In the process of photosynthesis, sugar molecules are built during the dark reactions, also known as the Calvin cycle. This cycle takes place in the stroma of the chloroplasts. During the light-dependent reactions, the energy from sunlight is used to produce ATP and NADPH, which are then utilized in the Calvin cycle to convert carbon dioxide into glucose (sugar).
1) Sugar molecules are built in the dark reactions (Calvin cycle).
2) The dark reactions occur in the stroma of the chloroplasts.
Therefore, the correct answer to the question is:
2) in the dark reactions