In `C_4` - plants , the decarboxylation of `C_4` acid to produce `C_3` acid and `CO_2` during photosynthesis occurs in -

Options

A. mesophyll
B. stroma
C. bundle sheath
D. grana

Answer

To solve the question, we need to identify where the decarboxylation of C4 acid to produce C3 acid and CO2 occurs in C4 plants during photosynthesis.

### Step-by-Step Solution:

1. **Understand C4 Photosynthesis**:
- C4 plants have a unique photosynthetic pathway that involves the fixation of carbon dioxide into a 4-carbon compound (C4 acid) in the mesophyll cells.

2. **Identify the Cells Involved**:
- In C4 plants, the initial fixation of CO2 occurs in the mesophyll cells, where phosphoenolpyruvate (PEP) combines with CO2 to form C4 acid.

3. **Transport of C4 Acid**:
- The C4 acid (such as oxaloacetate) is then transported from the mesophyll cells to the bundle sheath cells.

4. **Decarboxylation Process**:
- In the bundle sheath cells, the C4 acid undergoes decarboxylation. This means that the C4 acid loses a carbon atom in the form of CO2, resulting in the formation of a 3-carbon compound (C3 acid).

5. **Conclusion**:
- Therefore, the decarboxylation of C4 acid to produce C3 acid and CO2 occurs specifically in the **bundle sheath cells**.

### Final Answer:
The decarboxylation of C4 acid to produce C3 acid and CO2 during photosynthesis occurs in **bundle sheath cells**.

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