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': 'Function of mitochondrial DNA ? \nSelect and explain. \nA. Encodes proteins of cell membrane, B. Encodes proteins of respiratory chain, C. Helps in cell replication, D. Formation of rRNA', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Human mitochondria contain two to ten copies of a small circular double-stranded DNA molecule that makes up approximately 1% of total cellular DNA.The majority of the peptides in mitochondria (about 54 out of 67) are coded by nuclear genes.The rest are coded by genes found in mitochondrial (mt) DNAThis mtDNA codes for mt ribosomal and transfer RNAs and for 13 proteins that play key roles in the respiratory chain.', 'role': 'assistant'}]