Which cells in a root form a protective barrier to the vascular system where all materials must move through the symplast?

Question

Quizplus · Accepted Answer

The endodermis forms a protective barrier to the vascular system and controls the movement of materials into the xylem via the casparian strip. This forces all materials to move through the symplast, which is the continuous system of cytoplasmic connections between cells. The pericycle is the outermost layer of the vascular cylinder and gives rise to lateral roots. The cortex is the primary region of storage and parenchyma cells in the root. The epidermis is the outermost layer of cells in the root and functions in water and nutrient uptake.

Which Cells in a Root Form a Protective Barrier to the Vascular