The Elodea trial was repeated at three CO2 concentrations: low (0.04 percent), medium (0.4 percent), and high (1 percent). Each curve plots O2 production vs light intensity.
What does the comparison demonstrate?
- A
CO2 is irrelevant once a saturation point is reached.
- B
Only the medium CO2 condition supports photosynthesis.
- Ccheck_circle
CO2 concentration sets the maximum rate even when light is abundant.
- D
Light is the only factor that controls photosynthesis.
Explanation
Each curve plateaus at a higher rate as CO2 increases, showing that CO2 imposes a ceiling on photosynthesis once light is saturating.