<prompt> Quaternary structure of protein is:The arrangement sequence of amino acids in the polypeptide chainInter relation between amino acids in a single polypeptide chainInter relation of amino acid in 2 polypeptide chainsThe inter relation and arrangement of polypeptides in a protein with more than 2 polypeptides chains  <response>: Ans. D. The inter relation and arrangement of a polypeptides in the protein with more than 2 polypeptides chainsa. Protein that contain two or more polypeptide chains associated by non-covalent forces are said tob. exhibit quaternary structure.c. The arrangement sequence of amino-acids in the polypeptide chain -- is primary structure of protein.d. Inter relation of amino-acids in polypeptide chain is -- secondary structure. 