21. The Immune System

Which antibody class crosses the placenta from mother to child?

Which of the following is not involved in the activation of a B cell?

a. Antigen

b. Helper T cell

c. Cytokine

d. Cytotoxic T cell

Explain how active immunity and passive immunity differ.

Define antibody. Using an appropriately labeled diagram, describe the structure of an antibody monomer. Indicate and label variable and constant regions, heavy and light chains.

Match the following antibodies with the correct definition.

____IgD     

____IgM     

____IgG     

____IgA     

____IgE

a. Antibody found in secretions

b. Most common antibody; crosses the placenta

c. Antibody involved in allergies and parasitic infections

d. Pentamer and potent agglutinating agent

e. Antibody bound to the B cell plasma membrane

Ted finds out that he has been exposed to measles. He is concerned that he might have contracted the disease, so he goes to see his physician. The physician takes a blood sample and sends it to a lab for antibody levels and titers. The results show an elevated level and activity of IgM antibodies to rubella (measles) virus but very few IgG antibodies to the virus. Has Ted contracted the disease?

______ is the first immunoglobulin class produced during a primary response.

Terrence has severe asthma and allergies, and is placed on a medication that blocks the functioning of IgE. How would this medication alleviate his symptoms?

Match the following antibody classes with their description:

a)   IgA.      b)  IgG.         c)  IgE.         d)  IgM.      e)  IgD.

___ First antibody produced during primary response.

___ Protects mucous membranes.

___ Most abundant antibody.

___ Found on the surface of B cells.

___ Triggers allergic reactions to allergens.

Which of the following antibodies is involved in causing basophils to release histamine when the antibody encounters an allergen?