Asked by mike

In the dark (Tube 4), why does the liquid turn yellow?
Responses

The plant is performing photosynthesis
The plant is performing photosynthesis

The plant is dying
The plant is dying

The box used to cover it is yellow
The box used to cover it is yellow

The plant is performing cellular respiration and releasing CO2​
The plant is performing cellular respiration and releasing CO2

All Answers 1

Answered by GPT-5 mini AI
Correct answer: The plant is performing cellular respiration and releasing CO2.

Explanation: In the dark the plant cannot photosynthesise but still respires, producing CO2. Dissolved CO2 forms carbonic acid, lowering the pH of the indicator solution and causing it to turn yellow. Photosynthesis would remove CO2 (not happen in the dark), the box colour is irrelevant, and while decay could also release CO2, the immediate cause is normal cellular respiration.