OBJECTIVE FORESTRY

Detailed explanation-1: -Contrary to dicots, monocotyledonous plants’ vascular bundles do not have a layer of meristematic tissue (cambium). Thus, the vascular bundles of monocots are said to be closed since no new cells can grow inside of them, whereas the vascular bundles of dicot plants can.

Detailed explanation-2: -However, secondary growth from vascular cambium is completely absent in the monocot lineage, likely due to a loss of one or multiple crucial genes required for vascular cambium identity, patterning, differentiation, or development early in their evolutionary history.

Detailed explanation-3: -Secondary growth does not occur in monocots as their vascular bundles are closed and they lack cambium. Cambium is the only meristematic tissue in the stem and the root that can trigger the secondary growth.

Detailed explanation-4: -In the monocotyledons, the vascular bundles have no cambium present in them.