Medullary Rays in Dicot Stems — NEET Biology
✅ Asked in NEET 2021Select the correct pair. [NEET 2021
Select the correct pair. [NEET 2021
Answer & NCERT explanation
Correct answer: D — Cells of medullary rays that form part of a cambial ring – Interfascicular cambium
Interfascicular cambium is formed by medullary ray cells that become meristematic and join with fascicular cambium to form complete cambial ring. Other options are incorrect - bundle sheath isn't conjunctive tissue, lenticels aren't spongy parenchyma, bulliform cells aren't subsidiary cells. NCERT explains cambium formation.
Read more NCERT concept on the PYQ
In between the vascular bundles there are a few layers of radially placed parenchymatous cells, which constitute medullary rays. A large number of vascular bundles are arranged in a ring; the 'ring' arrangement of vascular bundles is a characteristic of dicot stem. Each vascular bundle is conjoint, open, and with endarch protoxylem. A large number of rounded, parenchymatous cells with large intercellular spaces which occupy the central portion of the stem constitute the pith.
Medullary rays are radially arranged parenchymatous cells that lie between vascular bundles in dicot stems, extending from the pith toward the cortex. NTA tests this because students often confuse medullary rays with other tissues like phloem rays or mistake their function. The key trap: thinking medullary rays are the same in monocots—they're actually a characteristic feature of dicots only. Remember that medullary rays provide lateral transport of nutrients and water, and their radial arrangement is diagnostic of dicot anatomy. When identifying dicot cross-sections, spot the ring arrangement of vascular bundles first, then identify the parenchymatous rays filling the spaces between them.
What does NCERT say about between vascular bundles there?
Has this concept appeared in NEET?
Which chapter is this from?
Through deep analysis of NEET and NTA, 176 of the 180 ReNEET 2026 (June 21) questions were already in the MedicNEET question bank before the exam.
176/180MedicNEET's Biology question bank is built from the same NCERT lines NTA picks repeatedly. Not random MCQs — questions crafted exactly like NTA crafts them.
You just learned this concept. The free app turns it into a daily goal built from your weak topics and brings it back just before you forget it — using active recall and spaced repetition — so it stays till exam day.