Question

How does the ascent of sap occur in tall trees?

Answer 1

Hint: Ascent of sap is the phenomenon in which water from the roots are transported to the other parts of the plant, the presence of a pull is essentially for the transport of water is more important in the case of tall plants.
Water has qualities like adhesion, cohesion, capillary action, and surface tension which aid in the transport of water up the plant from the roots.

Complete answer:
Ascent of sap is the process of transport of water and other ions and minerals found on the soil, from the roots towards the higher areas of the plants.
In the case of tall plants, ascent of sap translocates water and minerals upwards towards the shoot, leaves, and the flower utilizing the action and stress created by the transpiration.

The stomata in the leaves are said to lose water and hence creating transpiration stress in the whole plant body, this promotes the absorption of more water by the roots and the transport of water from the roots towards the leaves where the transpiration stress is seen. This transpiration pull is aided by properties of water like the cohesion - an attraction in between water molecules, adhesion - the force of attraction between water molecules and the other cells, and the surface tension.

Note: In short plants root pressure can translocate water and minerals to the plant but still the property of transpiration pull is shown in all types of plants whether long or short, it is not restricted to only tall plants.