Binary Fission Cell wall Plasma membrane Cell elongates and DNA is replicated DNA(nuclear area) 2 Cell wall and plasma membrane begin to divide DNA Partially Cell wall (nuclear formed area) cross-wall 3 Cross-wall forms completely around divided DNA Cells separate (a)A diagram of the sequence (b)A thin section of a cell of Bacillus of cell division. licheniformis starting to divide. Figure 6.11 Binary Fission Figure 6.11