Question Detail
Question
O2 produced by photosynthesis is from
Correct Answer
Option A is the correct answer.
Detailed Explanation
The oxygen released during photosynthesis comes from the splitting of water molecules (photolysis). This was demonstrated by experiments using isotopically labeled oxygen (18O) in water. CO2 provides the carbon and some oxygen for the sugar, but not the O2 gas.
Hint
Which molecule is split to release oxygen in the light reactions?