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Mechanical plant tissues presentation. Mechanical and conductive fabrics. The outer skin is the covering tissue

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Classification of tissues by cell shape: Parenchyma - composed of isodiametric cells: meristems, integumentary cells Prosenchymal - composed of elongated cells (the length exceeds the width by 5-6 times or more): conductive, bast and wood fibers Classification by cellular composition: Simple - composed of one type of cell: collenchyma Complex - composed of morphologically different cytological elements: xylem, periderm Classification of tissues according to the state of cells: Living - consisting only of living cells: meristems Dead - consisting only of dead cells: sclerenchyma

VIII. Excretory tissues: External: - Glandular hairs (trichomes) and outgrowths (emergents); - Nectaries; - Hydathodes; Internal: - Excretory cells; - Multicellular receptacles for secretions; - Resin channels (resin channels); - Milkies (segmented and non-segmented)

2. Educational tissues Meristems, or educational tissues, are complex, living, parenchymal tissues with the ability to actively divide and form new cells Functions: formation of permanent tissues and ensuring unlimited plant growth Cytological composition: Initials - delayed at the embryonic stage of development, divide unlimitedly number of times with the formation of derivative meristem cells Derivative cells divide a limited number of times with subsequent differentiation into cells of permanent tissues

2. Secondary Lateral, or lateral, located parallel to the lateral surfaces of the axial organs, ensure their growth in thickness: - Cambium (gives rise to secondary conducting tissues) - Phellogen (gives rise to the periderm) Wound meristems are formed in places of damage to tissues and organs and give rise to callus – parenchymal tissue covering the wound site

Cytological characteristics: Cell shape: isodiametric, multifaceted Intercellular spaces are absent CS thin, with low cellulose content The nucleus is relatively large, occupies a central position Vacuoles are small, numerous Ergastic substances are absent Plastids - proplastids, small, few in number Mitochondria - small, few in number

Epidermis with stomata: 1 – initial letter, 2 – watermelon, 3 – corn, 4 – iris Covering trichomes: 1-3 – simple unicellular, 4 – simple multicellular, 5 – branched multicellular, 6 – simple bicornuate, 7,8 – star-shaped (in plan and in cross-section of the leaf)

Diagram of the structure of stomata: A – top view of the epidermis; B – cross-section of the stomatal apparatus: 1 – guard cells, 2 – stomatal fissure, 3 – secondary cells, 4 – substomatal cavity, 5 – epidermal cells, 6 – cuticle, 7 – spongy chlorenchyma cells

Epiblema (rhizoderm) is the primary single-layer tissue in the root absorption zone. Arises from the primary apical meristem of the root. Functions: Absorption of soil solution Protective Cytological characteristics: Cells are isodiametric, thin-walled without intercellular spaces, cuticles and stomata Rich in mitochondria Capable of forming root hairs (trichoblasts)

Secondary integumentary tissues Periderm - complex, parenchymal, multilayered secondary integumentary tissue of the stems and roots of perennial plants Formation: On shoots - from phellogen formed from the cells of the main parenchyma lying under the epidermis On roots - from the pericycle Functions: Protective Gas and water exchange

Types of periderm formation: 1 – in the subepidermal layer of elderberry, 2 – in the epidermis of willow, 3 – in the inner layer of the bark of fragrant raspberry; B – fibers, K – bark, Coll – collenchyma, P – periderm, F – phellem (cork), Fg – phellogen (cork cambium), Fd – phelloderm (cork parenchyma), E – epidermis

The crust (rhytidom) is a complex, parenchymal tertiary integumentary tissue. Formed as a result of repeated formation of new layers of periderm in the deep tissues of the bark Function: protective Oak bark: B - fibers, VK - secondary bark, D - calcium oxalate drusen, P - periderm, PC - remains of the primary bark

Xylem Xylem (wood) is a conductive tissue that provides an upward flow of water, inorganic and organic substances synthesized in root cells, to the terrestrial organs of the plant. By origin, they distinguish between primary (formed from procambium) and secondary (from cambium) Functions: Conductive Storage Supporting

