Question

Conjoint, closed type of vascular bundles are characteristic of

• A. Monocot stem
• B. Dicot stem
• C. Monocot root
• D. Dicot root

Answer 1

Answer: (A)

Monocot stem

Vascular bundles in monocots are generally scattered. Each vascular bundle has a covering called bundle sheath formed by a single layer of sclerenchyma cells. The vascular bundle encloses both xylem and phloem. Xylem is found towards the inner surface and phloem towards the outer surface. Cambium is absent. Hence, the vascular bundles are described as conjoint, collateral and closed.

Dicot stems vascular bundles are eight in number, arranged in form of a broken ring. The vascular bundles are conjoint, collateral and open. Xylem is on the inner surface and phloem on the outer surface. Xylem is described as endarch.

Vascular bundles of monocot root are radial in the arrangement. There are eight bundles each of xylem and phloem. Hence, the condition is described as polyarch. Xylem is described as exarch.

Dicot root vascular bundles are described as radial and tetrarch.

Therefore, the correct answer is option A.