Question

Explain with activities where plants need H₂O and CO₂.

Answer 1

Carbon dioxide and water are very important for the process of photosynthesis:

Aim:

To demonstrate that carbon dioxide and water are the two basic components of plants

Apparatus required:

1. A healthy potted plant
2. A wide-mouthed glass bottle with a split cork
3. Potassium hydroxide solution (KOH)
4. Starch solution.

Procedure:

1. A wholesome potted plant, and keep it there for two to three days.
2. In a glass bottle with a big mouth After adding 10 to 15 ml of potassium hydroxide solution, the cork was split vertically.
3. The split cork was used to enter half of the leaf, leaving the other half exposed to the air.
4. For four hours, the entire installation was left undisturbed.
5. The leaf was removed from the plant after 4 hours and treated with a starch solution.

Observation from the experiment:

1. The leaf's half that was retained in the glass bottle with the KOH solution did not change color.
2. The other half of the section that was exposed to the environment changed to a dark brown color, indicating the presence of starch.

Conclusion:

1. We can infer that water and carbon dioxide is necessary for photosynthesis.
2. However, the half of the leaf that was inside the glass bottle did not absorb carbon dioxide and water, therefore the photosynthetic process did not take place there.
3. Both portions of the leaf received the same quantity of water, chloroplasts, and sunlight.