Plants require water to carry out photosynthesis and other activities . The continuous flow of water in root xylem is due to transpiration pull. The water is lost through the stomata is replaced by xylem vessel . Evaporation of water molecules cells of cells of leaf creates a suction which pulls water from the xylem of roots to leaves.
Thus , transpiration helps in absorption and upward moward movement of water and minerals dissolved in it from roots to learn.
Cells of roots are in close contact with soil and so actively take up ions by diffusion . The ion-concentration inside the root and hence osmotic pressure increases the movement of water from soil into root which occurs continuously.
