Final answer:
The antigen receptors on T cells are part of the same protein family as antibodies, a fact that is true. TCRs have both variable and constant regions similar to antibodies but are structurally simpler with just two peptide chains.
Step-by-step explanation:
The antigen receptors on T cells indeed come from the same family of proteins as antibodies. This statement is true. Similar to antibodies, the T cell receptor (TCR) comprises a variable region and a constant region. The variable region is responsible for binding to the antigen. Although they share structural similarities, the TCR is less complex than antibodies, having only two peptide chains (α and β chains) compared to the four peptide chains and Y-shaped structure of antibodies. It's important to note that the TCR does not function independently but in conjunction with Major Histocompatibility Complex (MHC) molecules to recognize antigens.