What characterizes satellite viruses?

Satellite viruses are characterized by their dependency on other viruses for replication. This unique relationship sets them apart from typical viruses. Unlike standard viruses, which can often replicate on their own given the right conditions, satellite viruses lack the necessary genetic machinery to replicate independently. Instead, they rely on a helper virus to provide the essential proteins and components needed for their replication and assembly within a host cell.

In essence, satellite viruses cannot complete their life cycle without co-infection from a helper virus, which may provide the enzymatic functions or structural proteins that the satellite virus is missing. This is crucial for understanding their biological role, as they can manipulate their helper viruses to maximize replication and spread within a host, sometimes influencing the pathogenicity of the helper virus as well.