Root hair cells and the pathway of waterSpec B8.2.1, B8.2.2, B8.2.3
In short
A root hair cell is a cell in the outer layer of the root with a long, thin extension that absorbs water and mineral ions from the soil. The root hair gives a large surface area, which increases uptake. Water then passes through the root cortex cells, into the xylem, and up to the mesophyll cells of the leaf.
Root hair cells
A root hair cell is a cell in the outer layer of the root that has a long, thin extension called the root hair. Its functions are to absorb water from the soil and to absorb mineral ions from the soil.
Supplement (what this means)
Supplement: only for the Extended papers (2 and 4). Core students can skip it. What the labels meanThe root hair gives the cell a large surface area, which increases the uptake of water and mineral ions.
(opens full size in a new tab)The pathway of water
Water takes the same route from the soil to the air. You need to be able to outline it.
- Water enters the root hair cells from the soil.
- It passes through the root cortex cells.
- It enters the xylem and moves up the root and stem.
- It leaves the xylem in the leaf and reaches the mesophyll cells.
(opens full size in a new tab)Give the cells in the right order: root hair cells, root cortex cells, xylem, mesophyll cells. Writing 'roots to leaves' alone will not score.
Quick check
What do root hair cells absorb?
Show answer
Water and mineral ions.
Supplement Why does a root hair increase uptake?
Show answer
It gives the cell a large surface area.
Give the pathway of water in order.
Show answer
Root hair cells, root cortex cells, xylem, mesophyll cells.
Written and checked against the Cambridge IGCSE Combined Science (0653) specification · Updated October 2026