<prompt> A Poly A base sequence would be most likely found at the5 end of a prokaryotic messenger RNA mRNA3 end of a prokaryotic mRNA5 end of a eukaryotic mRNA3 end of a eukaryotic mRNA  <response>: The addition of a poly A tail to the 3 end is one of the post-transcriptional modifications that occurs in the processing of eukaryotic messenger RNA mRNA. A cap consisting of a guanosine derivative is attached to the 5 end. Intervening sequences introns are removed by splicing. All of these processing events occur in the nucleus of eukaryotes. Prokaryotic mRNA undergoes none of these modifications. 