Key learning points

1. Plants need water for support (to remain turgid) because they don’t have bones, and for photosynthesis in cells.
2. Plants need mineral ions for growth and repair, including nitrate ions as a source of nitrogen to make proteins.
3. Particles of water are absorbed by osmosis, a type of diffusion, into plant root hair cells.
4. Nitrate ions are absorbed into plant root hair cells by active transport, which requires energy.
5. Root hair cells are adapted to increase the surface area of membrane for osmosis and active transport.

Keywords

• Osmosis - the net movement of water molecules through a selectively-permeable membrane from high to low concentration of water molecules

• Net movement - the overall movement of particles

• Active transport - the net movement of particles against a concentration gradient using energy

• Concentration gradient - a difference in the concentration of particles from one area to another

• Root hair cell - a specialised plant cell found in the roots that absorb water and nutrients into the plant

Common misconception