accelular microorganisms (viruses, viroid and prions)
Viruses are acellular microorganisms that exhibit characteristics distinct from other life forms. They are considerably smaller than bacteria and require a host to survive and replicate, possessing a single type of nucleic acid and a protein coat.
using International Commities for Taxonomy o virus(ICTV)
~ nucleic acid type
~ nucleic acid strandedness
~the sense (+ve/-ve) of ssRNA
~presence?absence of envelope
~type of host