Question

The membrane of mature B cells have

• A. Both IgG and IgM
• B. Both IgG and IgD
• C. Both IgM and IgE
• D. Both IgM and IgD

Answer 1

The correct option is D Both IgM and IgD

Antibodies are immunoglobulin (Ig) molecules that are produced by the body to counter the invasion of any foreign material/ antigen into the body. B-lymphocytes or B cells are the main cells that produce the antibodies in blood in response to any forign invaders/antigens. B cell contains two types of antigen-recognising molecules IgM and IgD. The variable region of IgM recognises the foreign antigen and IgD helps in the antigen interaction.

First the IgM is expressed on the surface of the B cells and then IgD is expressed on the surface and both jointly work in recognition of the foreign antigen. If the B cell receptor is devoid of IgD, IgM cannot alone cannot interact with the antigen because IgD provides stability to IgM.