Malarial parasites are able to evade the active immune response by
a. remaining inside the host cells throughout the whole infection, thereby avoiding exposure to antibodies in the bloodstream.
b. secreting substances that block the binding and recognition of their protein by host B cells.
c. changing their coat proteins so that the host antibodies in current production cannot bind to them.
d. overwhelming the immune cells and antibodies by an enormous production of parasitic cells.
e. interfering with the production of memory cells, so that subsequent infections are just as deadly as initial ones..
B; Malarial parasites are notorious quick-change artists. The change in coat protein means that each new protein must stimulate production of a new type of B cell to produce a new type of antibody before the cells can be killed. Malarial cells can divide inside red blood cells, but will eventually burst the cell and become exposed to the antibodies in the bloodstream (choice a). While they do multiply rapidly, producing an enormous number of cells, this is a result of their effective avoidance of the immune response, not the cause.
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