The cytoplasm in a single celled organism and the circulatory system in a human both?

What goes in and out of a cell respiration?

What gases are carried by the blood

Dr. arenas is a scientist who has been trying to determine if increasing pressure will increase the sound that occurs when two chemicals explode. it measures the volume of the sound that occurs at the minimum pressure at which the explosion will occur. it then increases the pressure and measures the volume of the explosions that occur. what kind of investigation is the scientist conducting?