Question

How many type of photosynthetic cells occur in $C_4$ plants?

• A. One type
• B. Two type
• C. Four type
• D. Eight type

Answer 1

The correct option is B Two type

The thick walled bundle sheath cells present around vascular bundles in the shape of a ring in $C_4$ plants have chloroplast. 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 $C_4$ plants. Thus two types of photosynthetic cells occur in $C_4$ plants- one type mesophyll cells, which carry on initial carbon dioxide fixation and another bundle sheath cells, which carry on carbon dioxide fixation using RuBisCO enzyme.