Final answer:
B cells are cells that can recognize antigens alone and do not require presentation by another cell. They have antigen receptors on their surface that can bind to antigens and activate the B cell to produce antibodies. Some antigens can activate B cells without the involvement of T cells.
Step-by-step explanation:
B cells are cells that can recognize antigens alone and do not require presentation by another cell. Unlike T cells, which require the antigen to be presented on a major histocompatibility complex (MHC) molecule, B cells can recognize native, unprocessed antigen directly.
B cells have antigen receptors on their surface called B cell receptors (BCRs) that can bind to antigens. When a BCR binds to an antigen, it can activate the B cell to produce antibodies against the antigen.
Some antigens can activate B cells without the involvement of T cells. These antigens, called T cell-independent antigens, have repetitive epitopes that can activate B cells by crosslinking multiple BCRs on the surface of the B cell.