In opuntia, in night the R.Q. will be

Options

A. One
B. More than one
C. Zero
D. Mitochondria.

Answer

To determine the respiratory quotient (R.Q.) of Opuntia during the night, we can follow these steps:

### Step-by-Step Solution:

1. **Understand the Concept of R.Q.**:
- The respiratory quotient (R.Q.) is defined as the ratio of the volume of carbon dioxide produced to the volume of oxygen consumed during respiration.
- Mathematically, R.Q. = CO2 produced / O2 consumed.

2. **Identify the Type of Plant**:
- Opuntia is a type of succulent plant, which means it has adaptations for water conservation. These plants often utilize a different form of photosynthesis known as CAM (Crassulacean Acid Metabolism).

3. **Consider the Process During Night**:
- During the night, succulents like Opuntia do not perform photosynthesis because there is no sunlight. Instead, they rely on respiration.
- In the case of Opuntia, respiration during the night leads to incomplete oxidation of carbohydrates.

4. **Analyze Gas Exchange**:
- Since there is incomplete oxidation of carbohydrates during the night, Opuntia does not consume oxygen or produce carbon dioxide in significant amounts.
- Therefore, the amount of CO2 produced is negligible, and the amount of O2 consumed is also negligible.

5. **Determine the R.Q. Value**:
- Given that both CO2 production and O2 consumption are negligible, the R.Q. approaches 0.
- Thus, for Opuntia during the night, the R.Q. is 0.

6. **Select the Correct Option**:
- Among the options provided (1, more than 1, 0, or Mitochondria), the correct answer is 0.

### Final Answer:
The R.Q. of Opuntia during the night is **0**.

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