Mitosis refers to nuclear division, which happens to coincide with cytokinesis. Prokaryotes do not have nuclei, therefore they do not undergo a process of mitosis. Instead, prokaryotes undergo the process of binary fission. Growth of new membranes during the cellular growth and expansion in a prokaryote occurs by 2 mechanisms 1) along the center of the cell or 2) apically. The chromosome of prokaryotes is organized in a circular form. A mechanism called the rolling circle model describes the replication of the chromosome that accompanies binary fission. This is also the mechanism utilized by extrachromosomal DNA called plasmids.