Final answer:
The mismatched pair among the options provided is D) plasma cell: membrane-bound immunoglobulin, as plasma cells secrete antibodies rather than displaying them bound to their membrane.
Step-by-step explanation:
To identify the mismatched pair from the options provided, we need to examine each in the context of immunology, particularly the adaptive immune response involving B cells and the antibodies they produce.
- A) immunoglobulin: cell-surface antigen receptor – This is a correct pair since immunoglobulins, also known as antibodies when secreted, can act as antigen receptors on the surface of B cells.
- B) antibody: secreted B-cell receptor – This pair is also correct. Antibodies are secreted forms of B cell receptors known as surface immunoglobulins.
- C) agammaglobulinemia: inability to produce antibodies – This is a correct pairing since agammaglobulinemia is a condition where individuals cannot produce antibodies.
- D) plasma cell: membrane-bound immunoglobulin – This is the mismatched pair. Plasma cells, which are differentiated B cells, do not have membrane-bound immunoglobulins; instead, they secrete antibodies.
- E) plasma cell: differentiated B cell – This is a correct pair because plasma cells are indeed differentiated B cells that are specialized for antibody secretion.
Therefore, the mismatched pair is D) plasma cell: membrane-bound immunoglobulin.