What is the function of the stem part of the Y-shaped antibody (that is, the part formed by the two heavy chains joined together)?
a. It recruits immune cells to destroy the antibody antigen clump.
b. It stimulates T cells to attack bacteria and other foreign cells.
c. It attaches to foreign antigens, producing a large antibody antigen clump.
d. It attaches the antibody to the B cell membrane.
e. It has proteolytic activity, degrading viral proteins.
A; The antibodies are soluble and not attached to cells (choice d). The arms of the Y bind the antigen (choice c), producing a clump. The stems stick out and facilitate phagocytosis of the clump by macrophages.
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