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. Ater this initial period, students incrementally increased the light intensity to investigate the relationship between light intensity and photosynthetic rate.
Figure 2.6 shows the change in carbon dioxide concentration over time for a chamber containing a water hyacinth.
A) According to Figure 2.5, the initial photosynthesis-stimulating period lasted approximately: (1 point)
5 minutes
50 minutes
20 minutes
B) 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 point)
Ο 300 με/m2
Ο 100 με/m2
1,000 E/m2/s
80 minutes
LED Irradiance
1,000
500
20
40 Time (min)
Figure 2.5 shows the light intensity (LED irradiance) over time for a chamber containing a water hyacinth
CO, Concentration
1,060
60
80
1,000-
CO, (ppm)
00
LED)
A) According to Figure 2.5, the initial photosynthesis-stimulating period lasted approximately:
20 minutes
B) 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 μE/m2/s