NEET2026BiologyChapterActual
Given below are two statements: one is labelled as Assertion (A) and the other is labelled as Reason (R). Assertion (A): Plants like maize and sugarcane have high biomass productivity and show negligible photorespiration. Reason (R): Decarboxylation of C₄ acids in the bundle sheath cells increases the intracellular concentration of CO₂ , ensuring RuBisCO functions primarily as a carboxylase. In the light of the above
Options
- ABoth (A) and (R) are correct and (R) is the correct explanation of (A)
- BBoth (A) and (R) are correct but (R) is not the correct explanation of (A)
- C(A) is correct but (R) is not correct
- D(A) is not correct but (R) is correct
Correct answer
A. Both (A) and (R) are correct and (R) is the correct explanation of (A)
Step-by-step solution
Maize and sugarcane are C₄ plants. They exhibit high biomass productivity and lack photorespiration. In C₄ plants, the initial CO₂ fixation occurs in the mesophyll cells, forming C₄ acids. These acids are transported to the bundle sheath cells, where they undergo decarboxylation. This process releases CO₂ , significantly increasing its intracellular concentration around the enzyme RuBisCO. The high concentration of CO₂ ensures that RuBisCO functions primarily as a carboxylase, minimizing its oxygenase activity. Thi