Question

Kranz type of leaf anatomy is observed in the

• A. $C_3$ plants.
• B. $C_4$ plants.
• C. $C_3$ and $C_4$ plants.
• D. Hydrophytic plants.

Answer 1

Answer: (B)

$C_4$ plants.

C${}_4$ photosynthesis incorporates novel leaf anatomy, metabolic specializations and modified gene expression. Plants that utilize this pathway typically possess a distinctive Kranz leaf anatomy, consisting of two photosynthetic cell types. Their vascular bundles are surrounded by two rings of cells; the inner ring, called bundle sheath cells and the outer ring, called mesophyll cells. The bundle sheath cells have agranal chloroplast and fix carbon dioxide with the help of RuBisCO enzyme. The thin walled mesophyll cells carry out initial carbon dioxide fixation with the help of PEP carboxylase enzyme. This special arrangement of cells and presence of dimorphic chloroplasts helps in minimizing photorespiration in C${}_4$.

Thus, the correct answer is option B.