Question

QUESTION 39 The poly (A) tall on the mRNA of poliovirus is generated by which of the following mechanisms: A encoded in the genome B. a run of UUUUUUU causes the RNA-dependent RNA polymerase to stutter oc. added by the polyadenylation enzymes of the host cell D. stealing it from the host cell E poliovirus mRNAs do not have a poly (A) tail QUESTION 40 Eukaryotic ribosomes cannot translate polycistronic mRNAs. Poliovirus utilizes which of the following strategies to solve the polycistronic problem": A segmented genome OB. poliovirus mRNA is not polycistronic OC.multiple IRES D. protease cleavage of a polyprotein E. alternative splicing

Answer 1

39 ) a run of UUUUUUUU causes the RNA dependant RNA polymerase to stutter

RNA of many eukaryotic viruses, ranging from DNA to RNA viruses, have 3' poly(A) tails , which are synthesized not only post transcriptionally, but also by direct transcription from the poly(U) stretched template strand .

40 ) protease cleavage of polyprotein

The messenger (long chain) may later be cleaved into individual messages ( short chains ), each of which is translated into a single protein, or a giant polypeptide chain may be translated that is later cleaved to yield the individual proteins.