20. Adaptive Immunity

Which term describes antibodies binding to a virus preventing it from attaching to host cells?

The study of antigen-antibody reactions is referred to as _____.

Which of the following is NOT a protective outcome of antibody-antigen binding?

DRAW IT Label components of the direct and indirect ELISA tests in the following situations. Which test is direct? Which test provides definitive proof of disease?

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How does the antigen in an agglutination reaction differ from that in a precipitation reaction?

Put the following in the correct sequence to elicit an antibody response: (1) TH cell produces cytokines; (2) B cell contacts antigen; (3) antigen fragment goes to surface of the B cell; (4) TH recognizes antigen fragment and MHC; (5) B cell proliferates.

a. 1, 2, 3, 4, 5

b. 5, 4, 3, 2, 1

c. 3, 4, 5, 1, 2

d. 2, 3, 4, 1, 5

e. 4, 5, 3, 1, 2

Explain the effects of excess antigen and antibody on the precipitation reaction. How is the precipitin ring test different from an immunodiffusion test?

Match the following serological tests in column A to the descriptions in column B.

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Match each of the following tests in column A to its positive reaction in column B.

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The examples in questions 1 and 2 are

a. direct tests.

b. indirect tests.

Use the following choices to answer questions 4 and 5:

a. anti-Brucella

b. Brucella

c. substrate for the enzyme

Which is the third step in a direct ELISA test?

NAME IT A purified protein from Mycobacterium tuberculosis is injected into a person’s skin. A hardened, red area develops around the injection site within 3 days.

Use the following choices to answer questions 4 and 5:

a. anti-Brucella

b. Brucella

c. substrate for the enzyme

Which item is from the patient in an indirect ELISA test?

In an immunodiffusion test, a strip of filter paper containing diphtheria antitoxin is placed on a solid culture medium. Then bacteria are streaked perpendicular to the filter paper. If the bacteria are toxigenic,

a. the filter paper will turn red.

b. a line of antigen–antibody precipitate will form.

c. the cells will lyse.

d. the cells will fluoresce.

e. none of the above

Use the following choices to answer questions 1 and 2:

a. hemolysis

b. hemagglutination

c. hemagglutination inhibition

d. no hemolysis

e. precipitin ring forms

Patient’s serum, influenza virus, sheep red blood cells, and anti-sheep red blood cells are mixed in a tube. What happens if the patient has antibodies against influenza?