How do the peptide binding sites of MHC class 1 and class 2 molecules differ?

• A. MHC class 1 does not bind peptides, while MHC class 2 binds peptides of varying lengths.
• B. MHC class 1 binds longer peptides (12-20 amino acids), while MHC class 2 binds shorter peptides (8-10 amino acids).
• C. Both MHC class 1 and class 2 bind peptides of the same length (8-10 amino acids).
• D. MHC class 1 binds shorter peptides (8-10 amino acids), while MHC class 2 binds longer peptides (12-20 amino acids).

Answer: (D)