Deck 7: Immunological Reactions

Question 1

Antibodies are ______ that are produced by the _______.

A)lipids, adipose cells
B)carbohydrates, bone marrow cells
C)nucleic acids, hepatocytes
D)proteins, B lymphocytes

Answer 1

proteins, B lymphocytes

Question 2

Which immunoglobulin exists primarily as a pentamer and is the predominate immunoglobulin in the initial immune response to an antigen?

A)IgM
B)IgE
C)IgA
D)IgD

Answer 2

IgM

Question 3

The most potent antigens are macromolecules with molecular weights greater than:

A)1000 daltons
B)10,000 daltons
C)50,000 daltons
D)100,000 daltons

Answer 3

100,000 daltons

Question 4

In gel precipitation methods, the rate of diffusion is ________ to molecular size and _______ to concentration.

A)inversely proportional, inversely proportional
B)directly proportional, inversely proportional
C)inversely proportional, directly proportional
D)directly proportional, directly proportional

Question 5

IgG is known to fix complement, which aids in the lysis or elimination of foreign materials.Molecules in the IgG subclasses differ in their ability to fix complement.Which IgG subclass is the most active in complement fixation?

A)IgG-1
B)IgG-2
C)IgG-3
D)IgG-4

Question 6

Considering the precipitation curve shown in Figure 7-5, which phase could result in reporting falsely low results?

A)the antibody excess phase
B)the antigen-antibody equivalence phase
C)the antigen excess phase
D)none of the above; all phases would result in accurate laboratory analysis

Question 7

The portion of the immunoglobulin molecule that binds to antigens is:

A)the Fab-fragment portion
B)the Fc-fragment portion
C)the hinge portion
D)the disulfide-linkage portion

Question 8

In the laboratory analysis for amphetamine using antigen and antibody interactions as the basis for measurement, there is concern of cross-reactivity with the over-the-counter drug pseudoephedrine.What is the basis for this concern?

A)Pseudoephedrine may have a similar antigenic determinant site as amphetamine, since their chemical structures have some similarity.
B)Pseudoephedrine may block the weak, noncovalent forces that operate between antigen and antibody.
C)Pseudoephedrine may react with amphetamine to produce a product that is not recognized by the antibody.
D)Pseudoephedrine and amphetamine will not fit into the antibody-binding site at the same time.

Question 9

The portion of an antigen involved in a reaction with an antibody is known as the ____ site, and the number of these sites on an antigen is known as the antigen's _______.

A)equivalence, valency
B)equivalence, complexity
C)antigenic determinant, valency
D)antigenic determinant, complexity

Question 10

Which of the following antigenic determinants would be the most reactive?

A)an antigenic determinant located in the core of a spatially folded molecule
B)a sequential antigenic determinant
C)an antigenic determinant located on the surface of a spatially folded molecule
D)the exposed antigenic determinant of a denatured protein

Question 11

Considering the noncovalent forces that contribute to antigen and antibody attraction, ________ are the strongest and most important contributors to antigen and antibody attraction, whereas ________ are the weakest contributors to this attraction.

A)electrostatic forces, van der Waals forces
B)hydrogen bonds, electrostatic forces
C)van der Waals forces, hydrogen bonds
D)electrostatic forces, hydrogen bonds

Question 12

Is the following statement true or false? If false, identify the part of the statement that causes it to be false.
Kappa and lambda light chains differ in the amino-acid sequence of their constant regions.A given antibody always has two identical kappa light chains or two identical lambda light chains.An antibody molecule can never have both a kappa and a lambda chain.

A)true
B)false, light chains have the same amino-acid sequence in their constant regions
C)false, a given antibody can have different kappa or lambda light chains in the same molecule
D)false, an antibody can have both a kappa and lambda light chain in the same molecule

Question 13

Haptens are:

A)low-molecular-weight compounds that are unable to induce an antibody response alone
B)low-molecular-weight compounds that can induce an immune response when coupled to higher-molecular-weight immunogenic carriers
C)low-molecular-weight compounds that can react with antibodies
D)all of the above

Question 14

Which immunoglobulin can cross the placental membrane?

A)IgA
B)IgD
C)IgM
D)IgG

Question 15

When comparing an IgG molecule with a Fab fragment obtained from the same clonal population, the affinity for the antigen of interest would be ________, and the avidity of the two for the antigen of interest would be ________.

A)greater for the Fab fragment, the same
B)the same, greater for the IgG molecule
C)greater for the IgG molecule, greater for the Fab fragment
D)the same, greater for the Fab fragment

Question 16

Which immunoglobulin is associated with the physiological manifestations of allergy?

A)IgG
B)IgA
C)IgE
D)IgM

Question 17

Which immunoglobulin is the predominant immunoglobulin in body secretions such as saliva and sweat?

A)IgE
B)IgA
C)IgD
D)IgG

Question 18

Which immunoglobulin may be associated with lymphocyte differentiation?

A)IgM
B)IgA
C)IgG
D)IgD

Question 19

In radial immunodiffusion, calibrators of known concentration are analyzed along with the patient sample to allow for the quantification of antigens as illustrated in Figure 7-9.Suppose the diameter of the precipitation ring for the highest calibrator was less than the diameter for the next highest calibrator.Which of the following statements describes the likely cause for this problem?

A)The incubation temperature was not kept constant.
B)The concentration of the antibody in the gel was too high for the concentration of the highest calibrator.
C)Because the concentration of the highest calibrator is so high, diffusion through the pores of the gel was restricted.
D)The concentration of the highest calibrator was greater than the concentration of the antibody in the gel.

Question 20

Which of the following statements best describes the region of the immunoglobulin molecule that is responsible for specific binding to the antigen?

A)The constant regions of the heavy and light chains in the Fab fragment interact to form a specific antigen-combining site.
B)The variable regions of the light and heavy chains in the Fab fragment interact to form a specific antigen-combining site.
C)The constant regions of the heavy and light chains in the Fc fragment interact to form a specific antigen-combining site.
D)The variable regions of the light and heavy chains in the Fc fragment interact to form a specific antigen-combining site.