Mechanical fabric. Biology lesson "mechanical and conductive plant tissues" Mechanical and conductive plant tissues presentation

« Fabrics ».

Compiled by: Shubina S.G.

Biology teacher

MBOU "Secondary School No. 2"

G. Tarko-Sale

What is fabric

• Tissue is a collection of cells and intercellular substance that have a common origin, structure and perform certain functions.

Covering tissue

Covering tissues have a protective function. They are formed by living or dead cells with tightly closed, thickened membranes. These tissues are found on the surface of roots, stems and leaves.

Covering tissue

The integumentary tissue, which consists of living cells, is called the skin. Over time, a cork forms on some plant organs instead of the skin. The cork cells are dead, hollow, have thickened membranes

Mechanical fabric

Mechanical fabric gives strength to plants. They are formed by groups of cells with thickened membranes. In some cells, the membranes are lignified. The cells of mechanical tissue are often elongated and have the appearance of fibers.

Conductive fabrics

Conductive tissue is formed by living or dead cells that look like tubes. The nutrients dissolved in water move along them.

Conductive fabrics

* Vessels are dead hollow cells connected in series, the transverse partitions between which disappear.

* Sieve tubes are elongated non-nuclear living cells connected in series with each other. There are rather large holes in their transverse walls.

Basic fabrics

They occupy the space between integumentary, mechanical and conductive tissues. They are made up of living cells. Their main function is the synthesis and storage of various substances.

Educational fabrics

They are small, thin shell and relatively large core. They divide to form new cells from which other tissues are formed.

Homework:

§ 10 answer the questions.

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Slide captions:

Plant tissues of the Pokshengskaya Basic School No. 21 MOU Bogdanova LV 2010

Tissue is a group of cells that are similar in structure, function and have a common origin.

Intercellular spaces are spaces between cells in tissue. Heavyweight fabric Loose fabric

Plant tissue educational mechanical integumentary conductive basic

Educational tissue Young cells, capable of dividing, adhere tightly to each other

Educational tissue Provides plant growth

Main tissue The cells are old and have large vacuoles. Often the cells are loosely arranged, i.e. between the cells there are large intercellular spaces filled with air.

Main tissue Cells of photosynthetic tissue contain chloroplasts Function: Creation and accumulation of substances

Integumentary tissue The cells adhere tightly to each other. Often the cell membranes are impregnated with a cork substance.

Cover tissue Skin Cork Protects against adverse environmental conditions

Conductive tissues Wood (vessels) The cells are dead, the transverse membranes between them are destroyed. The entire vessel is impregnated with a cork substance Conducts water with dissolved minerals from the root to other organs (ascending current)

Conductive tissues Bast (sieve tubes) Cells are alive, old, membranes are pierced with holes, there are channels in the cytoplasm Conducts water with dissolved organic substances from the leaf to other organs (descending current)

Mechanical tissue Dead, narrow, long cells (fibers), membranes impregnated with a cork substance Stony cells Fibers

Mechanical tissue Gives strength and elasticity to organs (plant frame)

lower skin (integumentary tissue) upper skin (integumentary tissue) main tissue (with chloroplasts) mechanical tissue (fibers) conductive tissues (bast and wood) Leaf cross section

On the subject: methodological developments, presentations and notes

Plant transshipment and transplantation concept. The value and methods of handling a houseplant. Selection of flower pots for transshipped plants.

The teacher introduces children to the method of plant transplanting, called transshipment. With this method of transplantation, the root structure of the transplanted plant is not disturbed and the earthen lump is not damaged ...

Slide 1

Mechanical fabric Plan Mechanical fabric. Definition, function. Collenchyme. Cytological characteristics. Types. Sclerenchyme. Distinctive features. Primary and secondary sclerenchyma. Sclereids, structure, types. Distribution of mechanical tissues in a plant.

