Assertion: Under conditions of high light intensity and limited CO2 supply,
photorespiration has a useful role in protecting the plants from photo-oxidative damage.
Reason: If enough CO2 is not available to utilize light energy for carboxylation to proceed, the excess energy may not cause damage to plants.
If both assertion and reason are true and reason is the correct explanation of assertion
If both assertion and reason are true but reason is not the correct explanation of assertion
If assertion is true but reason is false
If both assertion and reason are false.
C.
If assertion is true but reason is false
Photorespiration protects the plants from photoxidative damage by dissipating excess of excitation energy. When the CO2 supply is limited and under high light intensity photorespiration takes place thus protecting the plants. If enough CO2 is not available to utilize light energy for carboxylation to proceed, the excess energy will cause photoxidative damage to the plants. The energy liberated should be used in photophosphorylation in presence of CO2. If CO2 is less then in C3 plants O2 combines with RuBP to form phosphoglycollatc thus utilizing the excess energy.
