Question 11(B)

Explain the mechanism by which the water is transported in plants?

Answer:

Water absorbed by the roots is transported to various parts of the plant through the xylem.

• It enters the root hairs from the soil by osmosis and then passes cell to cell till it reaches the xylem vessels.

• From the xylem, water is carried upward due to three main forces:

  1. Root pressure – pushes water upward.

  2. Capillary action – helps water rise in the narrow xylem tubes.

  3. Transpiration pull – evaporation of water from stomata creates a suction force that pulls water upward; this is the main force for ascent of sap.

• The cohesion and adhesion of water molecules maintain a continuous water column in xylem, preventing breakage.

Thus, water absorbed from the soil reaches the leaves, where it is used in photosynthesis, maintaining cell turgidity and other functions.