A retrovirus has a genome that consists of __________.

• A. double-stranded DNA
• B. single-stranded RNA
• C. double-stranded RNA
• D. single-stranded DNA

Answer: (B)

Verified step by step guidance

1. Understand the nature of retroviruses: Retroviruses are a group of RNA viruses that have the unique ability to reverse transcribe their RNA genome into DNA after infecting a host cell.
2. Recall the genetic material of retroviruses: Unlike many viruses that carry DNA or double-stranded RNA, retroviruses carry their genetic information as single-stranded RNA (ssRNA).
3. Recognize the role of reverse transcriptase: Retroviruses use an enzyme called reverse transcriptase to convert their single-stranded RNA genome into double-stranded DNA once inside the host cell.
4. Differentiate from other virus types: Double-stranded DNA viruses have DNA genomes, and double-stranded RNA viruses have RNA genomes, but retroviruses specifically have single-stranded RNA genomes.
5. Conclude that the genome of a retrovirus consists of single-stranded RNA based on its replication mechanism and classification.