Question

Two cross-sections of stem and root appear similar, when viewed by naked eye, but under microscope, they can be differentiated by

• A. Exarch condition of root and stem
• B. Endarch condition of stem and root
• C. Endarch condition of root and exarch condition stem
• D. Endarch condition of stem and exarch condition of root

Answer 1

Answer: (D)

Endarch condition of stem and exarch condition of root

The xylem and phloem together form the vascular bundles. These are variously arranged in different plants.

Endarch is the arrangement in which the protoxylem is directed towards the centre and metaxylem elements towards the periphery. The development of the xylems in this arrangement follows the centrifugal pattern. It is the characteristics of the stem of flowering plants. Whereas exarch is the arrangement in which the protoxylem is directed towards the periphery and metaxylem towards the centre. The development of the xylem in this arrangement follows the centripetal pattern. It is the characteristics of roots. So, two cross-sections of stem and root appear similar, when viewed by naked eye, but under a microscope, they can be differentiated by endarch condition of stem and exarch condition of the root.

Therefore, the correct answer is option D.