Telomerase has action of:

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.