Final answer:
In the dark reaction of photosynthesis, six molecules of carbon dioxide are used to form glucose.
Step-by-step explanation:
In the dark reaction of photosynthesis, also known as the Calvin cycle, six molecules of carbon dioxide (C02) are used. This occurs during the second stage of photosynthesis, where carbon dioxide is reduced to form glucose.
Learn more about the role of carbon dioxide in the dark reaction of photosynthesis