NEETBotanyPhotosynthesis in Higher Plants
Given below are two statements: one is labelled as Assertion (A) and the other is labelled as Reason (R). Assertion (A): C₄ plants are more productive than C₃ plants because they lack photorespiration. Reason (R): C₄ plants have a mechanism that increases the concentration of CO₂ at the RuBisCO enzyme site located in their mesophyll cells. In the light of the above statements, choose the most appropriate answer from
Options
- ABoth (A) and (R) are true and (R) is the correct explanation of (A)
- BBoth (A) and (R) are true but (R) is not the correct explanation of (A)
- C(A) is true but (R) is false
- D(A) is false but (R) is true
Correct answer
C. (A) is true but (R) is false
Step-by-step solution
Assertion (A) is true because C₄ plants do not undergo photorespiration, which is a wasteful process. This absence of photorespiration allows them to have higher productivity and better yields compared to C₃ plants. Reason (R) is false because in C₄ plants, the enzyme RuBisCO is absent in the mesophyll cells and is instead located in the bundle sheath cells. The mechanism that increases the intracellular concentration of CO₂ operates in the bundle sheath cells, where C₄ acids are decarboxylated, ensuring RuBisCO fu