The bacterial cell's control system has a hierarchical organization. The signaling and the control subsystem interfaces with the environment by means of sensory modules largely located on the cell surface. The genetic network logic responds to signals received from the environment and from internal cell status sensors to adapt the cell to current conditions. A major function of the top level control is to ensure that the operations involved in the cell cycle occur in the proper temporal order. In "Caulobacter", this is accomplished by the genetic regulatory circuit composed of five master regulators and an associated phospho-signaling network. The phosphosignaling network monitors the state of progression of the cell cycle and plays an essential role in accomplishing asymmetric cell division. The cell cycle control system manages the time and place of the initiation of chromosome replication and cytokinesis as well as the development of polar organelles. Underlying all these operations are the mechanisms for production of protein and structural components and energy production. The “housekeeping” metabolic and catabolic subsystems provide the energy and the molecular raw materials for protein synthesis, cell wall construction and other operations of the cell. The housekeeping functions are coupled bidirectionally to the cell cycle control system. However, they can adapt, somewhat independently of the cell cycle control logic, to changing composition and levels of the available nutrient sources.