NEET BIOLOGY

Detailed explanation-1: -The casparain strip prevents water from entering the pericycle except through the cytoplasm of endodermal cells. Because of the casparian strip, water and minerals cannot cross the endodermis and enter the vascular cylinder via the apoplast.

Detailed explanation-2: -The Casparian strips in the endo-and exodermis of vascular plant roots appear to play an important role in preventing the non-selective apoplastic bypass of salts into the stele along the apoplast under salt stress.

Detailed explanation-3: -Formed in the apoplast, the Casparian strip encircles the endodermis in a strongly hydrophobic band. The strip not only blocks apoplastic flow, but also provides resistance to the negative water pressure in the xylem, and thus the endodermis is often regarded as the root’s inner skin [4, 5, 6].

Detailed explanation-4: -The casparian strip prevents apoplastic movement of water. The casparian strip is made of suberin which is impermeable to water. The only way that water and mineral ions can pass across the endodermis is by the symplast pathway, by crossing the cell membrane and passing through the cytoplasm and into the xylem.