Water enters into the root hair from the soil in its normal condition because the osmotic pressure of the soil solution

Options

A. Remains lesser than that of root hair sap
B. Remains equal to that of root hair sap
C. Remains higher than that of root hair sap
D. And that of root hair sap remains zero

Answer

**Step-by-Step Text Solution:**

1. **Understanding Water Absorption in Plants:**
Water enters the root hairs of plants from the soil. This process is crucial for the plant's survival as it provides the necessary water and minerals.

2. **Defining Soil Solution:**
The soil solution is a dilute mixture of minerals and water. It contains solutes (minerals) in low concentration, which means the osmotic pressure of the soil solution is low.

3. **Osmotic Pressure Comparison:**
Osmotic pressure (OP) is the pressure required to prevent the flow of water across a semipermeable membrane. In this case, we compare the osmotic pressure of the soil solution to that of the root hair sap. Since the soil solution has a low concentration of solutes, its osmotic pressure is also low.

4. **Root Hair Sap Concentration:**
In contrast, the sap within the root hairs has a higher concentration of solutes (minerals) compared to the soil solution. This results in a higher osmotic pressure in the root hair sap.

5. **Direction of Water Movement:**
Water moves from an area of lower osmotic pressure (soil solution) to an area of higher osmotic pressure (root hair sap). This movement occurs due to osmosis, where water travels from a hypotonic solution (soil) to a hypertonic solution (root hair sap).

6. **Conclusion:**
Therefore, the correct statement is that the osmotic pressure of the soil solution is less than that of the root hair sap, which facilitates the movement of water into the root hairs.

**Final Answer:**
The osmotic pressure of the soil solution is less than the osmotic pressure of the root hair sap.

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