Question

figure 1. effect of light intensity and growth period on the rate of photosynthesis in sage plants. error bars represent ±2se, using light - filtering cloths, scientists exposed sage plants to four different light intensities. half of the sage plants were exposed to light for 60 days, while the other half were exposed to light for 75 days. the rate of photosynthesis in each plant was then determined (figure 1). which of the following statements best describes the data? a at 100% light intensity, the rate of photosynthesis was higher in plants that were treated for 60 days than in plants that were treated for 75 days. b at 75% light intensity, the rate of photosynthesis was unaffected by an increase in treatment time. c at 50% light intensity, the rate of photosynthesis was the same as the rate of photosynthesis at 75% light intensity, regardless of the length of treatment time. d at 25% light intensity, the rate of photosynthesis was higher in plants treated for 75 days than it was in plants treated for 60 days.

Explanation:

The bar graph shows that at 100% light intensity, the bar for 60 days (dark gray) is taller than the bar for 75 days (white), indicating a higher photosynthesis rate. Other options are inconsistent with the data: B (75% light intensity shows a difference between 60 and 75 days), C (50% and 75% light intensities have different rates), D (25% light intensity shows no clear higher rate for 75 days). Thus, A best describes the data.

Answer:

A. At 100% light intensity, the rate of photosynthesis was higher in plants that were treated for 60 days than in plants that were treated for 75 days.