Question

Chloroplast dimorphism is a characteristic feature of

• A. Plants with Calvin cycle
• B. $C_4$ plants
• C. All plants
• D. Only in algae.

Answer 1

The correct option is B $C_4$ plants

Dimorphic chloroplasts are the chloroplasts which are concentrated into two types of cells having different size and structure. The dimorphic chloroplast is present in $C_4$ plants because of the presence of special leaf anatomy called Kranz anatomy. They have two types of cells i.e., mesophyll cells and bundle sheath cells, which are required for $C_4$ pathway. The particularly large cells around the vascular bundles of $C_4$ plants are called bundle sheath cells, these cells may form several layers around the vascular bundles, they are characterised by having a large number of dimorphic chloroplasts, grana are absent, thick walls impervious to gaseous exchange and no intercellular spaces. Mesophyll cells have dimorphic chloroplast having grana. Chloroplast dimorphism is characteristic feature of $C_4$ plants, e.g. Amaranthus, Sugarcane, Maize, etc.