Let b be an organism, and a ≺ b a subsystem of b, of kind [a]. Further, call π(a) the totality of processes or activities, involving a during a certain period. Then (i) any subset of π(a) that includes any of the processes listed in Postulate 3.1 is a biological function; (ii) the specific biological functions of a are those performed by a and its likes but not by any other subsystems of b.