Genome in virion RNA RNA一DN Viruses viruses vIruses SS DNA ds dNA SS RNA ds Rna SS RNA ds rna (Retroviruses Hepadnaviruses) Viral genomes. The genomes of viruses can be composed of either DNa or rna, and some use both as their genomic material at different stages in their life cycle However, only one type of nucleic acid is found in the virion of any particular type of virus. This can be single stranded(ss), double-stranded(ds), or in the case of the hepadnaviruses, partially double-strandedGenome in virion Viral genomes. The genomes of viruses can be composed of either DNA or RNA, and some use both as their genomic material at different stages in their life cycle. However , only one type of nucleic acid is found in the virion of any particular type of virus. This can be single￾stranded (ss), double-stranded (ds), or in the case of the hepadnaviruses, partially double-stranded