Stomata close during high intensity light to prevent excessive transpiration but why did they close during low intensity of light? Please explain in easy- understand language because i'm in just 10th standard.
1$\begingroup$ Think closed state as default state, it is the light which opens the stomata, So in the absence of light stomata go backs default(closed or resting or inactive) state. $\endgroup$– JM97May 19, 2017 at 6:31
$\begingroup$ Do you have a source in support of your assertion that high light intensity causes stomata to close? $\endgroup$– Alan BoydMay 19, 2017 at 8:23
The primary function of open stomata is to promote gas exchange in leaf tissue: atmospheric carbon dioxide is a substrate for photosynthesis. A side effect of opening the stomata is an increase of water loss through transpiration. If light intensity is low then photosynthesis will be depressed: under these conditions it makes sense to close the stomata to conserve water.