Virus Classification

Viruses do not share the same classification system as organisms because they are not considered to be living

  • Viruses do not have metabolism and can only reproduce using the cellular machinery of an infected host cell

Viruses are classified mainly according to phenotypic characteristics, including:

  • Morphology (e.g. helical, icosohedral, spherical, complex)
  • Nucleic acid type (e.g. DNA = adenovirus ; RNA = retrovirus)
  • Method of viral replication (e.g. lytic vs lysogenic cycles)
  • Host organisms (e.g. bacteriophages)
  • Types of disease caused (e.g. influenza virus, HIV)

Types of Viruses

types of viruses