Question

Identify the correct pair of statements from the following.
(I) Pericycle of dicot root parenchymatous but sclerenchymatous in mature monocot root.
(II) Pericycle cells of both dicot ancimonocot roots actively divide to produce lateral toots during secondary growth.
(III) All cells of endodermis are passage cells in dicot.
(IV) Xylem always produced in a centripetal manner in the roots of fruit bearing plants.

• A. (III), (IV)
• B. (I), (II)
• C. (I), (IV)
• D. (II), (III)

Answer 1

The correct option is A (III), (IV)

In dicots, the endodermis is developmentally the innermost portion of the cortex and prevents water, and any solutes dissolved in the water, from passing through this layer via the apoplast pathway. However, the passage cells are endodermal cells of older roots.
The pericycle is a cylinder of parenchyma or sclrenchyma cells which lie just inside the endodermis forming the outer most part of stele in all plants.
Xylem which transports water and nutrients from the roots to the shoot and leaves. In the xylem, the protoxylem and metaxylem vessels exhibit characteristic orientation with reference to the central axis and based on this its differentiated as centripetal and centrifugal. The centripetal arrangement is found in roots of fruit bearing plants where the younger metaxylem vessels are found towards the pith while the older protoxylem vessels are found away from the pith.