A plant is grown in bright light at 15 °C and its photosynthesis rate does not rise when the light is increased further. Raising the temperature to 25 °C increases the rate. What was limiting the rate at 15 °C?
Answer and explanation
Correct answer: D. Temperature
- Step 1: More light had no effect, so light was not limiting.
- Step 2: Adding heat raised the rate, so temperature was the limiting factor.
Answer
Temperature.
Why not the others: Light intensity: more light did not raise the rate. Chlorophyll concentration: it was not changed in the experiment. The plant's age: this was not tested.
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