Question

Vascular bundles in a dicot stem are considered to be open because:

• A. The cambium is present.
• B. Phloem is surrounded all around by xylem.
• C. There are vessels with perforations.
• D. It is not conjoint.

Answer 1

The correct option is A The cambium is present.

a) The characteristic of the vascular bundles of dicot stem is conjoint, collateral and open. Conjoint collateral and open vascular bundle means the xylem and phloem lie on the same radius and cambium is present between them. The vascular bundles of dicot stem are considered as open due to the presence of cambium. Cambium are the meristematic cells which produce secondary xylem and phloem.

b) Phloem is surrounded by xylem in concentric vascular bundles.

c) Xylem vessels have perforations on their end wall which means they help in water conduction and are not related to open vascular bundles.

d) The vascular bundles of the root are not conjoint as they are radial and do not have the cambium.