Either, carbon, hydrogen, nitrogen, oxygen, phosphorus, or sulfur. I would go with carbon because of the photosynthesis and cellular respiration<span />
I am not sure how to answer
The answer is; Sodium (Na+) and Potassium (K+) Ions
These cations are pumped out of the cell by Na+-K+ transmembrane protein pumps leaving the inside of the cell electronegative in relation to the extracellular matrix. This membrane potential is significant especially for neurons. Depolarization of the membrane enables transmissions of an impulse along the neurons.
Commensalism is when one organism benefits off the other one without harming it. Examples are tree frogs that use plants for protection or jackals that have been expelled from packs trailing tigers and feeding on the remains of its kill. Barnacles on whales get shelter by attaching to a whales body