The Casparian Strip Prevents Water from Diffusing Through the ____

Question

The Casparian strip prevents water from diffusing through the ____.  
A) epidermis
B) vascular tissue
C) cortex
D) cytoplasm of endodermal cells
E) endodermal cell walls

Accepted Answer

The Casparian strip is a band of cell wall material found in the endodermal cells of plant roots. It is impregnated with suberin, a waxy substance that prevents water from diffusing through the cell walls of the endodermis, thus forcing water to enter the cells (and therefore the vascular tissue) via a more controlled pathway. This ensures that the plant can regulate the uptake of water and dissolved nutrients.