Question

question 1
1 pts
the free oxygen that we breathe comes from where?
a reaction that takes place in the stroma
splitting water
carbon dioxide
2 of these are correct
light independent reaction (calvin cycle)

Explanation:

During photosynthesis, in the light - dependent reactions (which occur in the thylakoid membranes, not the stroma where the Calvin cycle/light - independent reactions occur), water (\(H_2O\)) is split. The reaction is \(2H_2O
ightarrow O_2 + 4H^{+}+4e^{-}\). Carbon dioxide (\(CO_2\)) is used in the Calvin cycle (light - independent reactions) to produce glucose (\(C_6H_{12}O_6\)) and other organic compounds, not to produce free oxygen.

Answer:

splitting water