The viruses which are usually helped or accompanied by smaller spherical particles of another serologically unrelated virus known as

The viruses are usually helped or accompanied by smaller spherical particles of another serologically unrelated virus known as the Satellite virus.
A satellite is a subviral agent that depends on the coinfection of a host cell with a helper virus for its replication.
They encode structural proteins to enclose their genetic material, which is therefore distinct from the structural proteins of their helper viruses.
Satellites are completely dependent on a helper virus for replication. The symbiotic relationship between a satellite and a helper virus catalyzes the replication of a satellite genome.