HORTICULTURE

Detailed explanation-1: -Closing and opening of stomata is controlled by guard cells. If guard cells are turgid [swollen due to water entry] they open the stomata. When they lose water [plasmolysis], and subsequently become less turgid, they close stomata.

Detailed explanation-2: -Guard cells use osmotic pressure to open and close stomata, allowing plants to regulate the amount of water and solutes within them.

Detailed explanation-3: -Stomata are surrounded by two specialized cells called guard cells (Figure 17.1. 2.2. 1). Stomata must open to allow the gas exchange of carbon dioxide and oxygen for efficient photosynthesis (see Photorespiration), and light thus typically triggers stomatal opening.