Plasmid DNA is naked double stranded DNA that forms a circle with no free ends. It is associated with few protein but contains RNA polymerase enzyme. They are smaller than the host chromosome and can be easily separated. Chromosomal DNA is double stranded linear DNA molecular associated with large proteins. This DNA exists in relaxed and supercoiled and provides a template for replication and transcription. It has free ends represented as 3′−5′3′−5′.