Biology · Anatomy of Flowering Plants · NEET
It lies in the small parenchymatous patches BETWEEN the xylem bundles and the phloem bundles inside the stele. In a root, xylem and phloem sit on separate radii (radial arrangement), so the living parenchyma filling the gaps between them is the conjunctive tissue. For NEET, remember one line: conjunctive tissue = tissue between xylem and phloem.
Between XYLEM and PHLOEM. This is the exact answer NEET tests. Do not confuse it with the pericycle (a layer just inside the endodermis) or pith (the central region). Conjunctive tissue is only the parenchyma wedged between the alternating xylem and phloem strands.
Pith is the central core of the root (often small or absent in dicot roots, large in monocot roots). Conjunctive tissue is the parenchyma between xylem and phloem, not at the centre. Both are living parenchyma, but their positions differ: pith is central, conjunctive tissue is between the vascular strands.
It is LIVING parenchyma with thin cellulose walls. Because it stays living, its cells can become meristematic again. That is why part of the conjunctive tissue turns into vascular cambium during secondary growth in a dicot root.
In a dicot root the vascular cambium is fully secondary in origin. It first appears as strips of conjunctive parenchyma just below (internal to) the phloem bundles. Cells of the pericycle above the protoxylem then join these strips to complete the cambial ring. So conjunctive tissue is the seat where the cambium begins in dicot roots.
Yes. Both dicot and monocot roots have parenchymatous conjunctive tissue between the xylem and phloem. The key difference is that monocot roots usually do NOT show secondary growth, so their conjunctive tissue does not turn into a vascular cambium; it simply remains as filler parenchyma.
Match List-I with List-II: List-I: A. Conjunctive tissue B. Casparian strips C. Subsidiary cells D. Starch sheath List-II: I. Specialised cells in the vicinity of guard cells II. Endodermal cells rich in starch III. Tissue between xylem and phloem IV. Endodermal cells with suberin deposition
In the dicot root the vascular cambium originates from:
Try the real previous-year questions from this chapter — each with the answer and a full solution.
It is the parenchyma tissue lying between the xylem and phloem in a root.
No. Pericycle is a layer just inside the endodermis. Conjunctive tissue is the parenchyma between the xylem and phloem strands. But note: pericycle cells above the protoxylem join the conjunctive tissue to form the cambial ring in dicot roots.
Because part of it becomes the vascular cambium, which starts secondary growth (secondary xylem and phloem, later increasing root thickness).
The term is mainly used for the root, where xylem and phloem are on separate radii. In a stem the xylem and phloem lie together in one bundle (conjoint), so the classic conjunctive tissue between separate patches is a root feature.
