Practice free →
HomeNEET UGbiologyPhotosynthesis in Higher Plants › In photosynthesis, the source of O2 released int…

In photosynthesis, the source of O2 released into the atmosphere is:

ACO2 (the carbon dioxide molecule)
BGlucose (from carbon fixation)
CH2O (via photolysis in PS II)
DOzone (O3) in the upper atmosphere
Answer & Solution
Correct answer: C. H2O (via photolysis in PS II)
WATER is split (photolysis) by PSII: 2H2O → 4H+ + O2 + 4e⁻. This is the source of atmospheric O2 (proved by Ruben + Kamen using ¹⁸O isotope). NOT from CO2.
Solve this in the app — NEET UG practice & 24k+ MCQs →
Related questions