The graph shows a correlation between light intensity and CO2 flux in leaves. Why is maximum CO2 given off when the light intensity is zero?
The graph shows a correlation between light intensity and CO2 flux in leaves. Why is maximum CO2 given off when the light intensity is zero?
The correct option is B Only respiration is occurring
Blackman (1905) studied the effect of CO2 concentration, light intensity and temperature on the rate of photosynthesis.
When no light was provided to photosynthetic material, it did not perform photosynthesis. Instead, it evolved CO2 and absorbed O2 from its environment. He provided light of low intensity (say 150-foot-candles) and found photosynthesis to occur.
When light intensity was increased (say 800-foot candles), the rate of photosynthesis increased initially but soon it levelled off. The rate of photosynthesis could be further enhanced only on the increase in availability of CO2. Thus, initially, light intensity was limiting the rate of photosynthesis.
Hence, the correct answer is 'Only respiration is occurring'.
Blackman (1905) studied the effect of CO2 concentration, light intensity and temperature on the rate of photosynthesis.
When no light was provided to photosynthetic material, it did not perform photosynthesis. Instead, it evolved CO2 and absorbed O2 from its environment. He provided light of low intensity (say 150-foot-candles) and found photosynthesis to occur.
When light intensity was increased (say 800-foot candles), the rate of photosynthesis increased initially but soon it levelled off. The rate of photosynthesis could be further enhanced only on the increase in availability of CO2. Thus, initially, light intensity was limiting the rate of photosynthesis.
Hence, the correct answer is 'Only respiration is occurring'.
