Water moves up against gravity and even for a tree of `20m`height the tip receives water within two hours . The most important physiological phenomenon which is responsible for the upward movement of water is `"______"`

Options

A. guttation
B. evaporation
C. transpiration
D. none of these.

Answer

C

Explanation

According to transpiration pull theory due to transpiration the water column inside the plant comes under tension This is called transpiration pull On account of this tension, the water column is pulled up passively from below to top of the plant (almost like a rope).A tension of one atmosphere is sufficient to pull water to a heigher of about `20` meters.