Two green plants are kept separately in oxygen-free containers, one in the dark and the other in continuous light. Which one will live longer? Give reasons.

The one in continuous light will live longer.

1. Plant kept in continuous light tends to live longer as compared to the other plant kept in dark.
2. Plants perform the photosynthesis process in the presence of light or during the day whereas, at night or in dark the plant performs the process of respiration.
3. During respiration, carbon dioxide is released out of the plant and here, the plant present in dark will have carbon dioxide accumulated in the container.
4. Due to increase in carbon dioxide, the oxygen availability will be less and it will lead to the death of the plant.
5. On the other hand, plants kept in light will perform photosynthesis and utilize carbon dioxide while releasing oxygen in the container.
6. This will help in maintaining the availability of oxygen for its respiration in dark. Hence, making it survive for a longer period of time.