Question

Anatomically fairly old dicotyledonous root is distinguished from the dicotyledonous stem by

• A. absence of secondary xylem
• B. absence of secondary phloem
• C. presence of cortex
• D. position of protoxylem

Answer 1

The correct option is D

position of protoxylem

Endarch is the arrangement in which the protoxylem is directed towards the centre and metaxylem elements towards the periphery. It is the characteristic of the stem. Whereas exarch is the arrangement in which the protoxylem is directed towards the periphery and metaxylem towards the centre. It is the characteristic of roots.