If a soft stemmed plant is cut horizontally near the base of its stem with a sharp blade on early morning of a humid day, drops of solution ooze through cut stem. This is due to

Options

A. guttation
B. bleeding
C. transpiration pull
D. root pressure.

Answer

D

Explanation

If we cut a small soft-stemmed plant on a day , When there is plenty of atmospheric moisture early in the morning we will soon see drops of solution ooze out of the cut stem, this comes out due to the positive root pressure. If we fix a rubber tube to the cut stem as a sleeve we can actually collect and measure the rate of exudation and also determine the composition of the exudates Root pressure is a positive pressure that develops in the xylem sap of the root of some plants. It is a manifestation of active water absorption. Root pressure is observed in certain seasons which favour optimum metabolic activity and reduce transpiration. It is more during rainy season in the tropical countries and during spring in temperate habitats.