Virus classification Flashcards
what are the two Virus classifications
- classical
2. baltimore
how does the classical classification system distinguish viruses.
viruses are grouped together based on their physical properties rather than their hosts
what are the 4 common factors examined in classical classification?
- DNA vs RNA (nature of genetic material in virion)
- Helical or icosahedral (capsid symmetry)
- Naked vs. enveloped
- dimensions of the virion and capsid
explain the baltimore classification of viruses
based on the central dogma of the genome. All viruses must make mRNA that then encodes for a protein. Baltimore classification classifies viruses on the pathway they use to go from thier viral genome to mRNA.
Baltimore pathway one = herpesvirus
(+/-) dsDNA –> +mRNA
Baltimore pathway two = parovirus
+DNA –> dsDNA –> +mRNA
Baltimore pathway three = Reovirus
+/- RNA (dsRNA) –> +mRNA
baltimore pathway 4 = picornavirus
+RNA –> -RNA –> +mRNA
baltimore pathway 5 = orthomyxovirus
-RNA –> + mRNA
baltimore pathway 6: retrovirus
+RNA –> -DNA –> dsDNA –> +mRNA