In QB replicase, what is the primary target for amplification?

The primary target for amplification in QB replicase is RNA only. QB replicase is an enzyme that specifically facilitates the replication of RNA viruses, particularly the RNA component of the bacteriophage QB. This enzyme synthesizes complementary RNA strands using an RNA template.

In the context of the choices, it is important to note that replicase is designed to work with RNA substrates, which means it efficiently amplifies RNA sequences rather than DNA. While it is primarily associated with RNA amplification, during various experimental setups, RNA can be transcribed from DNA templates through reverse transcription processes, but QB replicase itself does not amplify DNA directly. Protein molecules do not serve as templates for replicase activity, as they are end products of RNA translation, further affirming that the enzyme’s function is not related to protein amplification.

Thus, focusing on the specific role of QB replicase confirms that it targets and amplifies RNA, making it evident that the answer pertains explicitly to RNA.