Stomata are pores on the surfaces of the leaves and stems of

Last updated: 7/9/2022

Stomata are pores on the surfaces of the leaves and stems of plants that regulate gas exchange between the plants and the atmosphere. Researchers found that the stomata density on the leaves of a species of plant change as the concentration of CO₂ in the atmosphere changes. When grown at 350 ppm CO₂ the plant has an average density of 300 stomata per mm², but when grown at 400 ppm CO₂ the plant has an average density of 250 stomata per mm². Which of the following best describes how the ratio of the density of stomata (stomata per mm²) per CO₂ concentration (ppm CO₂) changes as the CO₂ concentration increases? A The ratio decreases from 0.86 to 0.63, because fewer stomata are needed at higher CO₂ concentrations. B The ratio decreases from 1.6 to 1.2, because fewer stomata are needed at higher CO₂ concentrations. C The ratio increases from 0.63 to 0.86, because more stomata are needed at higher CO₂ concentrations. D The ratio increases from 1.2 to 1.6, because more stomata are needed at higher CO₂ concentrations.