What is the definition of suberin and the casparian stip in roots?

Question

any help will be appreciated

Answer 1

In plant anatomy, the Casparian strip is a band of Cell wall material in the radial and transverse walls of the endodermis, which is chemically different from the rest of the cell wall. It is used to block the passive flow of materials, such as water and solutes into the stele of a plant.