Guard cells, subsidiary cells, and stomatal aperture
Transpiration and gaseous exchange
Solution
The stomatal apparatus is made up of the guard cells, which enclose the stomatal pore and regulate the opening and closing of the stomata, the subsidiary cells, which are a few epidermal cells in the vicinity of the guard cells that have become specialised in shape and size, and the stomatal aperture, which is the opening in the stomata through which gaseous exchange and transpiration occur.