Guard cells have a crucial function in controlling transpiration

Concept: The above given statement is true.

1. The cells that enclose each stomach are called guard cells. They aid in regulating the rate of transpiration by opening and closing the stomata. 
2. Guard cells play an important role in controlling transpiration. The kidney-shaped cells known as guard cells guard the stomata and are in charge of opening and closing the hole. 
3. It has been demonstrated that it also contains chloroplasts, which give them a photosynthesis site in addition to directing the gas exchange.