Final answer:
The recombination of V, D, and J segments gives rise to the variable region of the heavy chain of an antibody, enabling a diverse array of antigen specificity.
Step-by-step explanation:
Recombination of a V (variable), a D (diversity), and a J (joining) segment give rise to the variable region of the heavy chain of an antibody. This genetic recombination contributes to the generation of a vast repertoire of antibodies, each with a unique antigen-binding site, facilitating the immune system’s ability to recognize an extraordinarily wide array of antigens. The process involves DNA recombinase mediating the splicing of these gene segments in B cells. Once V, D, and J segments are recombined, the resulting variable region can produce multiple antibody molecules that have the capacity to bind different antigens. Moreover, the complementarity-determining regions (CDRs), which are part of the variable domain, are crucial for the specific antigen recognition.