Explain about Plant tissues
9th Class AP SCERT
points ➡ 50
Answers
Types of plant tissues system
Dermal Tissue
They are the tissues, which covers the external part of the herbaceous plants.
They are composed of epidermal cells, which secrete the waxy cuticle.Waxy cuticles are responsible for protecting plants against water loss.Dermal tissue consists of Epidermis and periderm. Epidermis
They are the outermost layer of the primary plant body, which covers roots, stems, leaves, floral parts, fruits and seeds.
They are one layer thick with cuticle.
They are composed mostly of unspecialized cells- parenchyma and sclerenchyma.
They include trichomes, stomata, buIIiform ceIIs, etc.
Periderm
They are the outermost layer of stems and roots of woody plants such as trees. They are also called as barks.
They replace epidermis in plants that undergo secondary growth.They are multilayered structures.They include cork cells, which are nonliving cells that cover the outside of stems and roots. The periderm protects the plant from injuries, pathogens and also from excessive water loss.
Ground Tissue
Sclerenchyma
They are rigid, non-living cells.
They have thick, lignified secondary walls and lack protoplasts at maturity.
They provide strength
A sclerenchyma cell also provides a support to plants with the help of hardening agent present in their cells.Sclerenchyma cells are of two types:
Sclereids: They are short, irregular in shape and have thick, lignified secondary walls
Fibers: They are long, slender and are arranged in threads.
Vascular Tissues
They are specialized cells with transport of water, hormone and minerals throughout the plant.
They contain transfer cells, fibers in addition to xylem, phloem, parenchyma, cambium and other conducting cells.
They are located in the veins of the Leaves.
Xylem
They are dead with hollow cells, which consist of only cell wall.
They play a vital role in transporting water and dissolved nutrients from the roots to all parts of a plant.
They transport the nutrients in the upward direction .i.e. from the root to the stem, leaves and flower.
Xylem is also called as water-conducting cells.
Phloem
They are live cells, which lack nucleus and other organelles.
They transports dissolved organic food materials (sugars) from the leaves to all parts of a plant.
They transport the nutrients in the downward direction .i.e. from the leaves to the different parts of the plant.
Phloem is also called as sugar-conducting cells.
Types of plant tissue
Meristematic Tissues
Meristematic tissues are group of cells, which have the ability to divide. This tissue consists of small, cubodial densely packed cells, which keeps on dividing to form new cells. These tissues are capable of stretching, enlarging and differentiate into other types of tissues as they mature. Meristematic tissues give rise to permanent tissues.
General characteristics of Meristematic tissues
They have very small cells with thin cell walls.
Their cells have large nuclei.
Their cells have very small vacuoles and they lack intercellular spaces.
They remain young forever and divide actively throughout the life of the plant.
Permanent Tissues
The tissues, which are derived from the Meristematic tissues, are called as permanent tissues. They are the tissues, which have lost their ability to divide as they have attained their mature form.
Kinds of Permanent Tissues
Simple permanent tissue: They are the tissues, which are similar in function and are called as simple because they are composed of similar types of cells, which have common origin and function. Complex permanent tissue: They are the tissues, which are composed of two or more types of cells but contribute to a common function are called complex tissues.
Plant Tissue Functions
Different types of plant tissue have their own respective functions.
The plant tissue helps in providing mechanical strength to both the internal and external organs.They also help in rendering the elasticity and flexibility to the organs. The tissue also helps in easy bending in various parts of a plant like- leaf, stem and branches without causing any damages to main plant.The tissue also helps transportation of materials thorough out the plants and prevents water loss.They divide to produce new growth and build the mass of the plants.They are involved in various cellular metabolisms like photosynthesis, regeneration, respiration, etc.
Answer:
Explanation:
Plant tissue is a collection of similar cells performing an organized function for the plant. Each plant tissue is specialized for a unique purpose, and can be combined with other tissues to create organs such as leaves, flowers, stems and roots. The following is a brief outline of plant tissues, and their functions within the plant.
there are three types-
1)Meristematic Tissue
2)Simple Plant Tissue
3)Complex Plant Tissue
Meristematic Tissue
Meristematic plant tissue is different than all other plant tissue, in that it is the main growth tissue of the plant. All cells originate from one meristem or another. The apical meristem is the plant tissue which drives above ground growth, and decides the direction of the plant. Root meristems dig into the soil in search of water and nutrients. Subapical meristems divide the plant and carry leaves in different directions. Intercalary meristems provide growth from the middle of the plant, to extend the leaves upward into the sunlight.
Simple Plant Tissue
There are several basic forms of plant tissue, formed from mostly identical types of cells. The first is the epidermis. The epidermis in plants serves the same function as it does in animals. It is a plant tissue formed of thin and densely packed cells, meant to separate the inside of the organisms from the outside. The epidermis is often covered in a layer of waxy protection, to stop the plant from burning or drying out in the sun. The epidermis also contains guard cells, which operate small opening called stoma. These stoma control the passage of air and water through the leaves, allowing plants to move water and nutrients up from the soil.
Complex Plant Tissue
The complex tissues in a plant deal with moving nutrients and water to the leaves, while removing the products of photosynthesis from the leaves. Photosynthesis produces the sugar glucose. Modified and bound to other 6-carbon sugars, the substance becomes sucrose or a variety of other disaccharides. In this form it can be moved with small amounts of water and can be transported efficiently throughout the plant. The complex tissues of the plant aid in this overall effort to supply the roots with food as they supply the leaves with water and nutrients.