Slide 2

Turgor pressure of cells, a set of cell membranes, powerful integumentary tissue of perennial plants take part in ensuring the strength of the plant. However, the main component is mechanical tissues with cells with thickened membranes, which, after the death of the living cell contents, continue to perform a supporting function. Mechanical tissues can be either primary, derivatives of the main meristem or pericycle, or secondary - derivatives of cambium, phellogen, or the result of dedifferentiation of parenchymal cells. There are two main types of mechanical tissues: collenchyma and sclerenchyma.

Slide 3

Kollenchyma (Greek kolla - glue) is a mechanical tissue, the cells of which are unevenly thickened with cellulose and pectin substances. This is the primary tissue characteristic of dicotyledonous plants and is very close to the parenchyma; it contains protoplasts with all organelles. In shape, cells are often prosenchymal, less often parenchymal. Collenchyma is located in the shoot along the periphery, directly under the epidermis, or at a distance of one or more layers from it. More often forms a continuous annular layer, sometimes strands of cells in the ribs of herbaceous stems. Collenchyma appears in the early stages of shoot development. Its membranes are plastic and capable of stretching, which does not prevent the elongation of the organ, and contributes to the active growth of the plant. Found in young stems and roots, leaf stalks and veins. One of the features of collenchyma is that it fulfills its purpose only in a state of turgor. If the shoots lose water, they wither.

Slide 4

Corner - thickened walls in the corners of polyhedral cells (stalks of sorrel, pumpkin, buckwheat, beet); lamellar - thickened shells are located in parallel layers (stems of sunflower, young woody plants); loose - the walls of the cells bordering on the intercellular spaces are thickened (coltsfoot). Collenchyma is a living tissue consisting of elongated cells with unevenly thickened walls, capable of stretching and performing its functions only in a state of cell turgor. Sclerenchyma is the most common type of mechanical tissue among terrestrial higher plants.

Slide 5

Slide 6

Sclerenchyma (from the Greek scleros - hard) is the main mechanical tissue, consisting of tightly closed cells with uniformly thickened membranes. The cells are dead, their cavities are filled with air; cell walls are lignified. Sclerenchymal fibers are dead prosenchymal cells, polyhedral or rounded in cross-section with pointed ends, tightly adjacent to each other. The membranes are thickened, lignified, the pores are few, slit-like, the cell cavity is in the form of a narrow channel. Cellulose fibrils pass helically in the shells, and the direction of the turns in the layers alternates. Primary fibers are located in the leaves, stems and roots of plants, where they surround the primary vascular bundles. Secondary sclerenchyma is located in bark and wood. Recycled fibers include wood and bast fibers. Wood fibers or libriform have thickened and lignified shells. Bast fibers are called technical fibers - they have longer cells, but not always lignified, often retaining cellulose membranes. Bast fibers of some plants are widely used in industry. The most famous fibrous plants and products made from them are: hemp (Cannabis sativa) - ropes and ropes; jute (Corchorus capsularis) - ropes, cords and rough fabrics; kenaf (Hibiscus cannabinus) - rough tissue; flax (Linum usitatissimum) - weaving; ramie (Bochmeria nivea) - fabrics. For example, in flax the cell length reaches 60 mm, the longer ramie fibers are 350 mm, while the libriform fibers do not exceed 2 mm.

Slide 7

Sclereids are not fiber-shaped and vary greatly in shape. Sclereids are dead, more often parenchymal cells with very thick multilayered membranes, crossed by branching pores. Sclereids are found in all organs in the form of individual cells or clusters. Along with mechanical, it performs a protective function. By the shape of the cells, the sclereids are classified into: - brachyclereids or stony cells - isodiametric cells, the most common. Found in the shell of hazel, acorn; in the seeds of plum fruits, walnuts; in the pulp of pear, quince; in the peel of cedar pine seeds. - astrosclereids - branched, form outgrowths (prominences), which grow into the intercellular spaces by intrusive growth, are found in leaves of a leathery consistency (egg capsules, water lilies); - osteosclereids - resemble the shape of the tibia (bean peel); - macrosclereids - rod-shaped (beans); Sclereids can form continuous groups, tissue mass, like in a fruit shell. They can also be found singly, in the form of idioblasts, as, for example, in leaves. The set of thick-walled lignified plant cells, regardless of their origin, is called a stereome.

