.......is secreted into the bloodstream, whereas _____ is secreted into mucus such as gastrointestinal fluid, colostrum, saliva, tears, and sweat:
a. Monomeric IgM; pentameris IgM
b. Monomeric IgA; dimeric IgA
c. Monomeric IgA; dimeric IgM
d. Dimeric IgA; monomeric IgA
Answer:
b. Monomeric IgA; dimeric IgA
Explanation:
IgA is a class of antibodies that are found mainly in body secretions. In sweat, tears, saliva, mucus, breast milk, and gastrointestinal secretions, IgA is secreted as a monomeric antibody. Smaller quantities of this class of antibodies are also present in blood and lymph. However, IgA is present in a dimeric form in the bloodstream. It makes up 10–15% of all antibodies in the blood. The main function of this class of antibodies is to give localized protection of mucous membranes against bacteria and viruses.
