Question

In $C_4$ plants, the final fixation of $C{O}_2$ takes place at

• A. Mesophyll cell's chloroplast
• B. Bundle sheath cell's cytoplasm
• C. Mesophyll cell's cytoplasm
• D. Bundle sheath cell's chloroplast

Answer 1

The correct option is D Bundle sheath cell's chloroplast

After carbon fixation, the OAA produced is transported from the cytosol of mesophyll cells to chloroplasts of bundle-sheath cells. Here, decarboxylation of OAA takes place and it releases pyruvic acid and fixed CO${}_2$. The pyruvic acid is transported back to mesophyll whereas the CO${}_2$ enters the Calvin cycle.

So, the correct option is 'Bundle sheath cell's chloroplast'.