Question

Write any three functions of the epidermal tissue system?

Answer 1

Hint: The epidermis is a single layer of cells covering the leaves, flowers, roots, stems of plants, and forming a boundary between the plant and the external environment. The epidermis serves many functions: it protects against water loss, regulates gas exchange, secretes metabolic compounds, and absorbs water and mineral nutrients (especially in roots).

Complete answer:
The epidermis is the outermost cell layer of the primary plant body. In some older works the cells of the leaf epidermis have been considered as specialized parenchyma cells, but the conventional modern preference has long been to classify the epidermis as dermal tissue and parenchyma is classified as ground tissue. The epidermis is the major component of the dermal tissue system of leaves and also stems, roots, flowers, fruits, and seeds. It is usually transparent because epidermal cells have fewer chloroplasts or lack them completely, except for the guard cells.

The epidermis of most leaves shows dorsoventral anatomy: the upper (adaxial) and lower (abaxial) surfaces that show different construction and may serve different functions. Woody stems and some other stem structures such as potato tubers develop a secondary covering called the periderm that replaces the epidermis as the protective covering.

The functions of the epidermal tissue system are as follows.

-This tissue system in the shoot checks excessive loss of water due to the presence of cuticles.
- Epidermis conserves the transpiration and gaseous exchange.
- Stomata involved in transpiration and gaseous exchange.
- Trichomes are greatly helpful in the dispersal of seeds and fruits.
- Root hairs absorb water and mineral salts from the soil.

Note: The epidermal tissue includes many differentiated cell types: epidermal cells, guard cells, subsidiary cells, and epidermal hairs (trichomes). The epidermal cells are greatly numerous, largest, and least specialized. These are generally more elongated in the leaves of monocots than in those of dicots.