Tag: transpiration

The movements showed by plants can be classified broadly as
(1) Hygroscopic- due to loss or gain of water and
(2) Vital- due to irritability of the cytoplasm. 
Nyctinasty or sleep movements are rhythmic movements, also called as sleep movements and are caused by relative changes in cell size on the opposite sides of the leaf base called as pulvinus. 

Guttation is the loss of water through water stomata (hydathodes) in solution form as a dilute solution of mineral salts. This process occurs, when the absorption of water exceeds transpiration i.e., when plants are absorbing water actively. A positive root pressure is built up under the influence of which excess water simply oozes out through the dead ends of xylem tracheids and vessels. Thus, the correct answer is option D.

Guttation is the loss of water through water stomata (hydathodes) in solution form as a dilute solution of mineral salts. When the absorption of water exceeds transpiration i.e., when plants are absorbing actively, a positive root pressure is built up under the influence of which excess water simply oozes out through the dead ends of xylem tracheids and vessels. A loose collection of cells called as epithem, present at the dead ends of xylem tracheids and vessels. The epithem cells do not regulate opening and closing of hydathodes. Thus, hydathodes are unregulated openings and are always open. Thus, the correct answer is option D.

Guttation is the loss of water through water stomata (hydathodes) in solution form as a dilute solution of mineral salts. The term was coined by Burgerstein in 1887. When the absorption of water exceeds transpiration i.e., when plants are absorbing actively, a positive root pressure is built up under the influence of which excess water simply oozes out through the dead ends of xylem tracheids and vessels. Thus, the correct answer is option A.

Guttation is the loss of water in solution form through hydathodes. The water lost in guttation is a dilute solution of mineral salts. The guttation occurs under the influence of positive root pressure and depends on environmental conditions. It is generally observed when atmospheric humidity is high so that rate of transpiration is low and soil is well watered. Thus, the correct answer is option B.

Guttation is the loss of water through water stomata (hydathodes) in the form of the dilute solution of mineral salts. When the absorption of water exceeds transpiration i.e., when plants are absorbing water actively, a positive root pressure is built up under the influence of which excess water simply oozes out through the dead ends of xylem tracheids and vessels. This usually happens during early morning hours when transpiration is low.

The exudation of xylem sap at the edges or tips of the leaves of some vascular plants, like grasses is called guttation. Unlike transpiration, it takes place only in certain conditions like cool and highly humid atmosphere. It is because plants can absorb up a limited amount of water. The excess water is secreted from the roots through the xylem and out through the hydathodes or water glands.

When the plant absorbs water by their own, it is called active absorption. It takes place when transpiration is low and amount of water in the soil is high. In this case root hairs play the major role in the absorption of water. Root pressure is the positive pressure that develops in the roots of plants by the active absorption of nutrients from the soil. It causes sap to rise through a plant stem to the leaves. Guttation is the exudation of xylem sap on the tips or edges of leaves of some vascular plant. According to the passive absorption, root hairs do not play any role in absorption. It takes place only when transpiration rate is high. So, the correct option is D.

The process of exudation of sap on the tips or edges of leaves in plant is called guttation. It takes place only under certain conditions like cold and high relative humidity in the atmosphere. It occurs through the specialized structures called hydathodes. They are generally restricted to the apex or the edges of the margins of leaves. Structurally, hydathodes consist of a simple pore in the epidermal layer found at the tip.

Guttation is the excretion of drops of xylem sap on the tips or edges of leaves of some vascular plants, such as grasses. It is the loss of water in liquid form through hydathodes.