Final answer:
B cells bind to intact antigens directly and can function as APCs, producing antibodies, while T cells recognize processed antigens presented by MHC molecules and are involved in the cell-mediated immune response.
Step-by-step explanation:
The differences between B and T cells in terms of the antigens they bind are crucial for their functions in the immune system. B cells have antigen receptors on their surface to bind intact antigens and are also able to function as antigen-presenting cells (APCs). They can recognize pathogens directly and produce antibodies specific to these antigens. On the other hand, T cells recognize antigens that have been processed and presented by other APCs in the context of MHC molecules; they do not bind antigens directly. T cells, therefore, are more involved in recognizing and responding to cells that are infected or abnormal rather than free-floating antigens.
Bacterial carbohydrate and lipid molecules can activate B cells independently from T cells. Naive B cells play a role in the humoral immune response by producing antibodies, while naive T cells are involved in the cell-mediated immune response that includes direct destruction of pathogens or infected cells.