Question

what is ascent of SAP describe the mechanism of ascent of SAP in higher plant ?

Answer 1

Ascent of sap is the transport of water and minerals through xylem.. it is unidirectional
Ascent occurs as the loss of water takes place through stomata... this creates suction and water column rises in xylem
Stomata generates a transpirational pull.. through veins and midrib which are connected to xylem.
ascent of sap doesn't require energy it only functions due to the pull