Question

A stele consisting of numerous closed vascular bundles is called as
A)Eustele
B)Dictyostele
C)Atactostele
D)Solenostele

Answer 1

Sclerenchymatous sheath-covered vascular bundles are constituted in the monocot stem and they are called fibro vascular bundles. It is existing in a shape of eustele, in which the vascular bundles in a ground tissue are dispensed or spirally arranged. In monocots, such as maize and rye, fibro vascular bundles are known to occur.

Complete answer:
A vascular bundle is an important phase of the vascular plant transport system. Transportation itself occurs in vascular tissue, which has two forms: xylem and phloem. Both of these tissues are located in a vascular bundle that might also encompass helping and protecting tissues in addition. Vascular bundles in the monocotyledon leaf are protected by means of parenchymatous cells.

Now let us find solution from given options:
Eustele : The primary vascular tissue made up of vascular bundles, usually in one or two rings around the pith is termed as eustele.
Dictyostele : A stele in which the vascular cylinder is divided up into a longitudinal series or network of vascular strands around a central pith is termed as dictyostele.
Atactostele : Monocot stems, in which the stele consists of a complex arrangement of quite a few vascular bundles, are stated to have an atactostele. Atactostele is a stele with fibro vascular bundles allotted in arrangement. The outer vascular bundles of an atactostele are smaller than the internal vascular bundles.
Solenostele : Solenostele is a kind of siphonostele, in which the vascular tissue in the stem produces a central cylinder around a pith, with widely spaced leaf gaps.

Hence, the correct answer is option (C)

Note: In the monocot stem, vascular bundles are covered and enclosed by sclerenchymatous fibres. In the monocot root, there is absence of coating around the vascular bundles. In the dicot stem, there is absence of covering around the vascular bundles.