Land plants grow in soils which possess an osmotic concentration

Options

A. Hypotonic in relation to cells
B. Hypertonic in relation to cells
C. Isotonic in relation to cells
D. ultratonic in relation to cells .

Answer

To answer the question regarding the osmotic concentration of soils in which land plants grow, we can follow these steps:

### Step-by-Step Solution:

1. **Understanding Osmosis**:
- Osmosis is the movement of water across a semi-permeable membrane from an area of lower solute concentration (hypotonic) to an area of higher solute concentration (hypertonic).

2. **Identifying Plant Needs**:
- Land plants require water for various physiological processes such as photosynthesis, nutrient transport, and maintaining turgor pressure.

3. **Analyzing Soil Conditions**:
- The soil must have a certain osmotic concentration to facilitate the uptake of water by the plant roots.

4. **Defining Hypotonic Solutions**:
- A hypotonic solution has a lower concentration of solutes compared to the inside of the plant cells. This means that the concentration of water (solvent) is higher in the soil than in the plant cells.

5. **Movement of Water**:
- When the soil is hypotonic relative to the plant cells, water will move from the soil into the plant roots through the process of endosmosis. This is because water moves from areas of high concentration (soil) to areas of low concentration (inside the plant cells).

6. **Conclusion**:
- Therefore, the correct answer to the question is that land plants grow in soils which possess an osmotic concentration that is hypotonic in relation to their cells.

### Final Answer:
**Option A: Hypotonic in relation to cells.**

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