Question

The transport of sap from root to top of the plant is
A)Ascent of sap
B)Conduction
C)Transport
D)Translocation

Answer 1

Sap is a fluid held in the components of a plant's xylem cells (vessel elements or tracheids) or phloem sieve channel. Water and nutrients are borne in the plant by these cells.

Complete answer:
Root is usually a non-green, underground part of the plant.
It does not have nodes, leaves, and buds, but it is extensively branched. Root is well suited to its function of absorption of soil water, both morphologically and anatomically.

The upward movement of the water or the sap from the roots to the top of the plant is called the conduction or ascent of the sap.
It occurs through tracheids and xylem tissue vessels.

Xylem is a complex tissue made up of living and non-living cells. The xylem-conducting cells are typically non-living and include members of vessels and tracheids in different groups of plants. Both of these types of cells have thick, lignified secondary cell walls and are dead at maturity.

Although several mechanisms have been proposed to explain this phenomenon, the cohesion-tension mechanism has the most evidence and support. Although cohesion-tension has been criticized for, for example, the apparent existence of large negative pressures in some living plants, experimental and observational data favor this mechanism.

The transport of food from the leaves (where photosynthesis takes place) to the other parts of the plant is referred to as translocation. Food is transported through the vascular tissue known as phloem.

Vascular bundles in stem, roots and leaf veins form a continuous system of tubes which together form a transport system throughout the entire body of the plant. This process of transporting water and salts upwards through xylem and food upwards and downwards through phloem is called conduction.

Hence, the correct answer is option (A)

Note: The theory assumes that in the uppermost parts of the tallest trees, the xylem vessels are coated with thin film of sap. The sap interacts physically with the walls of the vessels: due to the forces of van der Waals, the film density varies with the distance from the wall of the vessel. This variation in density, in turn, produces a disjointing pressure, the value of which varies with distance from the wall.