Q. The given figure represents symplastic and apoplastic pathways of water & ion absorption & movement in roots. Few parts are marked as & . At the endodermis, water movement through the apoplast pathway is obstructed by which part (marked as & )? Biology Question Image

 94  177 Transport in Plants Report Error

Solution:

In the given figure which shows the symplastic and apoplastic pathways of water and ion absorption and movement in roots, the structure marked as and are respectively xylem, casparian strip, phloem and cortex. Casparian strip (marked as ), impermeable substances made of suberin and sometimes lignin is a band of cell wall material deposited on the radial and transverse walls of the endodermis. It obstructs the water movement through the apoplastic pathway at the endodermis. It forces water through the endodermal cell and in such a way regulates the amount of water getting to the xylem.