7. Molecular formal inversion - B.

Viruses. In the virus called phage Mu, in addition to the Fundamental Formal Inversion, there are also further DNA inversions that provide it with flexible function in the interests of survival. For example, it has an invertible sequence of 3,000 base pairs called the G segment. Depending on whether the segment is in its G+ or G- orientation, the virus can attack B. coli or other host cells. Thus formal inversion was apparently an already well established principle in the molecular brain-mind homologues of viruses.