Question

What happens when a plant is losing too much water through transpiration?Stomata openStomata closeGuard cells swellRespiration increases

Answer 1

The guard cells swell when water flows into them, causing the stoma pore to open. Now, the stomata must open to receive carbon dioxide for photosynthesis. And the more open they are, the more plants transpire and lose water. Thus, the size of the stomatal opening is used by the plant to control the rate of transpiration and thus limit the levels of water loss from the leaf.

So that, we can conclude that the correct answer is:

Stomata close when a plant is losing too much water through transpiration