Mr. Miller's biology class is studying cellular respiration. To model cellular respiration, they set up an experiment containing four flasks. Each flask is the same size and are stoppered and placed under a floodlight. Each flask also contains 200 mL of H₂O and 2 mL of bromothymol blue. Bromothymol blue is a chemical indicator solution that changes color from blue to yellow in the presence of CO₂.
Which flask(s) will turn yellow and why?
A) Flask 1 & 3 because these flasks contain plants that undergo photosynthesis.
B) Flask 3 (only) because this is the only flask in which photosynthesis and cellular respiration are both taking place.
C) Flask 1 & 2 because there is only one process taking place in each of these flasks so the products do not get used up.
D) Flask 2 (only) because the fish produce CO₂ as products of cellular respiration and do not undergo photosynthesis therefore not consuming CO₂.