Which of the following steps in preparation of a fully mature eukaryotic mRNA occurs within the nucleus?

a. Transcription

b. Capping

c. splicing

d. Polyadenylation

e. All of the above

Answer: e. All of the above

Explanation:

The processing of mRNA to a fully mature eukaryotic mRNA requires addition of a 5' cap (Capping) and 3' poly (A) tail (polyadenylation) to the ends of the transcript, and removal of any intervening introns by splicing. Once processing is completed, the mRNP, which consists of mRNA and associated proteins, is ready for export from the nucleus.