Question

What do you understand by the term Dimorphic chloroplast?

Answer 1

Dimporphic chloroplasts are the chloroplasts that have different structure and size i.e one is large and other one is small. It is present in C4 plants. These plants have special type of anatomy known as Kranz anatomy in which vascular bundles are surrounded by large cells known as  bundle sheath cells. These bundle sheath cells contain chloroplast that lack grana whereas adjacent mesophyll cells possess abundant of grana. This presence of dimorphic chloroplast contribute in greater productivity of biomass, prevents photorespiration and increases tolerance of high temperatures in C4 plants.

Answer 2

The outer sheath of cells is known as the mesophyll sheath and it contains chloroplasts similar to those of C3plants in that they have grana. They are, however, different in that they do not normally contain starch grains. Not all C4 plants show such structural dimorphism of their chloroplasts.