The folded chromosome in cells. The bacterial chromosomes are compactly organized into complex structures. (A) The chromosomal structures of E. coli are different in the exponential growth phase and the stationary phase. (B) The bacterial chromosome is organized at different scales. The operons/TUs along the genome will form DNA loops and large chromosome substructures (i.e. CIDs). Further, independently organized domains (MDs) can be observed.