Binary fission is simple ad rapid compared to mitosis that involves complexities like breaking down the nuclear membrane – which prokaryotes do not have – and replicating the many chromosomes – when prokaryotes have only one.
Replication of the circular DNA in prokaryotes happens as the process of division of the cell happens. In mitosis, the replication of all the genetic material must finish before the process of cytokinesis begins.
Spindle fibers are not formed in binary fission while they are significant in mitosis in drawing different chromosomes to different poles of the cell before cytokinesis.
