This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: DNB 2018, Subject name: Biochemistry
[{'content': 'Telomerase has action of: \nSelect and explain. \nA. DNA polymerase 1, B. DNA polymerase 2, C. DNA polymerase 3, D. Reverse transcriptase', 'role': 'user'}, {'content': 'Answer: D \nExplanation: Telomerase - Telomerase is a ribonucleoprotein paicle required for telomere maintenance. Telomerase contains an RNA that serves as the template, not the primer , for the synthesis of telomeric DNA by the reverse transcriptase of telomerase. Telomeric RNA has no catalytic activity. As a reverse transcriptase, telomerase synthesizes DNA using its RNA template and so is an RNA-transcriptase DNA polymerase. Telomerase is highly active in the early embryo, and after bih it is active in the reproductive and stem cell. Telomerase activity high in cancer cell.', 'role': 'assistant'}]