Root hairA long, thin outgrowth of a single epidermal cell. Root hairs give the root many times more surface for taking in water and minerals.
Cell wallA thin wall of cellulose. Water passes through it easily, and soil particles cling to its outer surface.
Cell membraneThe thin membrane at the edge of the cytoplasm. It is pressed against the inside of the wall. Water crosses it by osmosis. Many dissolved substances cannot cross it freely.
CytoplasmSpread out as a thin lining against the wall, round the vacuole. The nucleus lies in it.
NucleusThe cell's nucleus, in the lining of cytoplasm. A root hair cell has a nucleus but no chloroplasts, because it does not carry out photosynthesis.
VacuoleOne large vacuole filled with cell sap. The sap is a stronger solution than the soil water, so water is drawn into the cell by osmosis.
In the soil 5
Epidermal cellA cell of the epidermis, the outer layer of the root. Every root hair is an outgrowth of one epidermal cell.
CortexThe broad band of cells just under the epidermis. It carries the water and minerals taken in by the root hairs on toward the middle of the root.
Soil particleRoot hairs push round the soil particles and flatten against them. They cling so closely that the particles cannot be rinsed off.
Water filmA thin film of water surrounds each soil particle. This is the water the root hairs take in.
Air spaceIn good soil the gaps between the particles are filled with air. Living roots need it for respiration.
How this list was compiled: Every name was checked on 2026-09-30 in two places, for facts only and with nothing copied. (1) J. N. Martin, Botany for Agricultural Students (1919), the chapters on cells and on roots, https://archive.org/details/botanyforagricul00mart (public domain). (2) C. S. Gager, Fundamentals of Botany (1916), the sections on root-hairs, soil and osmosis, https://archive.org/details/fundamentalsofbo00gagerich (public domain). (3) Wikipedia, text only: Root hair, https://en.wikipedia.org/wiki/Root_hair. (4) Florida State University, Molecular Expressions: Plant Cell Structure, https://micro.magnet.fsu.edu/cells/plantcell.html, for the parts every plant cell has. Licence: own work
The drawing: Drawn for this site on 2026-09-30 from plain geometry; nothing traced. Licence: own work
How it works
This root hair cell diagram has two views. The first shows one cell with its long hair. The second shows root hairs pushing between soil particles. Tap a name to read about the part, or press Quiz me.
Read the full guide
What this root cell diagram shows
A root hair cell is an epidermal cell with one long outgrowth, the root hair. Inside are a thin lining of cytoplasm, a nucleus and one large vacuole. It has no chloroplasts, because it does not carry out photosynthesis.
How water gets in
Each soil particle is wrapped in a thin film of water. The hairs press against the particles and take that water in by osmosis, because the cell sap in the vacuole is a stronger solution than the soil water.
Root hairs live only a few days. Old ones die off and new ones form nearer the tip of the root.
Plasma membrane is accepted for cell membrane.
Questions and answers
What is the function of a root hair cell?
To take in water and dissolved minerals from the soil. The long hair gives the root many times more surface in contact with the soil water.
Why does a root hair cell have no chloroplasts?
It does not carry out photosynthesis, so it has none. Its job is taking in water and minerals.
How is a root hair cell adapted to its function?
It has a long, thin hair that reaches between soil particles, a thin wall that water passes through easily, and a large vacuole of cell sap that draws water in by osmosis.
Is a root hair a whole cell?
No. A root hair is an outgrowth of one epidermal cell of the root. The cell and its hair together are called a root hair cell.