Distinguish between the following:

a. Exarch is a condition where the protoxylem is present towards the periphery and metaxylem is present towards the centre. Endarch is where the protoxylem is present towards the centre and metaxylem is present towards the periphery

b. A stele is the central part of the root or stems whereas a vascular bundle is a part of stele.

c. Earlier formed xylem is called protoxylem and later formed xylem is called metaxylem

d. Interfascicular cambium is present in between the primary xylem and primary phloem whereas intrafascicular cambium is present in between the two vascular bundles making the cambium continuous and forming a complete ring of cambium

e. Open vascular bundles are capable of secondary growth whereas the closed vascular bundles are not capable of secondary growth

f. Stem hair is multicellular and they are epidermal outgrowths known as trichomes whereas root hair is unicellular and they are unicellular elongations of epidermal cells.