Virus classification Guide, Meaning , Facts, Information and Description
Viruses can be classified in several ways, such as by their geometry, by whether they have envelopes, by the identity of the host organism they can infect, by mode of transmission, or by the type of disease they cause. The most useful classification is probably by the type of nucleic acid the virus contains and its mode of expression. This classification was proposed by Nobel-prize winner David Baltimore. It should be noted that none of these classifications are expected to be phylogenetic, as viruses may not share a common origin.
Overview
The various forms of viruses arise because one of the two strands of DNA in which all cellular life forms store their genetic information is redundant, so that viruses can have either single-stranded or double-stranded genomes. Furthermore, some viruses store their genome in RNA rather than in DNA form. RNA arises in cells as an intermediate when genes are translated into proteins. RNA genomes of viruses can be encoded in two different directions: Either the genes are stored in the 5'->3' direction (positive or + polarity), analogous to the direction in which genes are represented in mRNA in cells, or the genes are stored in the opposite direction (negative or - polarity).
The taxonomy of viruses is similar to that of all other forms of life:
- Class (determined by genome type and mode of expression)
This is an Article on Virus classification. Page Contains Information, Facts Details or Explanation Guide About Virus classification Classification by genome type
DNA viruses
dsDNA viruses (double stranded DNA)
ssDNA viruses (single stranded DNA)
RNA viruses
dsRNA viruses (double stranded RNA)
(+)ssRNA viruses (positive single stranded RNA)
(-)ssRNA viruses (negative single-stranded RNA)
Naked RNA viruses
DNA and RNA Reverse Transcribing viruses
ssRNA-RT viruses (single stranded RNA)
dsDNA-RT viruses (double stranded DNA)
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