Immunoglobulin, TCR, and MHC proteins share structural features and have evolved by duplication and selection of primordial antigen receptors.

A. True.

B. False

True.

Explanation:

The immunoglobulins, MHC (major histocompatibity complex) and TCR (T cell receptor) plays an important role in the immune system. They protect the individual from the harmful antigens.

The evolution of immune system has done the duplication process. The genes gets duplicated and evolved to perform the specific function. The Immunoglobulin, TCR, and MHC gene evolve by the process of duplication. These genes mainly acts against the specific pathogen and shows the selection according to the primordial antigen receptors.

Thus, the answer is true.