<prompt> Biological value of a protein is related toNitrogen contentamino acid contentSulphur contentEnergy content  <response>: Ans a Nitrogen content Ref paik 20th ed p 549Biological value of a protein is Retained N2 Absorbed N2 x 100Protein efficiency ratio Wt gain in gms Gram of protein consumedNet protein utilization Digestibility Coefficent x Biological value100 Aminoacid score No of mg of one AAgm of proteinNo of mg of same AAgm of egg proteinx 100Quality of protein is assessed by comparison to the reference protein which is usually egg protein. 