Tag: long distance transport of water

(A) Vein ending - Guttation

Guttation is the process of loss of water from the surface of leaves in the form of water droplets. The margins of leaves contain opening called as hydathodes from where the guttation takes place.

Guttation is the excretion of drops of xylem sap on the tips or edges of leaves of some vascular plants, such as grasses. In the absence of light, plant loose excess water in the form of liquid through hydathodes because most plants have their stomata closed at night. When there is a high soil moisture level, water will enter plant roots, because the water potential of the roots is lower than in the soil solution. The water will accumulate in the plant, creating a slight root pressure. The root pressure forces some water to exude through special leaf tip or edge structures, hydathodes or water glands, forming drops. Therefore, the correct answer is option A.

Guttation is the term used to refer to the phenomenon in which droplets of eater secreted from the pores in leaves of plants. It occurs through specialised pores called hydathodes. It takes place at night and in conditions of high root pressure and low transpiration. It occurs in plants growing under conditions of high soil moisture and high humidity. Thus, the correct answer is 'It occurs through specialised pores called hydathodes.'

Guttation is loss of water in liquid form as a dilute solution from uninjured 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.

Guttation is the excretion of drops of xylem sap on the tips or edges of leaves of some vascular plants through hydathode, such as grasses. It occurs in the absence of light i.e., at night and thus it is present on the edge of leaves in the early morning.

Transpiration is the loss of water through stomata in vapour form. Transpiration is regulated through guard cells. Guttation is the loss of water in liquid form through hydathodes. Hydathodes are free ends of vascular supply of leaves. Hydathodes are always open and not regulated by any cells.

Guttation is the loss of water in  the form of liquid through hydathodes or water stomata. It occurs due to positive root pressure and serves to remove excess water from the plant. As xylem sap is having dissolved minerals, water droplets that ooze out from them contain solution of water and minerals. 

Transpiration is defined as loss of water as gas or vapour from leaves through the stomatal pore. If there is less transpiration due to high atmospheric humidity and the soil is well watered; there will be an increase in root pressure. The increased root pressure leads to oozing out of the solution of minerals from hydathodes (called as guttation) and other openings (called as bleeding). Thus, the correct answer is option D.