Question

From the following processes choose the one which does not helps for the absorption of water from the soil by roots :

• A. Root Pressure
• B. Cohesion
• C. Transpiration
• D. Osmosis

Answer 1

Answer:

B. Cohesion

Based on the standard choices for this biology question, the process that does not directly help with the absorption of water from the soil by roots is Cohesion (if presented among options like Osmosis, Transpiration pull, and Root pressure).

While cohesion is fundamentally important to the plant, it serves a distinct role in water movement. Here is how these processes compare:

## Processes That Help in Water Absorption

* Osmosis: This is the primary physical process by which water enters root hairs. Because root cells have a higher solute concentration than the surrounding soil moisture, water naturally moves across the semipermeable cell membranes into the roots.

* Transpiration (Transpiration Pull): As water evaporates from the leaves, it creates a powerful negative pressure or "suction pull" throughout the vascular system. This upward tension actively pulls more water from the soil into the roots.

* Root Pressure: The active accumulation of mineral ions in the root xylem lowers water potential, forcing water into the roots from the soil via osmosis. This creates a positive hydrostatic pressure that pushes water upward.

## Why Cohesion is the Exception

* Cohesion: This is the mutual attraction force between water molecules themselves. While it is absolutely critical for keeping the continuous column of water from breaking as it travels up the narrow xylem tubes, cohesion is a property responsible for the upward transport of water through the stem, rather than the initial absorption mechanism from the soil into the roots.