Which organism is known for its unique genome structure, consisting of a linear chromosome and plasmids?

The organism known for its unique genome structure that includes a linear chromosome and plasmids is Borrelia burgdorferi. This bacterium is the causative agent of Lyme disease and is known for its distinctive genetic makeup. Unlike most bacteria, which typically have circular DNA, Borrelia burgdorferi has a linear chromosome, which is a notable exception in bacterial genetics. Additionally, it possesses plasmids that carry genes important for its survival and pathogenicity.

The presence of these plasmids allows Borrelia burgdorferi to adapt to different environments and evade the host immune response, contributing to its virulence. This genomic structure is a critical aspect of its biology and helps differentiate it from other bacterial species that do not have a similar arrangement of their genetic material.

In contrast, the other organisms listed typically have circular chromosomes and do not exhibit the same unique genomic characteristics as Borrelia burgdorferi.