Lateral roots originate from this layer.

Lateral roots arise from

The study of the internal structure of plants is called .........

The cross-section of a plant material showed the following features when viewed under the microscope.
$(A)$ The vascular bundles were radially arranged.
$(B)$ Four xylem strands with exarch condition of protoxylem.
To which organ should it be assigned?

What part of the plant would show the following:
$(a)$ Radial vascular bundle
$(b)$ Polyarch xylem
$(c)$ Well developed pith

Describe the internal structure of a dicot root.