viruses

Virus contain contain single type of nucleic acid ,either DNA or RNA. Characteristic of virus can be divide into host range, nucleic acid,capsid and envelope, tail and type of diseases.

1)host range

Host range is determined by attachment site on the host and availability in the potential host the factors for viral replication .  location of attachment site is in the cell wall,fimbrie, and plasma membrane of animal cells. The host range of the virus will depend upon the presence of the receptors. If a host lacks the receptor for a virus, or if the host cell lacks some component necessary for the replication of a virus, the host will inherently be resistant to that virus.

2)nucleic acid

It have either DNA or RNA, circular or linear and can appear ingly or in several segments.

3)capsid and envelope

the capsid is surrounded by lipid bilayer that contains viral proteins that enable the virus to bind to the host cells. virus envelope is derived from the host cell membranes. The capsid and envelope play many roles in viral infection, including virus attachment to cells, entry into cells, release of the capsid contents into the cells, and packaging of newly formed viral particles. The capsid and envelope are also responsible for transfer of the viral genetic material from one cell to another. 

General morphology of virus is helical viruses,polyhedral viruses, enveloped viruses and complex viruses.

4) tail and type of disease

Virus is with tail or without tail that is use for attachment.