A chromosome is an 'X' shaped gene which contains DNA, found inside living cells. Chromosomes are easily seen using a microscope and are normally invisible most of the time (tâ¦his period of time called 'interphase') but become visible when the cell starts to multiply.
Bacterial DNA â a circular chromosome plus plasmids. The DNA of most bacteria is contained in a single circular molecule, called the bacterial chromosome. The chromosome, along with several proteins and RNA molecules, forms an irregularly shaped structure called the nucleoid.This sits in the cytoplasm of the bacterial cell.In addition to the chromosome, bacteria often contain plasmids â small circular DNA molecules. Bacteria can pick up new plasmids from other bacterial cells (during conjugation) or from the environment.his sits in the cytoplasm of the bacterial cell. In addition to the chromosome, bacteria often contain plasmids â small circular DNA molecules. Bacteria can pick up new plasmids from other bacterial cells (during conjugation) or from the environment.
Many bacteria, including E. coli, contain plasmids that each contain an origin of replication. These are separate from the origins of replication that are used by the bacteria to copy their genome and often function very differently.he genome of E. coli consists of a single circular DNA molecule of approximately 4.6 x 10 6 nucleotide pairs. DNA replication typically begins at a single origin of replication.