[A]: `C_4` pathway is more efficient that n `C_3` pathway.
[R]: Photorespiration is suppressed in `C_4` plants

Options

A. If both Assertion & Reason are true and the reason is the correct explanation of the assertion, then mark a
B. lf both Assertion & Reason are true but the reason is no t the correct explanation of the assertion, then mark b
C. If Assertion is true statement but Reason is false, then mark c
D. If both Assertion and Reason are false statements, then mark d.

Answer

A

Explanation

`C_(4)` photosynthetic pathway is more efficient than `C_(3)` pathway as `C_(4)` plants can pick up `CO_(2)` even when it is found in low concentration. PEP encymes shows high affinity for `CO_(2) cdot C_(4)` plants contain two types of chloroplast (Kranz anatomy) : bundle sheath chloroplast and mesophyll chlroplast. Bundle sheath cells contain Calyin cycle enzymes. Due to high concentraton of `CO_(2)` in bundle sheath cells, RuBP carboxylase works only for Calvin cycle and not fof photorespiration.
Photorespiration is a wasteful process as it works to undo the act of photosynthesis in `C_(3)` plants. No energy rich compound is produced in this process. When temperature increase more and more photosynthetically fixed carbon is lost by photorespiration thus reducing the efficiency of `C_(3)` plants.