This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Metabolism of nucleic acids, Subject name: Biochemistry
Telomerase is 
Select and explain. 
A. DNA dependent RNA polymerase, B. RNA dependent DNA polymerase, C. RNA dependent RNA polymerase, D. DNA dependent DNA polymerase
B: RNA dependent DNA polymerase
Answer: B: RNA dependent DNA polymerase 
Explanation: The replication always takes place from 5' to 3' direction in the new strand.The DNA polymerase enzyme is not able to synthesize the new strand at the 5 ' end of the ne2 strand. This end piece of the chromosome is called telomere.Therefore another enzyme , telomere terminal transferase or telomerase takes up this job of replication of the end piece of chromosomes.. The shoening of telomere end is prevented by an enzyme telomerase.It contains an RNA component, which provides the template for telomeric repeat synthesis. REFERENCE DM.VASUDEVAN.TEXTBOOK SEVENTH EDITION ; PAGE NO : 585.