The carbon that gets assembled into a sugar molecule in the Calvin cycle comes from:Group of answer choicescarbon dioxide from the atmospherecarbon particles from the soilbreaking down glucosethe roots

The carbon that gets assembled into a sugar molecule in the Calvin cycle comes from carbon dioxide from the atmosphere.

Here's a step-by-step explanation:

1. The Calvin cycle is a part of photosynthesis, the process by which plants convert light energy into chemical energy.

2. In the first stage of photosynthesis, light-dependent reactions capture the energy from light and convert it into ATP and NADPH, which are energy-carrying molecules.

3. In the second stage, the Calvin cycle, these energy-carrying molecules are used to produce glucose from carbon dioxide and water.

4. The carbon dioxide is taken from the atmosphere through the stomata, small openings on the leaves of the plant.

5. Inside the chloroplasts, the site of photosynthesis in the plant cells, the carbon dioxide is combined with a five-carbon sugar called ribulose bisphosphate (RuBP) to form a six-carbon compound.

6. This six-carbon compound is unstable and quickly splits into two three-carbon compounds.

7. These three-carbon compounds are then converted into glucose and other sugars through a series of reactions that also regenerate RuBP, allowing the cycle to continue.

So, the carbon in the sugar molecules produced by the Calvin cycle comes directly from the carbon dioxide in the atmosphere, not from carbon particles in the soil, the breakdown of glucose, or the roots.