Question

The basic difference between stem and root is that
A) Stem is endarch
B) Stem is exarch
C) Stem is mesarch
D) Stem is polyarch

Answer 1

Stem is the portion of the plant above the earth's surface. Root is the plant component that is beneath the soil surface. It comes from the embryo's radical.

Complete answer:
The stem of both dicot and monocot plants has an endarch type of vascular bundle.
The root of both dicot and monocot plants has an exact type of vascular bundle.

Characters	Roots	Stems
Definition	It is the major vegetative organ of the vascular plants, attaching them to the substrate, typically underground	It is the major vegetative organ in the vascular plants, supporting other organs typically above ground
Development	Originates from the radicle	Develops from the vegetative cone
Function	Anchoring of the plant, absorb water from soil, storage of nutrition, vegetative propagation	Mechanical support and appropriate arrangement of branches and leaves, transport of the fluid and nutrient, production of new tissues / organs and unlimited growth
Shape	Spindle shaped, globular, cylindrical, conical etc.	Round, triangular, polygonal, flat and quadrangle
Division	Main, lateral and adventitious roots	Stem, buds and branches
Sections	Root tip with root cap, area of growth, area with root hairs, branching zone	Nodes, internodes, apical and axillary buds
Surface	Exceeds 5-15 times the above ground part of the plant	Significantly less than root’s one
Metamorphoses	Root tubers, photosynthetic roots, aerial roots, stilt roots, contractile roots, bacterial tubers, haustorial roots etc.	Tubers, rhizomes, bulbs, runners, thorns, succulent stems etc.
Formation	It forms root system	It forms crown of the tree
Tropism	Positive hydrotropism, geotropism and negative phototropism	Negative hydrotropism, geotropism and positive phototropism

So, here the correct answer is option A. Stem is endarch.

Note:
Exarch is the protoxylem arrangement aimed at the periphery and metaxylem to the centre. Endarch is the type of protoxylem structure oriented to the middle and the metalaxyl to the periphery. There was a mistake. The roots of most plants are exarchic structures. Protoxylem is the Xylem that was originally developed and grows prior to plant organ development and later metaxylem. Protoxyl is found at the middle under the endarch of the plant stalk and at the end of the organ under metalaxyl.