Question

Some vascular bundles are described as open because these

• A. possess conjunctive tissue between xylem and phloem
• B. are not surrounded by pericycle
• C. are surrounded by pericycle but no endodermis
• D. are capable of producing secondary xylem and phloem

Answer 1

The correct option is D are capable of producing secondary xylem and phloem

Open vascular bundles refer to the presence of a strip of cambium in between the xylem and phloem of each vascular bundle. Such types of vascular bundles can be seen in dicotyledonous stems and gymnosperms. Cambium is a secondary meristem. Its presence makes the vascular bundle ‘open’ for secondary growth and, hence, the name.


Conjunctive tissue is found in between the xylem and phloem as patches of parenchymatous cells in dicot roots.

The pericycle is the layer following the endodermis. It is made up of both thick-walled parenchymatous cells and sclerenchyma fibres in a dicot stem.