Question
Biology Question on Anatomy of Flowering Plants
Anatomically fairly old dicotyledonous root is distinguished from the dicotyledonous stem by
A
absence of secondary phloem
B
presence of cortex
C
position of protoxylem
D
absence of secondary xylem
Answer
position of protoxylem
Explanation
Solution
In dicot root the protoxylem is located near the periphery of the vascular cylinder, the metaxylem farther inward. In roots xylem is exarch or centripetal. In dicot stem the protoxylem is located near the centre of vascular bundle and metaxylem is located near the periphery i.e. the xylem is endarch or centrifugal.