What is the physical barrier in the root that regulates the flow of water to xylem via cell walls?

Question

Quizplus · Accepted Answer

The Casparian strip is a layer of specialized cells in the root's endodermis that blocks the movement of water and nutrients through cell walls. It ensures that water and solutes are selectively filtered before they enter the xylem. The epidermis is the outermost layer of cells that protects the root, while phloem is responsible for transporting sugars and other organic compounds throughout the plant. The cortex is the layer of cells between the epidermis and the endodermis that provides support and stores carbohydrates.

What Is the Physical Barrier in the Root That Regulates