Final answer:
The composition of dodecapeptide X based on the amino acid analysis is 4 ala, 2 gln, 2 met, and 2 phe, which corresponds to Option 1.
Step-by-step explanation:
The primary structure of proteins is the linear sequence of amino acids as they are connected by peptide bonds in a polypeptide chain, going from the N-terminus to the C-terminus. The dodecapeptide in question is composed of 12 amino acids. Given the amino acid analysis showing 4ala, 2gln, 2met, 2phe, the composition reflects the number of each amino acid present in the peptide. Therefore, the correct composition of the dodecapeptide X is Option 1: 4ala, 2gln, 2met, 2phe.