- A A loosely packed waxy band found scattered throughout the entire cortex region of the root in most textbook accounts
- B A waxy band of suberin in the endodermal cell walls that forces water through the symplast pathway
- C A protective lignified layer that encloses and hardens the mature seed coat tissue during normal conditions
- D A corky structure embedded deep within the secondary bark of older woody stems as generally observed
Correct answer: B. A waxy band of suberin in the endodermal cell walls that forces water through the symplast pathway
Explanation: The Casparian strip is a band of suberin (waxy material) in the radial and transverse walls of endodermal cells. It blocks apoplastic (cell wall) water flow, forcing all water through the symplast (via cell membranes), allowing selective mineral absorption.
Concept context
Internal tissue organisation: meristems, permanent tissues (xylem, phloem, parenchyma), and secondary growth. Frequently tested in NEET.