Segmented RNA genomes: Reovirus vs. influenza virus — identify the correct pairing of segment number and nucleic acid type used in classical virology descriptions.

Introduction / Context:Segmented viral genomes allow genetic reassortment and rapid evolution. Two exam favorites are the Reoviridae (dsRNA) and Orthomyxoviridae (influenza, negative-sense ssRNA), each with characteristic segment counts.

Given Data / Assumptions:

• Reovirus: a prototypical dsRNA virus.
• Influenza virus: a negative-sense ssRNA virus.
• We compare segment numbers and nucleic acid types.

Concept / Approach:Classically, orthoreoviruses are described as having 10 dsRNA genome segments (partitioned into L, M, S classes). Influenza A/B viruses possess 8 separate segments of negative-sense ssRNA, each encoding one or more proteins. These canonical numbers are staples in virology curricula.

Step-by-Step Solution: Identify Reovirus genome: segmented dsRNA → 10 segments. Identify Influenza genome: segmented negative-sense ssRNA → 8 segments. Match the only option that pairs 10 dsRNA (reovirus) with 8 ssRNA (influenza). Select the correct pairing.

Verification / Alternative check:Reference virology handbooks list Reoviridae with 10 segments (orthoreoviruses) and influenza A/B with 8 segments; lab RT-PCR panels target these segment counts.

Why Other Options Are Wrong:

• 8/10, 5/7, 7/5: do not match standard segment counts and nucleic acid types for these viruses.

Common Pitfalls:Confusing reovirus with rotavirus (another reovirid) which commonly has 11 segments; the stem names reovirus generically and influenza, whose textbook numbers are 10 and 8 respectively.

Final Answer:10 different segments of dsRNA and 8 different segments of ssRNA respectively