B cell receptors are essentially membrane-bound immunoglobulins that perform which function?

B cell receptors are essentially membrane-bound immunoglobulins that perform which function?

• A. T cell receptor
• B. Major histocompatibility complex class I
• C. Cytotoxic granules
• D. B-cell receptor (membrane-bound immunoglobulin)

Answer: (D)

B cell receptors function as membrane-bound immunoglobulins that recognize specific antigens and trigger B cell activation. When the receptor binds its antigen, it sends activation signals through the associated signaling chains, prompting the B cell to proliferate and differentiate into antibody-producing plasma cells and memory B cells. The BCR also internalizes the bound antigen for processing and presentation to helper T cells, linking antibody responses to T cell help. This role is distinct from T cell receptors (which function on T cells), MHC class I molecules (which present peptides to CD8+ T cells), and cytotoxic granules (secreted cytotoxic contents), making the membrane-bound immunoglobulin structure of the BCR the best match for the function described.

B cell receptors function as membrane-bound immunoglobulins that recognize specific antigens and trigger B cell activation. When the receptor binds its antigen, it sends activation signals through the associated signaling chains, prompting the B cell to proliferate and differentiate into antibody-producing plasma cells and memory B cells. The BCR also internalizes the bound antigen for processing and presentation to helper T cells, linking antibody responses to T cell help. This role is distinct from T cell receptors (which function on T cells), MHC class I molecules (which present peptides to CD8+ T cells), and cytotoxic granules (secreted cytotoxic contents), making the membrane-bound immunoglobulin structure of the BCR the best match for the function described.