Tag: long distance transport of water

Guttation is the 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.

Root pressure is osmotic pressure within the cells of a root system. Root pressure is generated by active uptake of minerals by roots, which lowers water potential of root cells and water flows inside the cells along its concentration gradient. Thus, on the cutting of shoot, excretion of watery substance from cut side occurs.

All plants do not show guttation. It is restricted to about 345 genera of herbaceous and some woody plants.
e.g., Garden Nasturtium, Oat Balsum, Tomato etc

Transpiration is the process where plants absorb water through the roots and then give off water vapor through pores in their leaves.

Guttation is the loss of water in the form of droplets along the margin and tips through special structures called hydathode. The guttational drops comprise of water various salts dissolved in it. 
Thus, the correct answer is option (B). 

Guttation is the loss of water in the form of liquid from the uninjured margins of the leaves is called guttation. The pores are known as hydathodes. The level of soil moisture is high which creates greater root pressure. This root pressure creates a force which allows exudation of water from the tips. It is favored when the transpiration is suppressed and the relative humidity is high
Thus the correct answer is option (A). 

Water exduation through hydathodes is known as guttation. Guttation is the process of loss of impure water (a dilute solution of different organic and inorganic substances) from plant infact, mostly from margins of leaves. It occurs when transpiration rate is very low as compared to rate of water absorption. Due to this root pressure is developed and water is pushed out through specialized pores at vein endings called hydrathodes. Each hydrathode is made up of group of loosely arranged achlorophyllous or colorless and parenchymatous cells called epithem. These cells help in absorbing a good percentage of inorganic and organic solutes present in the exudate. 

Guttation is the moisture emitted by plants during night time.

Root pressure is the pressure caused due to the accumulation of water in the root region. It is caused in the absence of transpiration so, due to excess water in the plant, it exudes water through leaves in morning time it is called guttation.