Optimum temperature for water absorption by plants is

Options

A. `0^(@)-5^(@)C`
B. `5^(@)-20^(@)C`
C. `20^(@)-25^(@)C`
D. `40^(@)-50^(@)C`

Answer

To determine the optimum temperature for water absorption by plants, we can follow these steps:

### Step-by-Step Solution:

1. **Understanding Water Absorption**: Water absorption in plants primarily occurs through the root hairs. The efficiency of this process is influenced by temperature.

2. **Identifying Temperature Ranges**: The question provides several temperature ranges:
- 0 to 5 degrees Celsius
- 5 to 20 degrees Celsius
- 20 to 25 degrees Celsius
- 40 to 50 degrees Celsius

3. **Effects of Low Temperatures**: At low temperatures (below 20 degrees Celsius), the permeability of the cell membranes decreases. This results in reduced metabolic activities of the root cells, which negatively impacts water absorption.

4. **Effects of High Temperatures**: At temperatures above 30 degrees Celsius, water absorption also decreases. High temperatures can lead to increased evaporation and stress on the plant, further hindering the absorption process.

5. **Determining the Optimum Range**: Based on the information that temperatures around 30 degrees Celsius favor water absorption, we look for the closest range provided in the options. The range of 20 to 25 degrees Celsius is the most suitable as it is near the optimal temperature for maximum water absorption.

6. **Conclusion**: Therefore, the optimum temperature for water absorption by plants is between **20 degrees Celsius to 25 degrees Celsius**.

### Final Answer:
The optimum temperature for water absorption by plants is **20 degrees Celsius to 25 degrees Celsius**.

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