Question

Briefly describe the mechanism that moves water up the stem from the roots to the leaves in igcse biology

Answer 1

The mechanism responsible for moving water up the stem from the roots to the leaves is known as the transpiration-cohesion-tension mechanism. It relies on three factors: transpiration, cohesion, and tension.

Step-by-step explanation:

The mechanism responsible for moving water up the stem from the roots to the leaves is known as the transpiration-cohesion-tension mechanism. This process relies on three key factors:

1. Transpiration: Water evaporates from the stomata on the leaves' surface, creating a negative pressure gradient.
2. Cohesion: Water molecules are attracted to each other, allowing them to form a continuous column inside the xylem vessels.
3. Tension: Water is pulled upwards by this cohesive force, creating a suction effect throughout the plant.

This mechanism ensures a steady flow of water and nutrients from the roots to the leaves, supporting various plant processes such as photosynthesis.

Learn more about Water movement in plants