Question

Conjoint, collateral, open and endarch vascular bundles are found in
A) Monocot stem
B) Monocot root
C) Dicot root
D) Dicot stem

Answer 1

Vascular bundles form the transport system of a plant. It includes strands of Xylem and Phloem. Conjoint vascular bundles means that the xylem and phloem are arranged together in the same radius.

Complete answer:
Let us analyze the options to find out the correct option.
Option A: The vascular bundles of a monocot stem are in scattered arrangement. Each of them is collateral, conjoint, closed and endarch. The cortex region is surrounded by large parenchyma. Cambium is absent in them. Therefore, this is an incorrect option.

Option B: The vascular bundles in a monocot root are in radial arrangement. Therefore, this is an incorrect option.

Option C: The vascular bundles in the dicot root are in a radial arrangement. The xylem and phloem are arranged separately. Therefore, this is an incorrect option.

Option D: Dicot stems have vascular bundles arranged in a ring. They surround the central pith. Each of the vascular bundles in the dicot stem is collateral, conjoined, open and endarch. A cambium is present between xylem and phloem. Therefore, this is the correct option.

Hence the correct answer is (D) Dicot stem.

Note:
i) The vascular bundles are almost uniform in size in the dicot stem.
ii) The phloem is situated on the periphery of xylem.
iii) Fascicular cambium forms secondary vascular tissues.
iv) Medullary parenchyma is present on the sides of vascular bundles in a dicot stem.