Final answer:
The second type of TCR consists of the gamma and delta chains, which undergo genetic rearrangement to form a specific antigen-binding site and contribute to the immune system's ability to recognize a diverse range of antigens.
Step-by-step explanation:
The secondary type of T Cell Receptor (TCR) is formed by the TCR gamma chain and TCR delta chain, differing from the more common alpha-beta TCR which is formed by alpha (a) and beta (ß) chains. Like alpha-beta TCRs, gamma-delta TCRs recognize antigens, but they do so through a distinct arrangement of variable (V), diversity (D), and joining (J) gene segments. These segments undergo genetic rearrangement to provide a unique variable region that determines the antigen specificity of the TCR.
This means each TCR can bind to a particular antigen, allowing the immune system to respond to a vast array of pathogenic challenges.