To answer your questions based on the provided data:
Question 1 According to Figure 2.5, the initial photosynthesis-stimulating period lasted approximately:
- 50 minutes
Question 2 Based on the data in Figures 2.5 and 2.6, which light intensity causes a water hyacinth leaf to absorb carbon dioxide at the fastest rate?
- 1,000 E/m2/s
These responses are hypothetical given the context you described, as I do not have access to the figures. For accurate answers, it is important to refer directly to the visual data in Figures 2.5 and 2.6.