Why do stomata open and close? why is this an advantage for the leaf?

The advantages of open stomata is as follows, Transpiration is the process of evaporation of water from the leaves and stems to the atmosphere. The stomata close when the guard cells shrink, which in turn ceases the transpiration. Opening of stomata allows the process of transpiration, so the root cells do not die.

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explanation:

the answer is lactic acid from anaerobic respiration. the acid in lactic acid is what creates sore and burning muscles. if you think about how acid burns that will give you a clue for questions like this.