14

31. Kappa light-chain genes are located on chromosome:

A. 2

B. 6

C. 14

D. 22

A. 2

32. Lambda light-chain genes are located on chromosome:

A. 2 B. 6 C. 14 D. 22

D. 22

33. Bence-Jones proteins are:

A. Free heavy chains in blood

B. Free light chains found in urine

C. Complement proteins

D. MHC proteins

B. Free light chains found in urine

34. Bence-Jones proteins are classically associated with:

A. Iron deficiency anemia

B. Multiple myeloma

C. Sickle cell disease

D. Hemophilia

B. Multiple myeloma

35. Bence-Jones proteins characteristically:

A. Precipitate at 56-60°C and redissolve with further heating

B. Never change with temperature

C. Completely disappear at 56°C

D. Form crystals at room temperature

A. Precipitate at 56-60°C and redissolve with further heating

36. Which immunoglobulin makes up approximately 75-80% of total serum immunoglobulin?

A. IgA

B. IgM

C. IgG

D. IgE

C. IgG

37. Which immunoglobulin is the major antibody in the secondary immune response?

A. IgG

B. IgM

C. IgA

D. IgD

A. IgG

38. Which immunoglobulin can cross the placenta?

A. IgA

B. IgM

C. IgG

D. IgE

C. IgG

39. Which immunoglobulin has the longest half-life in blood?

A. IgG

B. IgM

C. IgA

D. IgE

A. IgG

40. Which immunoglobulin is usually the FIRST antibody produced during a primary immune response?

A. IgG

B. IgM

C. IgA

D. IgE

B. IgM

41. IgM is best described as a:

A. Monomer

B. Dimer

C. Pentamer

D. Hexamer

C. Pentamer

42. The J chain in IgM primarily:

A. Destroys antigen

B. Joins the antibody units together

C. Binds the placenta

D. Produces complement

B. Joins the antibody units together

43. How many antigen-binding sites does a typical pentameric IgM molecule have?

A. 2 B. 4 C. 5 D. 10

D. 10

Five IgM units × two binding sites each = 10 antigen-binding sites.

44. Which immunoglobulin is the most efficient agglutinator?

A. IgG

B. IgM

C. IgA

D. IgE

B. IgM

45. Which immunoglobulin is primarily associated with mucosal secretions?

A. IgG

B. IgM

C. IgA

D. IgD

C. IgA

46. Secretory IgA is usually found as a:

A. Monomer

B. Dimer

C. Pentamer

D. Tetramer

B. Dimer

47. Secretory IgA contains a secretory component that:

A. Helps transport IgA to mucosal surfaces and protects it from enzymatic degradation

B. Allows IgA to cross the placenta

C. Activates IgE

D. Converts IgA into IgM

A. Helps transport IgA to mucosal surfaces and protects it from enzymatic degradation

48. Which immunoglobulin is found on the surface of resting/immature B cells?

A. IgA

B. IgD

C. IgE

D. IgG

B. IgD

49. Which immunoglobulin is most strongly associated with Type I hypersensitivity?

A. IgG

B. IgM

C. IgA

D. IgE

D. IgE

50. Which immunoglobulin attaches to mast cells and basophils through its Fc region?

A. IgA

B. IgD

C. IgE

D. IgG

C. IgE

51. Clonal selection means that:

A. All B cells make the same antibody

B. A specific antigen selects a lymphocyte capable of responding to it

C. Antibodies destroy all lymphocytes

D. T cells randomly produce antibodies

B. A specific antigen selects a lymphocyte capable of responding to it

52. After a B cell is selected by its specific antigen, it:

A. Dies immediately

B. Multiplies to produce a clone of similar cells

C. Loses its antibody specificity

D. Becomes an RBC

B. Multiplies to produce a clone of similar cells

53. The best analogy for clonal selection is:

A. One key opening every lock

B. A specific key finding its matching lock, then making copies

C. A lock destroying all keys

D. A cell randomly changing its antibody

B. A specific key finding its matching lock, then making copies

54. A monoclonal antibody is:

A. A mixture of antibodies with many specificities

B. An antibody produced by one clone with one specificity

C. An antibody that cannot bind antigen

D. An antibody made only by T cells

B. An antibody produced by one clone with one specificity

Mono = one. Monoclonal antibodies come from one clone and recognize the same target.

55. In monoclonal antibody production, the foreign antigen is initially injected into a:

A. Human

B. Mouse

C. Bacterium

D. RBC

B. Mouse.

The foreign antigen is injected into a mouse to stimulate antibody-producing cells

Why are spleen cells used in monoclonal antibody production?

A. They can provide antibody-producing cells

B. They produce complement

C. They produce hemoglobin

D. They prevent cell division

A. They can provide antibody-producing cells

Why are myeloma cells used?

A. They produce hCG

B. They can grow indefinitely

C. They cannot divide

D. They produce MHC Class I

B. They can grow indefinitely

Myeloma cells provide the ability to keep dividing.

58. PEG is used during monoclonal antibody production to:

A. Destroy the spleen cells

B. Fuse spleen cells and myeloma cells

C. Produce antibodies directly

D. Destroy the antigen

B. Fuse spleen cells and myeloma cells

PEG = the "glue" that helps fuse the spleen and myeloma cells

The fused cell produced from a spleen cell and a myeloma cell is called a:

A. Plasma cell

B. Hybridoma

C. Lymphoma

D. Macrophage

B. Hybridoma

Why is a hybridoma ideal for monoclonal antibody production?

A. It produces many different antibodies and dies quickly

B. It produces one specific antibody and can grow indefinitely

C. It cannot reproduce

D. It only produces complement

B. It produces one specific antibody and can grow indefinitely

The hybridoma gets the best of both cells:

Spleen cell → antibody specificity 🎯

Myeloma cell → continuous growth ♾️

61. Monoclonal antibodies are particularly useful in laboratory testing because they are:

A. Nonspecific

B. Highly specific

C. Unable to bind antigen

D. Always polyclonal

B. Highly specific

Monoclonal antibodies are valuable because they recognize a very specific antigen/epitope

62. Monoclonal antibodies against the beta chain of hCG are used in:

A. Blood typing

B. Pregnancy testing

C. Coagulation testing

D. CBC testing

B. Pregnancy testing

Pregnancy tests use antibodies that recognize hCG; your notes specifically identify antibodies to the β chain of hCG.