The water-conducting elements of xylem are tracheids and vessels (tracheas). Tracheids are dead prosenchymal cells, narrowed at the ends and devoid of protoplast, bearing bordered pores of the cell wall. Vessels are hollow tubes consisting of vertically located segments separated by perforations. Types of secondary thickening and holding the side walls of the tracheal elements: 1 - annular, 2-4 - spiral, 5 - reticular, 6 - scalene, 7 - opposite, 8 - alternate

Composition: sieve elements, companion cells, several types of parenchyma cells, bast fibers, idioblasts Scheme of formation of phloem conducting elements: 1 - initial cell with a vacuole and tonoplast, 2 - formation of a sieve tube segment and accompanying cell, 3 - disintegration of the nucleus, tonoplast, EPR, formation of sieve perforations, 4 – final formation of perforations, 5,6 – clogging of perforations; V - vacuole, Ka - callose, Pl - plastids, Pr - perforations, SC - companion cells, T - tonoplast, I - nucleus

5. Mechanical tissues Mechanical tissues are supporting tissues that give strength to plant organs. Location: in shoots - along the periphery in roots - in the central part in leaves - according to the principle of an I-beam. By origin, primary (collenchyma) and secondary (sclerenchyma, sclereids) mechanical tissues are distinguished

Collenchyma is a simple primary supporting tissue, consisting of living, stretchable prosenchymal cells with thickened, non-lignified primary CS. Depending on the type of thickening of the CS, they are distinguished: Angular Lamellar Loose Collenchyma: 1- three-dimensional image of angular collenchyma; 2 – transverse section through lamellar collenchyma; 3 – loose collenchyma with intercellular spaces

Sclerenchyma is a mechanical tissue consisting of prosenchymal cells with lignified, less often non-lignified and unevenly thickened CS. Sclerenchyma cells = fibers: bast or wood (libriform), depending on whether they are part of phloem or xylem. By origin they are distinguished: primary (arises from the cells of the main meristem, procambium or pericycle) secondary (formed from cambium cells) Wood fibers of meadow geranium: A, B - transverse sections, C - longitudinal section; 1 – cell wall, 2 – simple pores, 3 – cell cavity

Sclereids are mechanical tissue cells, usually arising from the cells of the main parenchyma as a result of thickening and lignification of their CS. Functions: - resist compression; - protection from being eaten by animals Origin – primary. Sclereids: A, B – brachysclereids from the pulp of the fruit of the common pear and the core of hoya fleshy; B – macrosclereids of the “palisade” epidermal layer (1) in a bean seed; D – individual macrosclereids in longitudinal (a) and transverse (b) sections; D – osteosclereids in the seed coat of peas; E, G, H – astrosclereids in leaf blades of trochodendron, water lily, camellia; I – thread-like sclereids of olive tree

6. Basic parenchymal tissues Basic tissues are slightly specialized tissues that make up most plant body. Present in all vegetative and reproductive organs. Consist of living parenchyma cells with a primary CS. Some cells retain weak meristematic activity. They are classified according to the main function performed: wood, bast, primary bark, stem, pith, ray, assimilation, storage, aquifer, aerial, transfer cells of the leaf.

Assimilation tissue Anatomical structure of the assimilation area of the leaf: 1 - upper epidermis, 2 - lower epidermis, 3 - columnar chlorenchyma, 4 - spongy chlorenchyma, 5 - stomata, 6 - cuticle, 7 - air-filled intercellular spaces Chlorophyll-bearing parenchyma, chlorenchyma - tissue consisting of cells containing chloroplasts, performing the function of photosynthesis. The main volume of assimilation tissue is located in the leaves, less in young green stems

Storage tissues In storage tissues, metabolic products that are excessive during a given period of development are deposited: proteins, carbohydrates, fats, etc. They are represented mainly by large thin-walled living parenchyma cells, less often with thick CS (additional supporting function) Localization: endosperm and perisperm of the seed, metamorphosed roots and shoots, core of stems, parenchyma of conducting tissues

7. Excretory tissues Excretory (secretory) tissues include structural formations that can actively secrete metabolic products (secrets) and droplet water from a plant or isolate in its tissues. Found in all plant organs. Cells are parenchymal, thin-walled, for a long time remain alive Classification: internal secretion external secretion

Functions Protection from being eaten by animals, damage by pests and pathogenic microorganisms Resins and gums “protect” places of injury Nectar attracts pollinators Can act as reserve substances Places for “burial” of toxic substances excluded from metabolism

