vary in size depending on species but often has a folded structure to form a dense body which is visible using a scanning electron microscope. During replication the DNA helix unwinds and both daughter cells (produced by binary fission) receive | vary in size depending on species but often has a folded structure to form a dense body which is visible using a scanning electron microscope. During replication the DNA helix unwinds and both daughter cells (produced by binary fission) receive |