Book 24, Question 54
What are root hairs, and why do roots have so many?
Root hairs are tiny threadlike growths from a root's outer cells. They look like fuzz and are too small to see easily. Each hair soaks up water and minerals, and together they greatly increase the surface of a root. One plant can have billions.
More fun facts
- Root hairs are tiny outgrowths of the cells on a root's outer skin.
- Most of the water and nutrients a plant takes in enter through its root hairs.
- Most root hairs live only a few days or a few weeks.
- New root hairs keep forming as roots grow through the soil.
- Older parts of a root have no root hairs and cannot soak up water.
- Watering right next to a tree trunk does little good. It works better at the drip line, under the edge of the branches, where root hairs are most plentiful.
Sources: NCSU
Questions kids ask
What protects the tip of a growing root?
A root cap covers the tip and protects the cells inside as the root pushes through the soil.