With reference to factors affecting the rate of photosynthesis, which of the following statements is not correct ?

Options

A. Light saturation for `CO_(2)`-fixation occurs at 10% of fun suniight
B. Increasing atmospheric `CO_(2)` concentration upto 0.05% can enhance `CO_(2)`-fixation rate
C. `C_(3)` plants respond to higher temperature with enhanced photosyntheis. white `C_(4)` plants have much tower temperature optimum
D. Tomato ts a greenhouse crop, which can be grown in `CO_(2)`-enhanced atmosphere for higher yield

Answer

C

Explanation

In `C_(4)`-plants, the initial fixation of `CO_(2)` occurs in mesophyll cells. The primary acceptor of `CO_(2)` is Phosphoenol Pyruvate (PEP). It combines with `CO_(2)` in the presonce of enzyme PEP carboxylase to form the first stable product, i.e. oxaloacetic Acid (OAA). `C_(3)` plants lack `"PEP"_("caboxylase")` enzyme. They posses RuBisCO enzyme. This enzyme can work as both carboxylase (fixation of `CO_(2)`) and oxygenase (fixation of `O_(2)`). RuBisCO has a much greater affinity for `CO_(2)` than for `O_(2)` and the binding is competitive. At higher temperature, its affinity for `CO_(2)` decrease and it works as oxygenase.
Therefore, at higher temperature photosynthesis decrease in `C_(3)`-plants, while in `C_(4)`-plants it increases.