When a mustard plant seedling is transferred to an environment with higher levels of carbon dioxide, the new leaves have a lower stomata-to-surface-area ratio than do the seedling’s original leaves.

Which of the following best explains how the leaves from the same plant can have different stomatal densities when exposed to an elevated carbon dioxide level?

When a mustard plant seedling is transferred to an environment with higher levels of carbon dioxide, the new leaves have a lower stomata-to-surface-area ratio, it is because the concentration of carbondioxide is high in the surrounding environment so the plant produce small leaves having less number of stomata. If the concentration of carbondioxide is lower so big leaves are produced having maximum number of stomata.