Question: where does mrna processing take place in eurkaryotic cells
[{'answer': 'nucleus', 'provenance': [{'wikipedia_id': '9955145', 'title': 'Eukaryotic transcription', 'start_paragraph_id': 1, 'start_character': 481, 'end_paragraph_id': 1, 'end_character': 488, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}]