This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Biochemistry
[{'content': 'Which of the organelles contain DNA? \nSelect and explain. \nA. Nucleus, B. Nucleolus, C. Golgi apparatus, D. Ribosomes', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Nucleus is the largest cellular organelle, surrounded by a double membrane nuclear envelope.\xa0\nThe outer membrane is continuous with the membranes of endoplasmic reticulum.\nAt certain intervals, the two nuclear membranes have nuclear pores with a diameter of about 90 nm.\xa0\nThese pores permit the free passage of the products synthesized in the nucleus into the surrounding cytoplasm.\nNucleus contains DNA, the repository of genetic information.\xa0\nEukaryotic DNA is associated with basic protein (histones) in the ratio of 1 : 1\xa0to form nucleosomes.\nAn assembly of nucleosomes constitutes chromatin fibres of chromosomes.\n\nKey Concept:\n\nNucleus contains DNA, the repository of genetic information.\xa0\nEukaryotic DNA is associated with basic protein (histones) in the ratio of 1 : 1, to form nucleosomes.\n\nRef: Textbook of Biochemistry, Satyanarayana', 'role': 'assistant'}]