2- 60POINTS- Photosynthesis reactions occur in several stages within the chloroplast. The reactions of the Calvin cycle usually do not occur at night, even though they are not directly dependent on light. Select the best explanation for why not.
Carbon dioxide is not available at night.
It is too cold at night for reactions to take place. The Calvin cycle depends on products of light reactions.
Most plants do not make the 4-carbon compounds that would be needed for the Calvin cycle to occur at night.