In the leaves of $\mathrm{C}_4$ plants, malic acid formation during $\mathrm{CO}_2$ fixation occurs in the…
In the leaves of $\mathrm{C}_4$ plants, malic acid formation during $\mathrm{CO}_2$ fixation occurs in the cells of:
bundle sheath
phloem
epidermis
mesophyll.
Solution
$\mathrm{C}_4$ plants have Kranz anatomy consisting of mesophyll and bundle sheath cells. In mesophyll cells, PEP functions as $\mathrm{CO}_2$ acceptor and forms oxalic acid. Later, oxalic acid is reduced to malic acid. Finally, malic acid is transferred to bundle sheath cells.