nomenclature. The Internationals Committee on Taxonomy of Viruses will keep track of these things in viruses. All recommendations are disseminated to the scientific community at large. Viruses can be classified in different ways, including their genome types, the viral capsid structure, whether there is an envelope of not, the host range, the pathogenicity of the virus, the similarity in gene sequences, and the range of host. There are certain orders, families, genuses, and species that get clustered together. For example, all viruses of the Picornavirales order have no envelopes, have icosahedral structures, and have a genome with positive-sense RNA. There are many families and genuses under these categories. Once you get to the genus level, the viruses in the same genus are the most similar to one another.
VIRUS LIFE CYCLES Viruses in general have roughly the same life cycle although, with bacteriophages, there are both lytic and lysogenic cycles to consider. The basic driving force behind all viral infections and their ability to succeed as pathogens is to have attachment to the right host, the proper metabolic pathways to make new virus particles, and the ability to release those particles in ways that affect another host cell. They do not go through division but instead undergo replication. Figure 6 shows the typical viral life cycle:
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