which out of the following statements is incorrect ?

Options

A. The breakdown product of glucose which enters into mitochondrion during aerobic respiration is pyruvic acid generated in the cytosol.
B. When the electrons pass from one carrier to another via complex I to IV in the electron transport chain, they are coupled to ATP synthase (complex V) for the production of ATP from ADP and Pi
C. The ratio of volume of `O_(2)` consumed in respiration to the volume of `CO_(2)` evolved is called as the respiratory quotient `(RQ)`.
D. Compensation point is the point reached in a plant when the rate of photosynthesis is equal to the rate of respiration.

Answer

To determine which statement is incorrect, we will analyze each statement one by one.

### Step-by-Step Solution:

1. **Analyze the First Statement:**
- The statement claims that the breakdown product of glucose that enters the mitochondria during aerobic respiration is pyruvic acid generated in the cytosol.
- **Explanation:** During glycolysis, which occurs in the cytosol, one molecule of glucose is converted into two molecules of pyruvic acid. This pyruvic acid then enters the mitochondria for further processing in aerobic respiration.
- **Conclusion:** This statement is correct.

2. **Analyze the Second Statement:**
- The statement mentions that when electrons pass from one carrier to another via complexes 1 to 4 in the electron transport chain, they are coupled to ATP synthase (complex 5) for the production of ATP from ADP and inorganic phosphate (Pi).
- **Explanation:** This accurately describes the process of oxidative phosphorylation, where the electron transport chain creates a proton gradient that drives ATP synthesis via ATP synthase.
- **Conclusion:** This statement is also correct.

3. **Analyze the Third Statement:**
- The statement defines the ratio of the volume of O2 consumed in respiration to the volume of CO2 evolved as the respiratory quotient.
- **Explanation:** The correct definition of the respiratory quotient (RQ) is the volume of CO2 produced divided by the volume of O2 consumed (RQ = CO2/O2). The statement incorrectly reverses this ratio.
- **Conclusion:** This statement is incorrect.

### Final Conclusion:
The incorrect statement is the third one, which misdefines the respiratory quotient.

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