Question
A column of water within xylem vessels of tall trees does not break under its weight because of
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Dissolved sugars in water
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Tensile strength of water
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Lignification of xylem vessels
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Positive root pressure
Solution
B.
Tensile strength of water
A column of water within xylem vessels of tall tree does break under its weight because of high tensile strenght 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 drive ascent of xylem sap occurs.
