Question

which cell is responsible for increase in diameter of the stem and root of dicot plants

Answer 1

Merestimatic cells are responsible for increase in diameter of the stem and root of dicot plant....

Answer 2

The answer to this question is lateral meristematic tissue.

Lateral meristems produce tissues that expand the width/circumference of the plant. Cork cambium fundamentally delivers plug while vascular cambium produces auxiliary xylem and optional phloem of the plant.

Lateral, meristems, which are found in every woody plant and in some herbaceous ones, comprise of the vascular cambium and the plug cambium. They deliver optional tissues from a ring of vascular cambium in stems and roots.