AP BIOLOGY

Detailed explanation-1: -When ions from the soil are actively carried into roots which would be of the vascular tissue, it creates a positive pressure inside the roots known as transpiration therefore this process of water movement which is upward is caused by this pressure, also known as the root pressure.

Detailed explanation-2: -As water molecules evaporate from plant leaves, they attract the water molecules still in the plant, helping to pull water up through the stems from the roots. The combination of transpira-tion and capillary action delivers the water from the bottom to the top of a plant.

Detailed explanation-3: -As transpiration occurs, it deepens the meniscus of water in the leaf, creating negative pressure (also called tension or suction). The tension created by transpiration “pulls” water in the plant xylem, drawing the water upward in much the same way that you draw water upward when you suck on a straw.

Detailed explanation-4: -The direction of xylem transport is upwards and unidirectional i.e. from roots to other plant parts. The water column moves only upwards because of the two forces, transpirational pull, and positive root pressure.

Detailed explanation-5: -The process by which the plant body releases water in the form of vapours through its aerial portions is known as transpiration.