This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Immunology, Subject name: Microbiology
Structure of antibodies is composed of - 
Select and explain. 
A. Single peptide chain, B. Two peptide chain, C. Non sulphur amino acid, D. 2 long and 2 sho peptide chains
D: 2 long and 2 sho peptide chains
Answer: D: 2 long and 2 sho peptide chains 
Explanation: Antibody or immunoglobulin are glycoproteins molecules consisting of four polypeptide chains. - two identical heavy chains ( H) , molecular weight > 50 kDa. - two identical light chains (L), molecular weight > 25kDa. - the heavy chains are of five types called alpha, gamma, delta , epsilon and mu. - light chains are similar in all class of immunoglobulins. Reference : Anathanarayan & paniker's 9th edition, pg no: 94 <\p>