Describe the internal structure of dicot root.

The T.S of the dicot root shows three regions.
I) Epidermis II) Cortex III) Stele
I) Epidermis :
* It is outermost layer.
* Many of the epidermal cells protrude in the form of unicellular root hairs.
II) Cortex :
* It consists of several layers of thin walled parenchyma cells with intercellular spaces.
Endodermis:
* It is the innermost layer of the cortex.
* It comprises a single layer of barrel shaped cells without intercellular spaces.
* The tangential as well as radial walls of the endodermal cells have casparian strips.
* Casparian strips are a deposition of water impermeable, waxy material – suberin in the form strips.
III) Stele :
* All the tissues on the inner side of the endodermis constitute the stele.
* it consists of
a) Pericycle b) Vascular tissues c) Pith d) Conjunctive tissues
a. Pericycle:
* It is present below the endodermis.
* It is a few layers of thick walled parenchymatous cells.
* Initiation of lateral roots and vascular cambium during the secondary growth takes place in these cells.
b. Vascular tissues :
* There are usually two to four xylem and phloem patches.
* During secondary growth, a cambium ring develops between the xylem and phloem.
c. Pith: It is small or inconspicuous.
d. Conjunctive tissue:
* The parenchymatous cells which lie between the xylem and the phloem are called conjunctive tissue.