Which of the following options does not hold good regarding anaerobic respiration or fermentation ?

Options

A. Occurs inside the mitochondria
B. Partial breakdown of glycose occurs
C. Net gain of only 2 ATP molecules
D. None of these

Explanation

To solve the question "Which of the following options does not hold good regarding anaerobic respiration or fermentation?", we will analyze each option provided.

### Step-by-Step Solution:

1. **Understanding Anaerobic Respiration**:
- Anaerobic respiration occurs in the absence of oxygen. It involves the breakdown of glucose to produce energy, using other molecules as the final electron acceptor.

2. **Analyzing the Options**:
- **Option A: Occur inside the mitochondria**:
- This statement is incorrect for anaerobic respiration. Anaerobic respiration, including fermentation, occurs in the cytoplasm of the cell, not in the mitochondria. Mitochondria are involved in aerobic respiration.
- **Option B: Partial breakdown of glucose occurs**:
- This statement is correct. Anaerobic respiration involves the partial breakdown of glucose, resulting in products like ethanol or lactic acid.
- **Option C: Net gain of only two ATP molecules**:
- This statement is also correct. During anaerobic respiration, specifically fermentation, there is a net gain of only two ATP molecules per glucose molecule.
- **Option D: None of these**:
- This option suggests that all previous statements are correct, which is not true since Option A is incorrect.

3. **Conclusion**:
- The option that does not hold good regarding anaerobic respiration or fermentation is **Option A: Occur inside the mitochondria**.

### Final Answer:
**Option A: Occur inside the mitochondria** does not hold good regarding anaerobic respiration or fermentation.

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