Explain about transpiration pull and cohesion of water theory.
Ascent of sap is the phenomenon which helps to uptake water from roots to tip of plants. Many theories have been purposed to explain ascent of sap.
Ascent of sap by transpirational pull was given by Dixon and Joly.
According to this theory the column of water is pulled upwards by the tension created due to the loss of water by transpiration in leaves.
Water forms a continuous column extending between the root and the leaf parenchyma cells through the xylem ducts. This is also called Hydrostatic...