External excretory tissues Glandular hairs and peltate glands are trichomes (derivatives of the epidermis) 1 - pelargonium hair with excrement secreted under the cuticle; 2 – rosemary hair; 3 – potato hair; 4 – vesicular quinoa hairs with water and salts in vacuoles; 5 – peltate gland of blackcurrant leaf

Nectaries secrete a sugary liquid and are most often found in flowers. Excretory cells have dense cytoplasm and high activity metabolism. A vascular bundle may approach the nectary. Nectary in a marigold flower: GV – glandular hairs; N – nectary tissue; PP – vascular bundle Floral nectaries: A – narcissus in the form of a depression in the ovary; B – external at the base of tea stamens; B – coccolobs in the form of rings under the stamens; G – euphorbias in the form of disks under the ovary; D – euonymus in the form of discs between the ovary and stamens; E – umbrella-shaped in the form of disks in the upper part of the lower ovary; F – jute in the form of cushion-shaped collections of hairs; H – plum lining the inside of the hypanthium; I – cinnamon in the form of staminodes; K – flax in the form of glands at the base of the stamens (1 – nectrons; 2 – staminodes)

Hydathodes release droplet-liquid water and salts dissolved in it. Guttation is the phenomenon of squeezing out drops of water through hydathodes when there is an excess supply of water to the plant and weakened transpiration. Digestive glands of insectivorous plants. The secretion contains enzymes and acids. Hydathode in a leaf of Crassula purslanaceae: 1 – view from the surface; 2 – cross section; VU – water stomata; G – hypodermis; About – lining; PP – conductive bundle; E – epidermis; Ep - epithema

The receptacles of secretions are varied in shape, size and origin: Schizogenous EVs arise from intercellular spaces filled with secreted substances and surrounded by living epithelial cells (resin pods of pine, araliaceae, umbellaceae, asteraceae) Lysigenous EVs are formed in place of groups of cells that disintegrate after the accumulation of secretions (citrus fruits) Development scheme schizogenic resin canal: 1-3 – on transverse sections; 4 – in a longitudinal section; P – channel cavity; E - epithelium

Laticifers - living cells containing milky sap in vacuoles. Latex - milky sap containing resins, rubber, essential oils, protein compounds, alkaloids (Hevea brasiliensis, kok-sagyz, tau-sagyz, euonymus) Types of laticifers: Segmented are formed from many lactiferous cells, in places of contact with dissolved membranes, merging into a single branched system of protoplasts and vacuoles (poppy, bellflower, aster ) Non-segmented - one giant cell, which, having arisen in the embryo, no longer divides, grows and branches (euphorbia, mulberry) Miltifers: 1 - articulated lacticifer; 2 – unsegmented laticifer

Slide 1

Mechanical fabric Plan Mechanical fabric. Definition, functions. Collenchyma. Cytological characteristics. Types. Sclerenchyma. Distinctive features. Primary and secondary sclerenchyma. Sclereids, structure, types. Distribution of mechanical tissues in the plant.

Slide 2

The following factors take part in ensuring the strength of the plant: turgor pressure of cells, the totality of cell membranes, and powerful integumentary tissue of perennial plants. However, the main component is mechanical tissues with cells with thickened membranes, which, after the living contents of the cell die off, 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 parenchyma cells. There are two main types of mechanical tissues: collenchyma and sclerenchyma.

Slide 3

Collenchyma (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 very close to parenchyma, containing protoplasts with all organelles. The shape of the cells is 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 several layers from it. More often it 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 shells are plastic and capable of stretching, which does not interfere with the elongation of the organ and promotes the active growth of the plant. Found in young stems and roots, petioles and leaf 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 - the walls in the corners of multifaceted cells are thickened (sorrel, pumpkin, buckwheat, beet stems); lamellar - thickened shells are arranged in parallel layers (sunflower stems, young woody plants); loose - the walls of the cells bordering the intercellular spaces are thickened (coltsfoot). Collenchyma is 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 higher terrestrial plants.

