Question

Vascular bundles in dicot stems are:
(a)Open, collateral, endarch
(b)Closed, collateral, endarch
(c)Open, collateral, exarch
(d)Closed, collateral, exarch

Answer 1

Hint: Vascular bundles are a collection of tube-like tissues that flow through plants and are a part of the transport system, transporting critical substances to various parts of the plant. The vascular bundle consists of two forms: xylem and phloem.

Complete step-by-step answer:
Xylem transports water and nutrients and phloem transports organic molecules, these, in addition, will include supporting and protective tissues, phloem on the outer surface, and xylem on the inside. Because of the presence of cambium the vascular bundles of dicot stem are open. In the dicot stem, vascular bundles are arranged in a ring around the pith and the pith is concentrated at the core of the stem.

Xylem is described as an endarch and is used when there is more than one strand of primary xylem in a stem or root. The xylem develops from the inside towards the periphery, i.e., centrifugally. The protoxylem is closest to the center of the stem or root and the metaxylem closest to the periphery of the stem. The stems of dicot plants typically have endarch development and the roots are normally considered to have exarch development. Closed vascular bundles are present in monocots as they lack cambium. Vascular bundles in monocot stems are closed, collateral, and endarch.

So, the correct answer is ‘open, collateral, endarch’.

Note: The stems of dicot plants have a well-defined epidermis with a cuticle, a layer of dermis along with multicellular stem hair. Examples are sunflower and Cucurbita. Cambium separates xylem and phloem, and all the tissue from the cambium layer outward is considered bark, while all the tissue inside the cambium layer to the center of the tree is wood.