In the dicot root the vascular cambium originates from :-
Answer: (A) Tissue located below the phloem bundles and a portion of pericycle tissue above protoxylem.. Answer: (A) Tissue located below the phloem bundles and a portion of pericycle tissue above protoxylem.
- A.Tissue located below the phloem bundles and a portion of pericycle tissue above protoxylem.✓
- B.Cortical region.
- C.Parenchyma between endodermis and pericycle.
- D.Intrafascicular and interfascicular tissue in a ring.
Correct Answer
(A) Tissue located below the phloem bundles and a portion of pericycle tissue above protoxylem.
Solution & Explanation
Answer: (A) Tissue located below the phloem bundles and a portion of pericycle tissue above protoxylem. Solution: In a dicot root the vascular cambium is completely secondary in origin. It first appears as strips of conjunctive parenchyma lying just below (internal to) the phloem bundles; later the cells of the pericycle situated above (external to) the protoxylem points also become meristematic and join these strips, completing a continuous, initially wavy cambial ring. The pericycle is the seat of initiation of both lateral roots and the vascular cambium during secondary growth. NCERT Reference: NCERT Class XI, Ch 6 Anatomy of Flowering Plants, p.74, line ~13: "Next to endodermis lies a few layers of thick-walled parenchymatous cells referred to as pericycle. Initiation of lateral roots and vascular cambium during the secondary growth takes place in these cells."