What do you think will happen if there were no stomata in the epidermis of the stem or leaves?
If there were no stomata in the epidermis of the stem or leaves, the plant would be unable to perform gaseous exchange. Stomata are the essential pores in the epidermis that allow gases to pass through the plant's outer layer.
Furthermore, without stomata, the process of transpiration, which is the evaporation of water vapours through these pores, would not occur. Since transpiration helps in water transportation by creating a transpiration pull in the xylem, the absence of stomata would severely disrupt the upward movement of water through the plant.
Explanation
The textbook context explicitly states that stomata in the epidermis help in gaseous exchange and transpiration (evaporation of water vapours). It further explains that transpiration helps in water transportation by creating a transpiration pull in the xylem. Therefore, the absence of stomata would halt both gaseous exchange and the transpiration pull required for water transportation.