Question

two biology students, noah and mateo, conducted an experiment testing the effects of intense light vs darkness on the amount of dissolved oxygen in an aquatic ecosystem. they placed two aquatic plants (java moss) in a tank filled with freshwater. they exposed the tank to each condition for 30 minutes, and recorded the percent dissolved oxygen using a sensor. before each experiment, they allowed the tank to sit undisturbed in normal conditions for 6 hours. a graph of their data is shown below. unfortunately, the students forgot to label their data files, so they dont know which plant was exposed to which condition. noah claims the \a\ trial was exposed to the intense light, while mateo thinks \a\ was in the darkness. which students claim and reasoning is correct? mateo is correct. plants store light to photosynthesize; in the dark, oxygen use would increase. mateo is incorrect. plants substitute oxygen for energy in the dark; this would decrease the oxygen in the water. noah is correct. oxygen is a product of photosynthesis; intense light would increase the amount of oxygen in the water. noah is incorrect. plants use oxygen during photosynthesis; intense light would decrease the amount of oxygen in the water.

Explanation:

Plants perform photosynthesis in the presence of light, and oxygen is a product of photosynthesis. If a plant is exposed to intense light, more photosynthesis occurs, leading to an increase in dissolved oxygen. Noah's claim that "A" was exposed to intense light aligns with the fact that oxygen is a photosynthesis product and intense light would increase oxygen (assuming the graph for "A" shows an increase, which is logical as per photosynthesis - oxygen relationship). Mateo's idea about darkness (where photosynthesis doesn't occur at a significant rate compared to light - dependent photosynthesis) is incorrect in the context of oxygen production. Also, plants use carbon dioxide and water (with light) to produce glucose and oxygen in photosynthesis, not use oxygen as a reactant in the way described in some wrong options.

Answer:

C. Noah is correct. Oxygen is a product of photosynthesis; intense light would increase the amount of oxygen in the water.