In an experimental situation, a student researcher inserts an mRNA molecule into a eukaryotic cells after she has removed the 5' cap and 3' poly A tail. Which of the following would you expect her to find? A. The mRNA attaches to a ribosome and is translated, but more slowly B. The cell adds a new poly-A tail to the mRNAC. The molecule is degraded rapidly because it is not protected at the ends D. The mRNA is quickly converted into a ribosomal subunit

Post-transcriptional modifications of primary transcripts in eukaryotes include the addition of 3' poly (A) tail, 5' cap to the transcript and removal of introns. The 5' cap is a residue of 7- methylguanosine that is linked to the 5' end of the mRNA. In addition to its role in the initiations of translation, the 5' cap protects mRNA against digestion from ribonucleases.

Eukaryotic mRNAs also have a string of 80 to 250 A residues called the poly (A) tail. This tail serves as a binding site for one or more specific proteins. The 3' poly (A) tail and the associated proteins are supposed to be involved in the protection of mRNA from enzymatic destruction. Since the inserted mRNA lacked 3' tail and 5' cap, it will be digested by one or other enzymes.