Students in a biology class used lighted chambers to measure the photosynthetic rate of leaves from four common plant species: sunflower, water hyacinth, rhoeo, and pothos. A leaf was placed inside the chamber, and a flow of air was introduced. Sensors within the chamber recorded data on light intensity (LED irradiance), carbon dioxide concentration, air temperature, and relative humidity. The leaf was initially exposed to a constant light intensity of 300 μE/m2/s to stimulate photosynthesis. After this initial period, students incrementally increased the light intensity to investigate the relationship between light intensity and photosynthetic rate.Figure 2.5 shows the light intensity (LED irradiance) over time for a chamber containing a water hyacinthFigure 2.5 shows the light intensity (LED irradiance) over time for a chamber containing a water hyacinthFigure 2.6 shows the change in carbon dioxide concentration over time for a chamber containing a water hyacinth.Question 1According to Figure 2.5, the initial photosynthesis-stimulating period lasted approximately:(1 point)Responses80 minutes80 minutes5 minutes5 minutes50 minutes50 minutes20 minutes20 minutesQuestion 2Based 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 point)Responses300 μE/m2300 μE/m2100 μE/m2100 μE/m21,000 E/m2/s1,000 E/m2/s0 μE/m2/s

1 answer

To answer your questions based on the provided information about the light intensity and the carbon dioxide absorption rates for water hyacinth, we can analyze the descriptions of Figures 2.5 and 2.6.

Question 1:

According to Figure 2.5, the initial photosynthesis-stimulating period lasted approximately:

  • Please check the visual data for the specific duration indicated in the light intensity graph. Typically, if the initial constant light intensity was at 300 μE/m²/s, the period might last longer than the increments. If it indicates a clear segment on the graph marking this period, choose that duration accordingly.

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?

  • To determine this, you would look for the highest rate of carbon dioxide absorption recorded in Figure 2.6 corresponding to increasing light intensities shown in Figure 2.5. This would typically reflect the point at which carbon dioxide concentration decreases most rapidly, indicating uptake by the plant.

With the options provided:

  • 300 μE/m²/s
  • 100 μE/m²/s
  • 1,000 μE/m²/s
  • 0 μE/m²/s

Please review Figures 2.5 and 2.6 to find where the carbon dioxide concentration decreases most rapidly in relation to the light intensities to make your selection.

If you have access to the figures or can provide their details, I can assist you further in analyzing the data.