Question: when would the quantity of dna double when growing cells
[{'answer': 'S phase', 'provenance': [{'wikipedia_id': '564779', 'title': 'Cell growth', 'start_paragraph_id': 1, 'start_character': 316, 'end_paragraph_id': 1, 'end_character': 323, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}]