DENDROLOGY

Detailed explanation-1: -Guard cells regulate the opening and closing of stomatal holes, which are controlled by the process called osmosis. The entry of water into the stomata makes guard cells swell which leads to the opening of the stomata.

Detailed explanation-2: -The pore is opened by an increase in osmotic pressure in the guard cells, resulting in the uptake of water. The subsequent increase in cell volume inflates the guard cell and culminates with the opening of the pore.

Detailed explanation-3: -The solute potential resulting high concentrations of potassium, chloride, sucrose, malate, and nitrate in the cytosol drives the osmosis of water into the the guard cells. This increases turgor pressure, and the guard cells expand and bend, opening the stoma (Figure 17.1.