Back to your test review
Start free test
During photorespiration, the oxygen-consuming reactions occur in the
Your answer:
Correct answer: (c)
Advertisement
Explanation
Why (c) is correct
In photorespiration, RuBisCO works as an oxygenase in the chloroplast stroma: RuBP takes up O2 and splits into one PGA and one phosphoglycolate. The glycolate made from it moves to the peroxisome, where it is oxidised using O2 again. So oxygen is consumed in two places: the chloroplast stroma and the peroxisome.
Why the other options are wrong
- (a) · your answer Mitochondria are part of the pathway, but there glycine is converted to serine and CO2 is released. No O2 is taken up in this step.
- (b) · your answer This misses the peroxisome, the second place where O2 is used.
- (d) · your answer The grana (thylakoids) carry out the light reaction. RuBisCO works in the stroma, not the grana.
NCERT point: Photorespiration makes neither sugar nor ATP. It uses up ATP and releases CO2. C4 plants avoid it by keeping the CO2 level high around RuBisCO.
Thank you! We will check this question.
Practise Photosynthesis in Higher Plants
Take a free 15-question NEET Biology test on this chapter. Timed, scored instantly.