Why is Foot-and-Mouth Disease considered a quasi-species?

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Multiple Choice

Why is Foot-and-Mouth Disease considered a quasi-species?

Quasi-species describes a population of related viral genomes that exists as a cloud of variants, not a single fixed sequence, because RNA viruses mutate rapidly during replication. Foot-and-Mouth Disease Virus is an RNA virus with an error-prone RNA-dependent RNA polymerase, so each replication cycle generates many mutations. This produces a diverse swarm of closely related genomes within an infected host, and natural selection acts on that swarm, allowing rapid adaptation to immune pressures and vaccines. That ongoing mutational diversity is exactly what the term quasi-species captures, making the statement that the virus continually mutates, producing variability the best description. It’s not a single stable serotype, since FMDV has multiple serotypes and extensive variation; it’s not a DNA genome, as it is RNA-based; and it does not infect only a single host species, since it affects several cloven-hoofed animals.

Quasi-species describes a population of related viral genomes that exists as a cloud of variants, not a single fixed sequence, because RNA viruses mutate rapidly during replication. Foot-and-Mouth Disease Virus is an RNA virus with an error-prone RNA-dependent RNA polymerase, so each replication cycle generates many mutations. This produces a diverse swarm of closely related genomes within an infected host, and natural selection acts on that swarm, allowing rapid adaptation to immune pressures and vaccines. That ongoing mutational diversity is exactly what the term quasi-species captures, making the statement that the virus continually mutates, producing variability the best description.

It’s not a single stable serotype, since FMDV has multiple serotypes and extensive variation; it’s not a DNA genome, as it is RNA-based; and it does not infect only a single host species, since it affects several cloven-hoofed animals.

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