|A root only grows near the root tip. The root tip is an
apical meristem covered by a root cap. At the root tip, the apical meristem generates new
cells for both the root cap and the root.
Illustration of a root
|Root Cap: a protective and lubricative cover for the apical meristem of the root.
It is also responsible for gravitropism (growth response to gravity).
As the root tip pushes through soil, the root cap wears away
and new root cap cells are replenished by the apical meristem.
|Zone of elongation: region a few millimeters long where cells produced by the apical meristem elongate.
All root growth occurs here.
|Zone of maturation: also called the root-hair zone, this is
the region where most primary tissue cells mature.
|Root hair: extension of the epidermis (the outmost single-layer of cells)
of young roots. Root hairs greatly increase the absorption area for roots to take in water and minerals. Short-lived; died
root hairs are replaced by new ones as root growing.