Final answer:
Rolling circle replication is the process by which circular DNA, such as in E. coli and other bacteria, is duplicated, involving the nicking of one strand and unidirectional replication.
Step-by-step explanation:
The common type of replication that takes place in circular DNA such as that found in E coli and other bacteria is called rolling circle replication. This method allows the replication of circular DNA molecules like bacterial plasmids and certain bacteriophages. In this process, an enzyme creates a nick in one of the DNA strands of the circular molecule at the double-stranded origin. DNA polymerase III then utilizes the intact strand as a template to synthesize new DNA, while the nicked strand is displaced. Once replication is complete, the displaced strand can potentially recircularize to form a new DNA molecule. In bacteria, this mechanism is efficient and integral for replication of certain plasmids, bits of extrachromosomal DNA and is different from the typical binary fission process, which involves bidirectional replication starting from a single origin of replication in the bacterium's circular chromosome.