Water Uptake
Biology: Cambridge International GCSE Supplement, topic 8.2.1
Water Pathway
Water moves into the plant in the roots, then moves up through the plant:
Root hair cell
- First, water osmoses into root hair cells.
- These are specialised cells on roots that have projections, creating a large surface area for osmosis.
Root cortex cells
- Water then moves into the root cortex cells.
Xylem vessels
- Xylem vessels collect water from the root cortex and transport it up the plant's stem.
Mesophyll cells
- When it reaches a leaf, water osmoses out of the xylem into the leaf's mesophyll cells.
Investigating the pathway
- By putting a wilting celery stalk in water that contains a stain such as blue food dye, it is possible to watch the blue water travelling up the celery stem and to the leaves.
Test yourself on Water Uptake
Water Pathway
A gardener trims off all the root hairs from a plant's roots. What is the most likely effect on the plant's water uptake?
By what process does water enter root hair cells?