NEET BIOLOGY

Detailed explanation-1: -Two highly specialized cells, the guard cells that surround the stomatal pore, are able to integrate environmental and endogenous signals in order to control the stomatal aperture and thereby the gas exchange.

Detailed explanation-2: -The opening and closing of stomata are controlled by specialized cells called guard cells. The turgor pressure in the guard cells controls the opening and closing of the guard cells. Stomatal pores open when guard cells enlarge as a result of water absorption and close when guard cells shrink.

Detailed explanation-3: -Potassium (K) is significant due to its function in controlling stomatal opening and shutting.

Detailed explanation-4: -The increase in osmotic pressure in guard cells during stomatal opening is mainly due to an accumulation of potassium ions. The corresponding anions are usually malate, but depending on the plant species, sometimes also chloride. Complex metabolic reactions occur during the opening process with malate (Fig. 8.4).