Final answer:
Special proteins made by lymphocytes to combat pathogens are called antibodies, primarily produced by B cells when activated by antigens. T cells provide cellular immunity without producing antibodies, and both cell types can form memory cells for a rapid response to repeated infections.
Step-by-step explanation:
Special proteins that are made by lymphocytes to fight invaders are known as antibodies. These antibodies are produced by a specific type of lymphocyte called B cells. When B cells are activated by the presence of antigens, which are unique markers on the surface of pathogens, they differentiate into plasma cells and secrete antibodies. These antibodies have the unique ability to specifically bind to the antigens they were designed to recognize, thereby neutralizing or marking the pathogen for destruction by other immune cells.
T cells, another type of lymphocyte, provide cellular immunity by directly attacking infected or diseased cells. Unlike B cells, they do not produce antibodies, but they play a crucial role in the immune response by regulating the action of other immune cells and directly destroying target cells. Both B cells and T cells can form memory cells after initial exposure to a pathogen, which allows for a faster and more efficient response to subsequent infections by the same pathogen.