Which statement below is a correct comparison of a "regular" RNA virus and an RNA retrovirus?

• A. Only the regular RNA virus performs transcription.
• B. Only the RNA retrovirus performs translation.
• C. Only the regular RNA virus produces DNA from an RNA template.
• D. Only RNA retroviruses produce DNA using DNA replicase.
• E. Both produce protein coats via translation of mRNA.

Answer: (E)

Verified step by step guidance

1. Understand the basic life cycle of a regular RNA virus: Regular RNA viruses typically have their genetic material in the form of RNA. Upon entering a host cell, their RNA is directly used as mRNA or transcribed into mRNA, which is then translated into viral proteins by the host's ribosomes.
2. Understand the basic life cycle of an RNA retrovirus: RNA retroviruses, such as HIV, have RNA as their genetic material but use a unique enzyme called reverse transcriptase to convert their RNA into DNA. This DNA is then integrated into the host's genome, where it can be transcribed into mRNA and translated into proteins.
3. Compare transcription processes: Both regular RNA viruses and RNA retroviruses involve transcription, but in different contexts. Regular RNA viruses may directly use their RNA as mRNA, while retroviruses transcribe their integrated DNA into mRNA.
4. Compare translation processes: Both types of viruses rely on the host cell's machinery to translate mRNA into proteins. This is a common step in the production of viral proteins, including protein coats.
5. Clarify the role of reverse transcriptase: Only RNA retroviruses use reverse transcriptase to produce DNA from an RNA template. Regular RNA viruses do not perform this step, as they do not integrate into the host genome.