A student creates an experiment to determine the effects of oxygen on the growth of a water plant. The student fills three containers with water and adds an aquatic plant to each. Container 1 is open to the air, container 2 has a lid that prevents the exchange of air, and container 3 has a lid with a tube that pumps air into the container. After three weeks, the student observes that containers 1 and 3 have healthy green plants, while the plant in container 2 has not grown, and the leaves show browning areas. Which explanation provides the reason for the difference in the growth of the plant in container 2?