- Most DNA viruses are double-stranded (dsDNA), replicate in the nucleus (exception: Poxvirus), and have an icosahedral capsid (exception: Poxvirus).
- Most RNA viruses are single-stranded (ssRNA), replicate in the cytoplasm (exceptions: Orthomyxoviruses and Retroviruses), and are enveloped.
- Key Exceptions to Remember:
- DNA in Cytoplasm: Poxvirus
- RNA in Nucleus: Orthomyxovirus, Retrovirus
- Single-Stranded DNA: Parvovirus
- Double-Stranded RNA: Reovirus
- Segmented Genomes (BOAR): Bunyavirus, Orthomyxovirus, Arenavirus, Reovirus (important for genetic reassortment, e.g., influenza antigenic shift)