How are the three main organs of seed plants similar in structure

Following characteristics show that three main organs of a plant are root, stem and leaves are similar in structure.

Roots structure: A root structure shows that it is made up of meristem cells, epidermal cells, xylem and phloem cells and ground tissues. Meristem cells increase the primary growth and epidermal cells increase the surface area of a root

Stem structure: A stem structure shows that it consists of meristem tissues, epidermal tissues, vascular bundles (xylem and phloem) and ground tissues.

Leaf structure: A leaf is made up of epidermal cells, a waxy layer called as the waxy cuticle.