Given below are two statements:Statement I : In C_3 plants, some O_2 binds to RuBisCO, hence CO_2 fixation is decreased.Statement II : In C_4 plants, mesophyll cells show very little photorespiration while bundle sheath cells do not show photorespira…

Given below are two statements:

Statement I : In \(C_3\) plants, some \(O_2\) binds to RuBisCO, hence \(CO_2\) fixation is decreased.

Statement II : In \(C_4\) plants, mesophyll cells show very little photorespiration while bundle sheath cells do not show photorespiration.

In the light of the above statements, choose the correct answer from the options given below:

1. Statement I is false but Statement II is true

2. Both Statement I and Statement II are true

3. Both Statement I and Statement II are false

4. Statement I is true but Statement II is false

Doubtly Asked 30 Oct 2026 NEET UG 2024 Practice test neet Save WhatsApp Report

1 answer

Best answer

Answer: 4. Statement I is true but Statement II is false

Key idea: \(O_2\) competes with \(CO_2\) for RuBisCO in \(C_3\) plants, but \(C_4\) plants avoid photorespiration.

Statement I: true. In \(C_3\) plants RuBisCO also binds \(O_2\) (oxygenase activity), which lowers \(CO_2\) fixation.
Statement II: false. In \(C_4\) plants RuBisCO works only in bundle sheath cells, where \(CO_2\) is concentrated, so photorespiration is absent. Mesophyll cells have no RuBisCO-based Calvin cycle, so the statement is not correct as written.

So Statement I is true and Statement II is false.

Doubtly AI · 30 Oct 2026 AI-generated · not yet verified Report

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