Gene expression might be altered at the level of post-transcriptional processing in eukaryotes rather than prokaryotes because of which of the following? a. eukaryotic mrnas get 5' caps and 3' tails. b.prokaryotic genes are expressed as mrna, which is more stable in the cell. c.eukaryotic exons may be spliced in alternative patterns. d.prokaryotes use ribosomes of different structure and size. e.eukaryotic coded polypeptides often require cleaving of signal sequences before localization