__________ is an enzyme that may have evolved from ancient progenitor cells with an RNA genome. It functions as a __________.

Question

Quizplus · Accepted Answer

Telomerase is an enzyme that adds repetitive nucleotide sequences to the ends of chromosomes (telomeres) in order to prevent their shortening during DNA replication. Studies suggest that telomerase may have evolved from ancient RNA viruses, which had reverse transcriptase activity, and that telomerase itself has reverse transcriptase activity. Hence, the correct option is (D) Telomerase; reverse transcriptase. The other options are incorrect because primase is an enzyme that synthesizes RNA primers during DNA replication, helicase is an enzyme that unwinds DNA duplexes during replication and transcription, and methylator and acetylator are enzymes that add methyl and acetate groups, respectively, to nucleotides and histones.

__________ Is an Enzyme That May Have Evolved from Ancient