Final answer:
The typical peptide sequence recognized by a T-cell consists of about 8-10 amino acids.
Step-by-step explanation:
The typical peptide sequence recognized by a T-cell varies in length, but on average it consists of about 8-10 amino acids. These amino acids are part of the antigen-binding site of the T cell receptor. The antigen-binding site is formed by the terminal ends of both receptor chains, and the amino acid sequences of those areas combine to determine the receptor's specificity for a particular antigen.