9.1.1 Types of Viral Genomes The genomes of viruses: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). 因组可以是DNA或RNA,可以是单链或双链，但毒粒中只能存在一种核酸 RNA DNA Viral Class DNA viruses RNA viruses viruses Viral Genome SsDNA dsDNA SsRNA SsRNA dsDNA dsRNA (Retroviruses) (Hepadnaviruses) 2012 Pearson Education.Inc. Retroviruses反转录病毒： contain an RNA genome in the Hepatitis B virus乙肝病毒： virion but replicate through a contains partially ds DNA in the DNA intermediate. virion but has an RNA intermediate in replication9.1.1 Types of Viral Genomes The genomes of viruses: 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). 病毒基 因组可以是DNA或RNA, 可以是单链或双链, 但毒粒中只能存在一种核酸. Retroviruses 反转录病毒: contain an RNA genome in the virion but replicate through a DNA intermediate. Hepatitis B virus乙肝病毒: contains partially ds DNA in the virion but has an RNA intermediate in replication