Which of the following statements is correct with respect to the effect of temperature on rate of respiration ?

Options

A. Rate of respiration increases with an increase in temperature from `0^(@)C` to `30^(@)C`
B. Rate of respiration doubles for every `10^(@)C` rise in temperature, thus temperature co-efficient `(Q_(10))` for respiration is 2.
C. At very high temperatures such as `50^(@)C` or more, rate of respiration decreases due to enzymatic degradation.
D. All of these

Answer

To answer the question regarding the effect of temperature on the rate of respiration in plants, we can break down the explanation into several steps:

### Step-by-Step Solution:

1. **Understanding Respiration in Plants**:
- Respiration is a vital process in plants where they convert glucose and oxygen into energy, releasing carbon dioxide and water as byproducts.

2. **Temperature and Respiration**:
- The rate of respiration is influenced by temperature. Generally, as temperature increases, the rate of respiration also increases. This is because higher temperatures provide more energy to the molecules involved in the respiration process.

3. **Rate of Respiration with Temperature Increase**:
- It is observed that the rate of respiration increases with temperature, particularly from 0 degrees Celsius to around 30 degrees Celsius. This indicates a positive correlation between temperature and respiration rate.

4. **Temperature Coefficient**:
- The temperature coefficient (Q10) for respiration is typically around 2. This means that for every 10 degrees Celsius increase in temperature, the rate of respiration approximately doubles.

5. **Effects of High Temperatures**:
- At very high temperatures (e.g., above 50 degrees Celsius), the rate of respiration can actually decrease. This is due to the denaturation of enzymes that are crucial for the respiration process. Enzymes are proteins that facilitate biochemical reactions, and high temperatures can disrupt their structure, leading to a decrease in their activity.

6. **Evaluating the Statements**:
- **Statement 1**: "Rate of respiration increases with an increase in temperature from 0 degrees Celsius to 30 degrees Celsius" - This is true.
- **Statement 2**: "Rate of respiration doubles for every 10 degrees Celsius rise in temperature" - This is also true.
- **Statement 3**: "At a very high temperature such as 50 degrees or more, rate of respiration decreases due to enzymatic degradation" - This statement is true as well.

7. **Conclusion**:
- Since all the statements regarding the effect of temperature on the rate of respiration are correct, the final answer to the question is "All of the above."

### Final Answer:
The correct answer is: **All of the above**.