Slide 8

Slide 9

Distribution of mechanical tissues in a plant Bionics is a science that studies the architectonics of living organisms, i.e. construction and mechanical principles. V.F. Razdorsky divided the loads experienced by the plant into static - constant, caused by the force of gravity of the crown and dynamic - rapidly changing loads exerted by the wind, blows of rain. Two tendencies appear in the arrangement of mechanical tissue: centripetal and centrifugal. The basic principle is to achieve strength at an economical cost of material. Regularities of the location of mechanical tissue: Engineering "requirements" of plants change during ontogenesis. In the stems of young plants, a peripheral (centrifugal) tendency of the arrangement of mechanical tissues is manifested. Mechanical tissue is located on the periphery in the form of a hollow rigid tube. In the trunks and perennial branches, the center is strengthened to a greater extent, the mechanical tissue makes up the entire inner part (centripetal tendency). In the stems of monocotyledonous plants, resistance to stress is achieved by the fragmentation of the stereome, the mechanical tissue is located in the form of separate strands. A root surrounded by soil is not in danger of bending and breaking, its task is to resist tearing. Accordingly, mechanical tissues are placed in the center of the organ. In plant leaves, mechanical tissues resemble I-beams in arrangement, mechanical tissues are superficially bilateral.

"Life forms of plants" - Protants. Systematics according to the ecological (biogeocenotic) character. Caudex is developed in elecampane-tall (Elena), wormwood. The appearance of a plant, formed as a result of adaptation to environmental conditions. The most widespread classification of the Danish scientist K. Raunkier. 1905. Retractable roots - contractile roots. (Tulip, dandelion, etc.) Accumulation of substances in the root - kaudex.

"Modification of leaves" - Thorns. c) Insectivorous leaves. For what purpose are the organs being modified? Mamillaria. Leaf modifications: Peas. Remember: Round-leaved sundew. b) Antennae. Cereus. Mouse peas. The Venus flytrap is an insectivorous plant. Venus flytrap. Trichocerus. Leaf modifications. ? What are the functions of the sheet? ?

"Composition of plants" - Organism - organ -? ... Substances for the plant? Q-in from leaves to roots (rapid growth of roots) ... How to detect fats (oils)? Chemical substances (compounds) ... Metabolism is an important indicator of life. Higher: there are organs: stem, leaf ... Flower Fruit with seeds. -Chemical substances. Composition: consist of compounds, chem.

"Organs of a flowering plant" - III. The flower is a shortened, modified shoot that develops from a bud. The shoot is a part of the stem with leaves and buds located on it. Answer the questions: What plants are called flowering plants? Organs of flowering plants. Reproductive organ of flowering plants. Shoot Stem Leaves Shoot axis of the plant.

"Plant tissue" - Excretory (secretory) tissues. In higher seminal antheridia, they are reduced, and archegonia are present only in gymnosperms. Sieve tubes. Secondary meristems. Distinguish between: bast fibers (in the phloem); wood fibers (in xylem). Areas of intensively dividing cells, usually located above the nodes of the shoots.

"Fruit" - Tvarina-mi. Plan. With water. Juice fruit. For the nature of fertilization. 1. Growth of fruits. 2. Expanded fruit. 3. Value. Yabluko Orange. Kistianka Garbuzina. People. Odnonasіnnі Bagatonasіnnі. Fruit. Presentation Topic. Berry. Dry Juices Rozkrivnі Nerozkrivnі 2. For a few days. Bib Zernivka.

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