Question

By looking at which internal structure of a plant can you tell whether a plant is C3 or C4?

• A. Chloroplast dimorphism
• B. Kranz anatomy
• C. Mesophyll cells only
• D. Both chloroplast dimorphism and Kranz anatomy

Answer 1

The correct option is D Both chloroplast dimorphism and Kranz anatomy

C4 plants possess Kranz type of leaf anatomy. The mesophyll cells occur in concentric layers around vascular bundles. C4 plants possess dimorphic chloroplasts. Chloroplast dimorphism is the condition where mesophyll cells contain chloroplasts with stacked thylakoids while chloroplasts in bundle sheath cells exhibit unstacked thylakoids (lacking grana). While in C3 plants leaf anatomy is not of Kranz type. Only one type of chloroplast is found. Also, mesophyll cells are present in both C3 and C4 plants and hence, it cannot be a differentiating feature.