<prompt> Poly A tail of m-RNA translates into which of the following polypeptides?PolyglycinePolylysinePolyalaninePolyproline  <response>: Ans. b. Polylysine Ref: Harper 28e p362, 27e p366; Lippincotts 4e p432, 424-27Poly A tail of m-RNA translates into Polylysine.CodonAAAGGGCCCTTTUUUTranslation productLysinQGlycineProlinePhenylalanine Poly A tail is translated into the polylysine tail as AAA is the codon for lysine amino acid. Messenger RNAs, particularly in eukaryotes, have some unique chemical characteristics. The 5 terminal of mRNA is capped by a 7-methylguanosine triphosphate. The cap is involved in the recognition of mRNA by the translating machinery, and it probably helps stabilize the mRNA by preventing the attack of 5 -exonucleases. At their 3 end, most eukaryotic mRNAs have a suing of 80 to 250 adenylate residues, making up the poly A tail. The poly A tail and its associated proteins help protect mRNA from enzymatic destruction. 