<P> I: dsDNA viruses II: ssDNA viruses III: dsRNA viruses IV: (+) ssRNA viruses V: (-) ssRNA viruses VI: ssRNA - RT viruses VII: dsDNA - RT viruses </P> <Tr> <Td> Virus Glossary (hide) Virion (hide) <P> A single, fully functional virus particle outside its host cell </P> Capsid (show) The protein shell surrounding the virus's genes; this shell is made from many smaller proteins which are identical and are called capsomers . Envelope (show) <P> Some viruses have a bubble of fat that surrounds the virion . </P> Gene (show) <P> A segment of DNA or RNA; genes are like sentences made of the "letters" of the nucleotide alphabet . Genes direct the reproduction of viruses . Different types of viruses have genes made from DNA or RNA but not both . </P> Host range (show) <P> The animals, plants or bacteria that any one type of virus can infect . </P> Bacteriophages (show) <P> The viruses that reproduce in bacteria </P> Cell tropism (show) The type of cell in which a virus can reproduce Serotype (show) <P> A grouping of viruses based on the antigens on the surface of virus </P> Symmetry (show) <P> All viruses of a type are identical and their particles have a cubical, helical or complex structure . </P> <Ul> <Li> view </Li> <Li> talk </Li> <Li> </Li> </Ul> </Td> </Tr> <P> A single, fully functional virus particle outside its host cell </P> <P> Some viruses have a bubble of fat that surrounds the virion . </P>

Name one organelle due to lack of which virus are dependent on a living cell