What do all complex multicellular organisms have in common? a means by which to hold cells together regulatory gene networks that control cell and tissue differentiation patterns simple patterns of cell and tissue differentiation highly developed cell-cell communication

Answer: the correct option is : highly developed cell - cell communication.

Explanation: In complex multicellular organisms, cell - cell communication also known as cell signalling is part of any communication process that leads basic activities of cells and coordinates multiple cell functions.