Question

As compared to a dicot root, a monocot root has
A. Many xylem bundles.
B. Inconspicuous annual rings.
C. Relatively thicker periderm.
D. More abundant secondary xylem.

Answer 1

Hint: Angiosperms are flowering plants that are mainly divided into two forms based on the number of cotyledons in the seed of the plants. Plants with a single cotyledon is called a monocot (monocotyledonous plant) and with two cotyledons is called a dicot or a dicotyledonous plant. Each of them shares other common features such as parallel venation in monocots and reticulate venation in dicots.

Complete answer:
Let us see the difference in root anatomy of both dicots and monocots. First let us see the dicots.
Dicot plants have taproots. The furthest or the outermost layer is known as the epidermis. The epidermal cells at times venture out which show up as the root hairs. The epidermis is trailed by the multi-layered cortex, approximately made of the parenchyma cells with intercellular spaces. The internal layer of the cortex is called endodermis, which is firmly stuffed by the barrel shaped cells. Endodermis is trailed by pericycle, which are a couple of layers of thick-walled parenchyma cells. In dicots, the pith in the centre is not distinct. There are two to four xylem and phloem. Pericycle, vascular packages and the central pith join to form steles in dicotyledons.
Next is monocots. Monocotyledons have a fibrous root system. Similar to the dicot root they have outer epidermis, followed by the cortex, pericycle, endodermis, xylem, phloem and a prominent pith. The vascular bundles are randomly scattered in the roots of monocotyledons. Conjunctive tissue is not involved in the formation of vascular cambium. The number of xylem bundles is much more in monocots than in dicots.

Hence, the right answer is option A.

Note:
In monocots, the vascular bundles are arranged in a ring-like form whereas in dicots it is arranged in the centre. In dicot plants, the xylem and phloem tissues are separated by a layer of cells known as conjunctive tissue that are parenchymatous. During the secondary development, the cambium isolates the xylem and phloem.