Discussion:
1. The color of the indicator in set A turns yellow. This is because there is a high concentration of carbon dioxide in the water. Respiration of the fish oxygen and gives out carbon
2. The color of the indicator in set B remains red. This is because plants carry out photosynthesis in the presence of sunlight. This process uses up carbon dioxide in the water.
3. The color of the indicator set C turns yellow. In the absence of sunlight, use up for the respiration process. the plants
4. The color of the indicator in set D remains red. Respiration of the fish uses up the oxygen that is released by the plants through photosynthesis. On the other hand, the fish release carbon dioxide, which is essential for the photosynthesis process.
5. Set D shows interaction between the fish and the plants. These organisms are interdependent on one another for survival.
Conclusion:
Interaction between organisms and the environment is important in order to maintain balance in an ecosystem.