the goal:

Revealing how photosynthesis and cellular respiration work together in an ecosystem.

Materials and tools:

Bromothymol blue (BTB) solution - Glass beaker - Test tubes - Aluminum foil - Aquatic plant.

Steps:

1- Add a quantity of bromothymol blue (BTB) solution to a glass beaker using a pipette.

2- Gently blow into the solution until it turns yellow.

3- Transfer the solution into a test tube and repeat the previous two steps again and transfer the solution into another test tube.

4- Cover one of the test tubes with aluminum foil.

5- Place an aquatic plant in each of the test tubes, then seal them tightly.

6- Leave the test tubes in dim light overnight, then record your observations.

Note:

We observe that the solution turns blue in the test tube that is not covered with aluminum foil, while it remains yellow in the covered test tube.

Conclusion:

The covered test tube with aluminum foil represents a control group, indicating that the plant only used carbon dioxide in the presence of light to carry out photosynthesis.

During photosynthesis, the plant takes in carbon dioxide and converts it into sugar and oxygen using light energy. Both plants and animals carry out cellular respiration, which uses oxygen to burn carbohydrates and produce carbon dioxide. The two processes are interdependent.

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