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): C ₄ plants lack photorespiration and have higher productivity. Reason (R): In C ₄ plants, RuBisCO is located in bundle sheath cells where the continuous decarboxylation of malic acid maintains a high intracellular concentration of CO ₂ . In the light of the above statements, choose the most appropr
Options
- ABoth Assertion (A) and Reason (R) are true but Reason (R) is not the correct explanation of Assertion (A).
- BAssertion (A) is true but Reason (R) is false.
- CAssertion (A) is false but Reason (R) is true.
- DBoth Assertion (A) and Reason (R) are true and Reason (R) is the correct explanation of Assertion (A).
Correct answer
D. Both Assertion (A) and Reason (R) are true and Reason (R) is the correct explanation of Assertion (A).
Step-by-step solution
Assertion (A) is true because C ₄ plants have a mechanism that increases the concentration of CO ₂ at the enzyme site, which prevents RuBisCO from acting as an oxygenase. This lack of photorespiration minimizes carbon loss and leads to higher productivity. Reason (R) is also true and correctly explains the assertion. In C ₄ plants, the initial carbon fixation occurs in mesophyll cells to form a C ₄ acid such as malic acid. This acid is transported to the bundle sheath cells, where it is decarboxylated. The continuo