This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Replication, Subject name: Biochemistry
Telomerases are: 
Select and explain. 
A. DNA dependent DNA polymerase, B. RNA dependent DNA polymerase, C. DNA dependent RNA polymerase, D. RNA dependent RNA polymerase
B: RNA dependent DNA polymerase
Answer: B: RNA dependent DNA polymerase 
Explanation: Telomerases are RNA dependent DNA polymerase. Telomerase enzyme is present in germ cells and stem cells. And because of the presence of telomerase these cells have infinite number of divisions as compared to somatic cells. Telomerase prevent Telomere shoening. Telomerase activity increases in cancer. Telomerase activity decreases ageing.