water is pulled up the xylem by the process of
A process known as transpiration is responsible for pulling water up from the roots to the leaves through the xylem tissue. In transpiration, water evaporates from the leaves, causing more water to be pulled upwards. Xylem vessels are comprised of dead cells. Only the rigid cell walls of these cells remain, and these walls surround a narrow cavity, or lumen, through which water is drawn.