Living Environment Regents Practice Test

What gas was produced by the elodea plant during the student's experiment?

1. Carbon dioxide

2. Nitrogen

3. Oxygen

4. Hydrogen

The correct answer is: Oxygen

In the context of the experiment involving the elodea plant, the correct answer is oxygen. Elodea, like many aquatic plants, undergoes photosynthesis, a process that converts light energy into chemical energy, producing glucose and releasing oxygen as a byproduct. During this process, the plant takes in carbon dioxide from the surrounding water and, using sunlight, converts it into energy while expelling oxygen into the environment. The production of oxygen is particularly significant in aquatic ecosystems, as it contributes to the overall oxygen levels in the water, which is essential for the survival of aerobic organisms, including fish and other aquatic life. This relationship highlights the importance of plants in maintaining ecological balance. Other gases, such as carbon dioxide, nitrogen, and hydrogen, do not represent the product of photosynthesis in this case. Carbon dioxide is used by the plant during the process rather than produced; nitrogen is typically a stable gas found in the atmosphere which plants do not produce; and hydrogen, while part of the water molecules used in photosynthesis, is not released in significant amounts as a gas during this process.