For cryopreservation, plant materials are frozen at

Options

A. `-196^(@) C`
B. `-150^(@) C`
C. `-80^(@) C`
D. `-40^(@) C`

Answer

**Step-by-Step Solution:**

1. **Understanding Cryopreservation**: Cryopreservation is a technique used to preserve biological samples at very low temperatures. This process is essential for maintaining the viability of cells, tissues, and other biological constructs.

2. **Purpose of Cryopreservation**: The primary goal of cryopreservation is to prevent unregulated chemical reactions that can lead to the degradation of biological materials. By freezing these materials, their metabolic activities are halted, thus preserving their integrity.

3. **Identifying the Freezing Temperature**: In cryopreservation, different temperatures can be used, but specific temperatures are more commonly associated with the preservation of plant materials.

4. **Analyzing the Options**: The options provided are:
- A) -196 degrees Celsius
- B) -150 degrees Celsius
- C) -80 degrees Celsius
- D) -40 degrees Celsius

5. **Evaluating Each Option**:
- **Option A (-196 degrees Celsius)**: This temperature is associated with the use of liquid nitrogen, which is commonly used for cryopreservation of plant materials. This is the correct answer.
- **Option B (-150 degrees Celsius)**: This temperature is not typically used for cryopreservation.
- **Option C (-80 degrees Celsius)**: While this temperature can be used for cryopreservation, it is not the standard for plant materials.
- **Option D (-40 degrees Celsius)**: This temperature is also not suitable for cryopreservation.

6. **Conclusion**: Based on the analysis, the correct answer for the freezing temperature for cryopreservation of plant materials is **-196 degrees Celsius**.

**Final Answer**: A) -196 degrees Celsius

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