Question

How plants absorb water from the soil. Explain.

Answer 1

The absorption of water and minerals is more specifically the function of the root hairs that are present in millions at the tips of the roots. Root hairs are thin-walled slender extensions of root epidermal cells that generally increase the surface area for absorption. Water is absorbed along with mineral solutes, by the root hairs, purely by diffusion. Once water is absorbed by the root hairs, it can move deeper into root layers by two distinct pathways:

•apoplast pathway

•symplast pathway

The apoplast is the system of adjacent cell walls that is continued throughout the plant, except at the Casparian strips of the endodermis in the root. The apoplastic movement of water occurs through the intercellular spaces and the walls of the cells. Movement through apoplast does not involve crossing the cell membrane.

The symplastic system is the system of interconnected protoplasts. Neighboring cells are connected through cytoplasmic strands that extend through plasmodesmata. During the symplastic movement, the water travels through the cells-their cytoplasm, the intercellular movement is through the plasmodesmata.