Pathway Taken by Water (Cambridge (CIE) IGCSE Biology): Revision Note

Pathway taken by water

• Water is taken up from the soil into root hair cells

• Water then moves across the root cortex and into the xylem (opens in a new tab) vessels by osmosis

• Water is then transported in the xylem to the leaves where it enters the leaf mesophyll cells

• So the pathway is:

root hair cell → root cortex cells → xylem → leaf mesophyll cells

Investigating water movement in plants

• The pathway taken by water through a plant can be studied using a suitable stain, or dye, as follows:

  • place a plant stem, e.g. celery, into a beaker of water that has had a stain added to it

  • leave for a few hours, or until the leaves of the celery turn the same colour as the dyed water (indicating that the dye has travelled all the way up the xylem)

  • cut a cross-section of the stem and view the position of the coloured dye, which will correspond with the location of the xylem vessels