Question

In $C_4$ plants, Calvin cycle enzymes are present in _______ .

• A. Chloroplasts of chlorophyll cells
• B. Chloroplasts of bundle sheath cells
• C. Cytoplasm of guard cells
• D. Cytoplasm of epidermal cells

Answer 1

Answer: (B)

Chloroplasts of bundle sheath cells

$C_4$ pathway occurs in plants growing in adverse environmental conditions. Therefore, to efficiently fix $C{O}_2$ and prevent photorespiration, fixation occurs in two morphologically and chemically different cells; the bundle sheath and the mesophyll cells. Initially $C{O}_2$ from the atmosphere is accepted by PhosphoEnolPyruvic acid to form OxaloAceticAcid in the mesophyll cells surrounding the bundle sheath as a ring (Kranz) and then OAA is transported to the bundle sheath cells for decarboxylation and fixation by RuBisCO.

So, the correct answer is 'Chloroplasts of bundle sheath cells'