In C4 plants, Calvin cycle

📌Concept:
C4 plants have a unique mechanism to efficiently fix carbon dioxide (CO2) and minimize photorespiration.
The Calvin cycle is a set of biochemical redox reactions that occur in the stroma of chloroplasts in photosynthetic organisms.
In C4 plants, the Calvin cycle is spatially separated from the initial CO2 fixation.

✅Explanation:
Option 1: occurs in stroma of bundle sheath chloroplasts: This is the correct answer. In C4 plants, the Calvin cycle takes place in the stroma of bundle sheath chloroplasts. This spatial separation allows C4 plants to efficiently fix CO2 and minimize photorespiration.
Option 2: occurs in grana of bundle sheath chloroplasts: This is incorrect. The Calvin cycle does not occur in the grana; it takes place in the stroma. The grana are involved in the light-dependent reactions of photosynthesis.
Option 3: occurs in mesophyll of chloroplasts: This is incorrect. In C4 plants, the initial CO2 fixation occurs in the mesophyll cells, but the Calvin cycle takes place in the bundle sheath cells.
Option 4: does not occur as CO2 is fixed mainly by PEP and no CO2 is left for Calvin cycle: This is incorrect. While it is true that CO2 is initially fixed by phosphoenolpyruvate (PEP) in the mesophyll cells, the CO2 is then transported to the bundle sheath cells where it enters the Calvin cycle.