What happens when a plant does not get enough water and starts to wilt?

When a plant does not receive enough water and begins to wilt, it typically responds to the stress by closing its stomata. Stomata are tiny openings on the leaves that allow for gas exchange, where carbon dioxide enters for photosynthesis and oxygen is released as a byproduct. By closing its stomata, the plant reduces water loss through transpiration, which is the process of water evaporating from the leaf surface.

In this stressed state, the plant effectively limits not only the transpiration process but also the intake of carbon dioxide, as the stomata are the primary pathways for this gas to enter the leaf. Although the plant may be facing a scarcity of water, it does not paradoxically initiate transpiration; rather, it conserves resources to survive in adverse conditions. Thus, as the stomata close to combat wilting, carbon dioxide intake is halted, securing the plant's remaining water supply.

The other choices do not accurately reflect how a plant typically responds to water scarcity. In the context of environmental stress, the crucial act of closing stomata signifies an adaptive mechanism to preserve water and maintain overall plant health during periods of drought.