Question

Mike has four aquatic plants of the same size and the same species. He submerges the plants in a separate beaker filled with 200 mL of water. He then sets each beaker under a different intensity of light. Mike observes that, of the four plants, the plant in the beaker under the most intense light gives off the most gas bubbles in a 20 minute period. Which of the following statements best explains Mike's observations?
A. Cells decompose most quickly under the most intense light.
B. Water evaporates from plants faster under the most intense light.
C. Photosynthesis occurs at the highest rate under the most intense light.
D. Gases in the leaves of plants expand most under the most intense light

Answer 1

C. Photosynthesis occurs at the highest rate under the most intense light.

This is the most plausible explanation for why the plant under the most intense light would give off the most gas bubbles in a 20 minute period. The light intensity directly affects the rate of photosynthesis, so the plant receiving the most intense light would be able to produce the most oxygen through photosynthesis.