MCAT Biology

Mallory has four aquatic plants of the same size and species. She submerges each plant in a separate beaker filled with 200 mL of water. She then sets each beaker under a different intensity of light. Mallory 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 min period.Which of the following statements best explains Mallory’s observations?