Here's why:
* DNA to RNA: The central dogma of molecular biology states that genetic information flows from DNA to RNA to protein. This means DNA is used as a template to create RNA (transcription).
* RNA to DNA: Reverse transcription is the exception to the central dogma. It is a process used by some viruses (like retroviruses, including HIV) to integrate their genetic material into the host's genome.
Therefore, reverse transcriptase is the enzyme that enables RNA to be used as a template for creating a DNA copy.