Final answer:
In all cells except mature B-cells, the germline configuration of the Ig variable region genes is unrearranged. During the maturation of B-cells, DNA recombinase randomly excises V and J segments from the light chain gene, resulting in the production of unique variable chains capable of binding different antigens. This rearrangement process generates a vast diversity of antibody molecules.
Step-by-step explanation:
In all cells except mature B-cells, the germline configuration of the Ig variable region genes is unrearranged (b).
During the maturation of B-cells, an enzyme called DNA recombinase randomly excises V and J segments from the light chain gene. Through recombination and splicing, each differentiated B cell typically has a unique variable chain capable of binding a different antigen.
As a result, the gene segments encoding antibody polypeptides undergo rearrangement to produce an enormous diversity of antibody molecules that can recognize, bind, and eliminate invading antigens.