How do plants absorb water? Explain .

Explanation

Root hair - water Absorbing Unit :
(I ) There are millions of roots hairs on the tip of the root which absorb water and ninerals by diffusion .
(ii ) Root hairs are thin walled , slender extension of epidermal cell that increase the surface area of absorption .

Pathway of water absorbed by roots :
(i ) Once the water enters the root hairs , the concentration of water molecules in the root hair cells because more than that of the cortex .
(ii ) Thus water from the root hair moves to the cortical cells by osmosis and then reaches the xylem .
(iii ) From there the water is transported to the stem and leaves .

Types of movement of water into the root cells : Once water is absorbed by the root hairs , it can move deeper into root layers by two distinst pathways :
(i ) Apoplast pathway
2. symplast pathway
Apoplast pathway :
(i ) The apoplastic movement of water occurs exclusively through the interceller spaces and the walls of the cells .
(ii ) Apoplasic movement does not involve crossing the cell membrane . this movement is dependent on the gradient .
symplast pathway :
(i ) the water travels through the cells i .e., their cytoplasm , intercellcular movement is through the plasmodesmata .
(ii ) Water enter the cells membrane , hence the movement is relatively slower .
(iii ) Movement is again down a potential gradient .