what kind of gas is inside the bubbles?; fermentation is cellular respiration without which molecule?; how does the rate of photosynthesis change when the light source is turned on?; what is the reaction in photosynthesis that produces the bubbles; what energy source is used by elodea; how does the process of photosynthesis in plants provide energy for animals?; what products of cellular respiration are necessary for photosynthesis to occur?; find the average number of bubbles at each distance from the light source. show your work.