Anatomy of Flowering Plants

$\bullet$ When the cells of medullary rays differentiated, they give rise to the new cambium called interfascicular cambium.

$\bullet$ Loose parenchyma cells rupturing the epidermis and forming a lens-shaped opening in bark are called complementary cells.

$\bullet$ Large colorless empty cells in the epidermis of grass leaves are called bulliform cells.

$\bullet$ In dicot leave, vascular bundles are surrounded by large thick walled cells called bundle sheath cells.

Correct statement: Sapwood is outermost secondary xylem.

Outer secondary xylem or sapwood serves in water conduction, while the inner part called heartwood is composed of dead but structurally strong primary xylem.

The roots that originate from the base of the stem are fibrous roots.

A fibrous root system is the opposite of a taproot system.

It is usually formed by thin, moderately branching roots growing from the stem.

A fibrous root system is universal in monocotyledonous plants and ferns.

The fibrous root systems look like a mat made out of roots when the tree has reached full maturity.

The monocot stem is characterised by conjoint, collateral, and closed vascular bundles, scattered in the ground tissue containing the parenchyma.

Each vascular bundle is surrounded by sclerenchymatous bundle-sheath cells.

Phloem parenchyma and medullary rays are absent in monocot stems.

Heartwood is inactive physiologically due to deposition of organic compounds and formation of tyloses so it will not conduct water and minerals.

In roots, the root hairs develops from zone of maturation. This zone is differentiated zone thus bearing root hairs.

Cells of vascular cambium divide periclinally both on the outer and inner sides to form secondary permanent tissues, i.e., secondary xylem and secondary phloem.

Cork cambium undergoes periclinal division and cuts off thick walled suberised dead cells towards outside i.e. phellem (cork) and it cuts off thin walled living cells i.e., phelloderm on inner side.

Tyloses are balloon-like extensions of parenchyma cells that protrudes into the lumen of a neighbouring xylem vessel or tracheid through a pit in the cell wall.

Tyloses form most commonly in older woody tissue, possibly in response to injury, they may eventually block the vessels and thus prevent the spread of fungi and other pathogens within the plant.

Tyloses may become filled with tannins, gums, pigments, etc., giving heartwood its dark colour, and their walls can remain thin or become lignified.

In botanical terms, the cortex of a plant is the region found between the epidermis and the stele.

Therefore, the correct answer is: Option C: Epidermis and stele.

To clarify: Epidermis: This is the outermost layer of cells in the plant stem and root.

It serves as a protective barrier against the external environment.

Stele: This is the central part of the root or stem, containing the vascular tissue (xylem and phloem), pith, and often a pericycle.

The stele is located inside the endodermis.

The cortex lies between these two layers, functioning mainly in storage and transport of nutrients and water.

It is composed primarily of parenchyma cells and is a significant part of the root and stem where it often stores starch.

The other options refer to different parts of the plant anatomy: Option A: Endodermis and pith - The pith is located in the center of the stem, surrounded by the vascular tissue, which is inside the endodermis.

The cortex is not between these two.

Option B: Endodermis and vascular bundle - The endodermis is a single layer of cells forming a boundary between the cortex and the stele; it doesn't define the boundaries of the cortex.

Option D: Pericycle and endodermis - The pericycle is a layer of cells found just inside the endodermis, and it is part of the stele.

This option does not correctly describe the position of the cortex.

Thus, Option C is the most accurate in describing the location of the cortex in a plant.