In `C_4` pathway regeneration of PEP occurs in

Options

A. Epidermal cells of leaves
B. Cytososl of bundle sheath cells
C. Chloroplast of mesophyll cells
D. Chloroplast of bundle sheath cells .

Answer

### Step-by-Step Text Solution:

1. **Understanding the C4 Pathway**: The C4 pathway is a photosynthetic process that enhances the efficiency of carbon fixation in plants, particularly in hot and dry environments.

2. **Identifying the Key Components**: In the C4 pathway, two main types of cells are involved: mesophyll cells and bundle sheath cells. Each type of cell contains chloroplasts that play distinct roles in the photosynthetic process.

3. **Role of Mesophyll Cells**: In the mesophyll cells, the enzyme PEP carboxylase is responsible for the initial fixation of carbon dioxide. This process leads to the formation of a four-carbon compound.

4. **Role of Bundle Sheath Cells**: The bundle sheath cells contain chloroplasts where the enzyme ribulose bisphosphate carboxylase/oxygenase (rubisco) is used to initiate the Calvin cycle, which ultimately leads to the regeneration of ribulose bisphosphate (RuBP).

5. **Regeneration of PEP**: The question specifically asks about the regeneration of phosphoenolpyruvate (PEP). This regeneration occurs in the mesophyll cells, where PEP carboxylase operates.

6. **Conclusion**: Based on the understanding of the roles of mesophyll and bundle sheath cells in the C4 pathway, we conclude that the regeneration of PEP occurs in the chloroplasts of mesophyll cells.

7. **Final Answer**: Therefore, the correct answer to the question is option 3: chloroplasts of mesophyll cells.