How might a high stomatal density on plant leaves affect the Calvin cycle during cool days?
A.Higher stomatal density would increase the amount of carbon incorporated into RuBP.
B.Higher stomatal density would decrease the production of rubisco in mesophyll cells.
C.Higher stomatal density would decrease the amount of ADP released in the reactions.
D.Higher stomatal density would increase the amount of NADPH produced during the cycle.
A. Higher stomatal density would increase the amount of carbon incorporated into RuBP.
Stomata are small openings on plant leaves that allow for gas exchange, primarily the intake of carbon dioxide (CO2) needed for photosynthesis. During cool days, the stomatal density (number of stomata per unit area) on plant leaves may increase as a response to environmental conditions.
With a higher stomatal density, more stomata are available for CO2 uptake from the atmosphere. This increased availability of CO2 would result in an increased amount of carbon being incorporated into ribulose-1,5-bisphosphate (RuBP), a key molecule in the Calvin cycle. The Calvin cycle uses RuBP as a starting material and carbon dioxide as a source of carbon to produce organic molecules like glucose.
Therefore, a high stomatal density on plant leaves during cool days would enhance the efficiency of the Calvin cycle by increasing the amount of carbon available for fixation into RuBP. Option A is the correct answer.