Question

A column of water within xylem vessels of tall trees does not break under its weight because of
A. dissolved sugars in water
B. tensile strength of water
C. lignification of xylem vessels
D. positive root pressure

Answer 1

Correct Answer - B
A column of water within xylem vessels of tall trees does not break under its weight because of high tensile strength of water, i.e., an ability to resist a pulling force. This high tensile property depends on cohesion, adhesion and surface tension property of water. Due to these forces only transpiration driven ascent of xylem sap occurs.