Final answer:
Recombination signal sequences (RSSs) guide the rearrangement of V, D, and J segments during the development of the immune system's diverse repertoire of antibodies and T-cell receptors.
Step-by-step explanation:
The rearrangement of V (variable), D (diversity), and J (joining) segments in the immune system is guided by flanking DNA sequences called recombination signal sequences (RSSs). These sequences are essential for the mechanism of V(D)J recombination, which is pivotal in the development of a diverse repertoire of immunoglobulins and T-cell receptors (TCRs), providing specific immune responses to an array of antigens. RSSs direct an enzyme called DNA recombinase, which facilitates the excision and joining of these gene segments, thereby contributing to the immense diversity of the immune system.