Tag: water absorption and ascent of sap in plants

Guttation is the loss of water in liquid form as a dilute solution from the leaf tips. The uninjured leaf tips have hydathodes or water stomata. Under conditions of low transpiration dilute solution of minerals oozes out through them under the influence of increased root pressure. Water potential depends on the number of water molecules in the system. More the number of water molecules, greater will be the water potential. Under the conditions, when there are more water molecules in the system, water potential is expected to be higher. There is more water molecules will be stuffed up inside leaf in the intercellular spaces giving rise to a positive water potential. There is low transpiration and guttation takes place.

A deficiency of 0xygen always causes a corresponding decrease in the rate of mineral absorption. It is probably due to the unavailability of ATP. The increased oxygen tension helps in increased uptake of salts. So the given statement is false.

Cohesion is the mutual attraction between water molecules. Adhesion is the attraction of water molecules to polar surfaces (such as walls of xylem vessels). These both forces together helps in the formation of a thin, unbroken column of water which leads to the mass flow of water in apoplastic pathway.