<P> Virus classification is the process of naming viruses and placing them into a taxonomic system . Similar to the classification systems used for cellular organisms, virus classification is the subject of ongoing debate and proposals . This is mainly due to the pseudo-living nature of viruses, which is to say they are non-living particles with some chemical characteristics similar to those of life . As such, they do not fit neatly into the established biological classification system in place for cellular organisms . </P> <P> Viruses are mainly classified by phenotypic characteristics, such as morphology, nucleic acid type, mode of replication, host organisms, and the type of disease they cause . Currently, two main schemes are used for the classification of viruses: the International Committee on Taxonomy of Viruses (ICTV) system and Baltimore classification system, which places viruses into one of seven groups . Accompanying this broad method of classification are specific naming conventions and further classification guidelines set out by the ICTV . </P>

Where do viruses fit in the current classification system and why