The Casparian strip is a specialized structure formed in the endodermal cells of the root.


The Casparian strip is a band-like structure composed of a waterproof material called suberin. It is located in the radial and transverse walls of the endodermal cells in the root. The Casparian strip plays a crucial role in controlling the movement of water and solutes across the root.


The primary function of the Casparian strip is to create a barrier that forces water and solutes to pass through the selectively permeable plasma membrane of the endodermal cells, rather than circumventing them through the apoplastic pathway. This selective permeability allows the plant to regulate the uptake of ions and nutrients, preventing the entry of harmful substances into the vascular tissue.


The Casparian strip is present in the endodermis of the root, which is the innermost layer of the cortex. It is not found in the endodermis of the stem or any other part of the plant. The endodermis is responsible for regulating the movement of water and solutes from the soil into the vascular tissue.


The Casparian strip is formed during cell differentiation in the endodermis. It starts as small patches of suberin in the primary cell wall of the endodermal cells. As the cells mature, the suberin patches grow and fuse together, forming a continuous strip that completely encircles each endodermal cell.


The Casparian strip ensures that water and solutes enter the plant through the symplastic pathway, which involves crossing the plasma membrane of the endodermal cells. This allows the plant to actively control the movement of substances and maintain homeostasis. Without the Casparian strip, substances could freely pass through the apoplastic pathway and potentially harm the plant.

In conclusion, the Casparian strip is found in the endodermis of the root and plays a vital role in regulating the movement of water and solutes into the plant. It is a specialized structure formed during cell differentiation and acts as a barrier to control the entry of substances into the vascular tissue.

According to NCERT both b and c should be correct.