Question

The conduction of water from root hair to root xylem is ?

• A. Symplastic
• B. Apoplastic
• C. Osmotically
• D. Symplastic and apoplastic

Answer 1

The correct option is D Symplastic and apoplastic

Apoplast refers to the dead non-living part of plant. It comprises of the intercellular spaces and cell walls. Symplast refers to the living part of plant. It comprises of the plasma membrane and protoplasm. Transport through apoplast is fast as water is not required to cross the plant cell. Movement of water from root hair to root xylem is through both apoplast and symplast.

As root hairs come in contact with water, they automatically absorb water in apoplast. This is a physical process just like water is soaked up by a piece of paper or cotton. Like that water reaches upto the layer of endodermis. The endodermal cells have casparian strips, which makes it impossible for water to move further through apoplastic pathway. At the endodermis, water passes through symplast. Once endodermis is crossed, water again is free to follow apoplast or symplast pathway, till it reaches xylem.

So, the correct answer is 'Symplastic and apoplastic'