/At their most foundational level Living Things operate in either an open or a closed state. The closed state is discussed in the section on Protection. The open state, which is the default condition for the processes of life, is discussed here in this paper on Hunger and Thirst, which is the reflex to absorb nutrition. These reflexes are essential attributes of a functional Metabolic Core and enable Persistence.
/The other nutrient absorbing mechanism which we directly experience is:
Breathing