Question

Which one of the pathways of water movement involves cell wall and intercellular spaces ?

• A. Vacuolar pathway
• B. Protoplast pathway
• C. Symplast pathway
• D. Apoplast pathway

Answer 1

Answer: (D)

Apoplast pathway

Answer 2

The concept of apoplast and symplast was introduced by Munch in 1930. In apopiast pathway, "water passes . from root hairs to xylem through the walls of intervening cells, without crossing any membrane or cytoplasm. It provides the least resistance to movement of water. It is interrupted by the preserice of impermeable lignosube1in Casparian strips in the walls of endodermal cells. In symplast pathway, water passess from cell to cell through their protoplasm facing plasmalemma (cell membrane), at least at one place. It is also called transmembrane pathway. It does not enter cell vacuoles. The cytoplasm of the adjacent cells are connected through bridges called plasmodesmata. Symplastic movement is aided by cytoplasmlc streaming of individual cells. It is, however, slower than apoplastic movements.