Most biological entities that are more complex than a virus sometimes or always carry additional genetic material besides that which resides in their chromosomes. In some contexts, such as sequencing the genome of a pathogenic microbe, "genome" is meant to include information stored on this auxiliary material, which is carried in <answer>plasmids</answer>. In such circumstances then, "genome" describes all of the genes and information on non-coding DNA that have the potential to be present.
Where is additional genetic material found in pathogenic microbes?
plasmids