Question

Cortex is the region found between
(A) Endodermis and vascular bundles
(B) Epidermis and stele
(C) Pericycle and endodermis
(D) Endodermis and pith

Answer 1

Hint: Cortex is the region found between the outermost, protoderm-derived layer of cells covering the stem, and the central part of the root or stem containing the tissues derived from the procambium.

Complete answer:
Cortex is the region found between Epidermis and stele. A cortex in simple terms is defined as the outer layer of a stem or root in a plant, lying below the epidermis but outside the vascular bundles. it's also the surface layer or "skin" of the non fruiting part of the body of some lichens.

The cortex consists mostly of enormous thin- walled parenchyma cells of the ground tissue system and shows little to no structural differentiation.

Additional Information:
- Epidermis, related to plants, is defined as the outermost, protoderm- derived layer of cells which helps in covering the stem, root, leaf, flower, fruit, and seed parts of a plant. The epidermis along with its waxy cuticle acts as a protective barrier that protects from mechanical injury, water loss, and also in the case of infection. Various modification of epidermal cells helps to regulate transpiration, increase water absorption, and secrete substances.
- The stele is known to be the central part of the root or stem of the plant containing the tissues derived from the procambium. These mainly include vascular tissue, but in some cases, it also includes the ground tissue which is also known as pith, and a pericycle, which, if present, defines the outermost boundary of the stele. Outside the stele lies the endodermis, which is that the innermost cell layer of the cortex.
So, the correct answer is ‘(B) Epidermis and stele’.

Note: The stele is of two types i.e Eustele and Atactostele. The major difference between eustele and an actostele is only that the eustele contains vascular bundles in one or two rings. But, the atactostele contains many vascular bundles, which are scattered throughout the stem. Furthermore, eustele occurs in the stem of dicotyledons and the root of monocots, but atactostele occurs in the stem of monocots.