Calvin cycle takes place in:

🔑 Key Points
→ Photosynthesis is the process by which carbohydrates are synthesized from inorganic materials like CO2 and H2O with the help of light energy which is trapped by pigments like chlorophyll.
→ Oxygen is produced as a by-product of photosynthesis. It is used up by other organisms like humans for essential metabolic activities.
→ Photosynthesis stages:

Light-dependent reaction or Light reaction: ATP and NADPH2 are formed at the end of the light reaction which then enters the next stage of photosynthesis.
Light-independent reaction or Dark reaction: It is a carbon-fixing stage involving the Calvin cycle, where CO2 from the atmosphere is taken up by the plants and converted into a sugar molecule.
📌 Important Points
→ Depending on the pathways used during the dark reaction, there are the following types of plants:

C3 plants:
C3 plants employ the Calvin cycle for fixing CO2. E.g., Cotton, potato, etc.
C4 plants:
In C4 plants, initial carbon fixation takes place through the HSK pathway in mesophyll cells.
The Calvin cycle takes place in bundle sheath cells.
E.g., Corn, sugarcane, etc.
CAM plants:
Crassulacean Acid Metabolism is used by desert plants for carbon fixation.
Initial fixation of carbon dioxide takes place at night. During the day, CO2 is reduced using the Calvin cycle.
→ Therefore, the Calvin cycle is present in all types of plants.