Question

Differentiate between structure of vascular bundles of a dicot stem and a monocot root.

Answer 1

Hint: Dicots have their own vascular bundles in ring arrangement. Monocots have most of their vascular bundles near the outside edge of the stem. Vascular bundle is a part of the transport system in vascular plants. Xylem and phloem are two vascular tissues, both these are present in vascular bundles.

Complete answer:
Difference between structure of vascular bundles of a dicot stem and a monocot root is as follows

Dicot stem

Monocot root

- The vascular system found in dicot stems is arranged in ring form.- In ring form, the pith is not scattered rather it is concentrated at the core of the stem.- In each vascular bundle, the xylem and phloem tissue are separated by vascular cambium.- In dicot stem new vascular bundles are not formed as in monocot stems but the existing bundles grow.- The vascular system in the dicot system is open, collateral and endarch.

- The vascular bundles in the monocot root are polyarch and vascular bundles are 6 in number.- Xylem and phloem bundles are alternate with each other.- In this connective tissue doesn’t form the vascular cambium.- This tissue doesn’t become meristematic.- The vascular system in the monocot root is radial with exarch xylem.

Note: Few differences between monocot and dicot roots are:
- The cortex area is narrow in dicot root and wide in monocot root.
- Older dicot roots have a covering of cork whereas older monocot roots show a covering of exodermis.
- Passage cells are absent in dicot and present in monocot.
- In dicot roots xylem vessels are angular and xylem vessels are oval in monocot.
- Pith is reduced or absent and reduced pith is usually small and at the other hand pith is well developed in monocot roots.