In an experiment in which photosynthesis is perforemd during the day. You provide a plant with radioactive carbon dioxide `(.^(14)CO_(2))` as a metabolic tracer. The `.^(14)C` is incorporated first into oxaloacetic acid. The plant is best characterised as a

Options

A. `C_(4)` plant
B. `C_(3)` plant
C. CAM plant
D. Insectivorous plant.

Answer

A

Explanation

In `C_(4)` plants, the first stable photosynthetic product is a 4-carbon compound, i.e., oxaloacetic acid (OA A), which is formed by initial fixation of `CO_(2)` by the carboxylation of phosphoenol pyruvate in the mesophyll cells. So, when radioactive `.^(14)O_(2)` is introduced into the reaction, it is first incorporated into the OA A.
`PEP+.^(14)CO_(2)+H_(2)Ooverset("PEP carboxylase")rarrOA A+H_(3)PO_(4)`
In a CAM plant , although the first product formed is OA A, but here the initial `CO_(2)` fixation occurs at night.