You are given a fairly old piece of dicot stem and a dicot root. Which of the following anatomical structures will you use to distinguish between the two.
The anatomy of dicot root and dicot stem differ in many characters. In dicot, root epidermis contains root hairs, whereas in epidermis contains trichomes, cuticle and stomata. In dicot, root cortex shows general cortex and endodermis, whereas in dicot stem cortex shows hypodermis, general cortex and endodermis.
In dicot, root hypodermis is absent whereas, in dicot stem, hypodermis is present.
In dicot root endodermis shows Casparian bands, whereas in dicot stem endodermis contains starch grains in its cells.
In dicot root pericycle is parenchymatous, take part in the lateral formation and secondary growth, whereas in dicot stem, pericycle is discontinuous, sclerenchymatous, present in the form of patches over the vascular bundles.
In dicot root, vascular bundles are radial, whereas in dicot stem vascular bundles are collateral, conjoint, open
In dicot, root xylem is exarch, whereas in dicot stem xylem is endarch.
In dicot, root medulla is reduced, whereas in dicot stem is xylem is endarch.
In dicot root, conjunctive tissue is present, whereas, in dicot stem, medullary rays are present.
So, the correct option is ‘Protoxylem’