Question: who concluded that all cells came from existing cells
[{'answer': 'Rudolf Virchow', 'provenance': [{'wikipedia_id': '102858', 'title': 'Cell theory', 'start_paragraph_id': 1, 'start_character': 954, 'end_paragraph_id': 1, 'end_character': 968, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}, {'provenance': [{'wikipedia_id': '102858', 'title': 'Cell theory', 'start_paragraph_id': 21, 'start_character': 0, 'end_paragraph_id': 21, 'end_character': 280, 'bleu_score': 0.9560167778278961, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 4467293681306960419}, 'section': 'Section::::Cell theory.\n'}]}]