Question

Why does apoplast pathway occur in root cortex but not in endodermis?

Answer 1

Because of the casparian strip in endodermis

Answer 2

The apoplast pathway occur in cortex, until it reaches the endodermis because at the endodermis, the cellulosic cell wall of the cells of the endodermis have a band of suberised matrix called casparian strip, which is impermeable and prevents the movement of water.