Chemical Composition and Mode of Replication: The genome of a virus may consist of DNA or RNA, which may be single stranded (ss) or double stranded (ds), linear or circular. The entire genome may occupy either one nucleic acid molecule (monopartite genome) or several nucleic acid segments (multipartite genome).
In what forms do we find the viral genome?
Viral genomes can be found as single or double-stranded versions of DNA and RNA, packaged in segments or as one piece, and present in both linear and circular forms.
What are the major types of viral genomes?
RNA viral genomes are broadly divided into double stranded RNA, positive and negative strand single stranded RNAs, monopartite and multipartite RNA viruses. One of the primary proteins encoded by all these RNA genomes is RNA dependent RNA polymerase, essential for their replication.
What are the three main virus groups?
- Viruses are classified into four groups based on shape: filamentous, isometric (or icosahedral), enveloped, and head and tail.
- Many viruses attach to their host cells to facilitate penetration of the cell membrane, allowing their replication inside the cell.
What is the largest virus?
Mimivirus is the largest and most complex virus known.
Why are viruses considered non living?
Viruses are not living things. Viruses are complicated assemblies of molecules, including proteins, nucleic acids, lipids, and carbohydrates, but on their own they can do nothing until they enter a living cell. Without cells, viruses would not be able to multiply. Therefore, viruses are not living things.