Why is the Calvin cycle referred fo as a dark reaction?
Because it is a light-independent process
The Calvin cycle is a stage in photosynthesis. Photosynthesis is the process in which plants convert light energy to chemical energy (sugars). There are two stages in photosynthesis:
- Light reaction (the photo part)
- Calvin cycle (the synthesis part)
Only the light reaction directly uses light. The Calvin cycle is fueled by products from the light reaction, but doesn't need light. Therefore it is called the dark reaction.
Note that both stages are interdependent (see image).