It is during the phase cytokinesis that the cell membrane separates the cell into two.
It is true, it does release hydrogen ions in a water base.
The barnacles are only able to attach them selfs to surfaces in the water. Since the surface is limited, barnacles are attaching themselves to the other barnacles, crowding the rock. The muscles were not able to grow or attach themselves off the surface of the rock. Same thing with the mussels that are growing on the rock. So not only barnacles are crowding the rock, but Mussels as well are crowding the rock.
Explanation:
In all living system we can always find basic elements carbon, oxygen, nitrogen and hydrogen, carbon is the basic building unit contained in living matter. The percentage of carbon in the mass of living matter is 19.0% oxygen and hydrogen are present in almost all organic compound which creates living organisms.
Your answer is "tiny structures in the cell that carry out the activities."