Plasma cells are differentiated or mature B cells capable of producing antibodies against a particular foreign substance. B cells are stimulated to differentiate into plasma cells when it binds to two receptors of helper T cell; having the T cells "help" the B cells to differentiate to plasma cells. These T cells have the antigenic information passed to them by antigen presenting cells such as dendritic cells and these will be passed to the B cells and plasma cells will produce antibodies against this specific antigen.
Water falls from a reservoir through a channel to a turbine. The water turns the turbines, which allows the generator to make electricity. Hope I helped!