Slide 5

Slide 6

Sclerenchyma (from the Greek scleros - hard) is the main mechanical tissue, consisting of tightly closed cells with evenly thickened membranes. The cells are dead, their cavities are filled with air; cell walls become lignified. Sclerenchyma fibers are dead prosenchymal cells, multifaceted or round 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 through the shells in a helical manner, 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 the bark and wood. Secondary fibers include wood and bast fibers. Wood fibers or libriform have shells that are highly thickened and lignified. Bast fibers are called technical fibers - they have longer cells, but not always lignified, often retaining cellulose shells. Bast fibers from some plants are widely used in industry. The most famous fibrous plants and products made from them are: hemp (Cannabis sativa) - ropes and cords; jute (Corchorus capsularis) – ropes, ropes and coarse fabrics; kenaf (Hibiscus cannabinus) – coarse fabrics; 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 do not have the form of fibers and vary greatly in shape. Sclereids are dead, mostly parenchyma cells with very thick multilayer membranes crossed by branching pores. Sclereids are found in all organs in the form of individual cells or clusters. Performs a protective function along with a mechanical one. According to the shape of the cells, sclereids are classified into: - brachysclereids or stony cells - isodiametric cells, the most common. Found in the shells of hazel and acorn fruits; in the pits of plum fruits, walnut; in the pulp of pear and quince fruits; in the seed coat cedar pine. - astrosclereids - branched, form outgrowths (protuberances), which grow into intercellular spaces by intrusive growth, found in leaves of a leathery consistency (pods, water lilies); - osteosclereids - resemble the shape of the tibia (bean skin); - macrosclereids – rod-shaped (beans); Sclereids can form continuous groups, a tissue mass, as in the shell of a fruit. They can also occur singly, in the form of idioblasts, as, for example, in leaves. A collection 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, exerted by the force of gravity of the crown and dynamic - rapidly changing loads, exerted by wind and rain blows. There are two tendencies in the arrangement of mechanical tissue: centripetal and centrifugal. The main principle is to achieve strength with economical use of material. Patterns of arrangement of mechanical tissue: Engineering “requirements” of plants change during ontogenesis. In the stems of young plants, a peripheral (centrifugal) tendency for the arrangement of mechanical tissues is manifested. The mechanical tissue is located along the periphery in the form of a hollow rigid tube. In 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 monocots, resistance to stress is achieved by fragmentation of the stereom; the mechanical tissue is located in the form of separate strands. A root surrounded by soil is not in danger of bending or breaking; its task is to resist rupture. In accordance with this, mechanical tissues are placed in the center of the organ. In plant leaves, the mechanical tissues in arrangement resemble I-beams; the mechanical tissues are located superficially on both sides.

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Slide captions:

Plant tissues MOU "Pokshengskaya basic school No. 21" Bogdanova L.V. 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. Thick 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

Ground tissue The cells are old and have large vacuoles. Often the cells are arranged loosely, that is, between the cells there are large intercellular spaces filled with air.

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

Integumentary tissue Cells adhere tightly to each other. Cell membranes are often impregnated with a cork substance

Cover tissue Peel Cork Protects from adverse environmental conditions

Conducting tissues Wood (vessels) 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 (upward current)

Conducting tissues Lube (sieve tubes) The cells are living, old, the membranes are permeated with holes, there are channels in the cytoplasm Conducts water with dissolved organic substances from the leaf to other organs (downward current)

Mechanical tissue Cells are dead, narrow, long (fibers), membranes are impregnated with cork substance Stony cells Fibers

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

lower skin (integumentary tissue) upper skin (integumentary tissue) ground tissue (with chloroplasts) mechanical tissue (fibers) conductive tissues (bast and wood) Cross section of a leaf

On the topic: methodological developments, presentations and notes

The concept of transshipment and replanting of plants. The meaning and techniques of transshipment of a houseplant. Selection of flower pots for transshipment plants.

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

Mechanical and conductive tissues emerged
in the process of evolution due to the transition
to life on dry land.
In algae and mosses these tissues are poorly developed.

TYPES OF PLANT TISSUE:
1. Educational tissues (meristems):
2. Integumentary: primary (epidermis, epiblema);
secondary (periderm, crust);
3. Mechanical (support):
collenchyma
sclerenchyma (fibers, sclereids).
4. Conductive:
xylem (wood);
phloem (bast).
5. Excretory:
external (glandular hairs, nectaries, hydathodes);
internal (receptacles for secretions, lacticifers, tubules, etc.).
6. Parenchyma (aerenchyma, chlorenchyma, storage).

All tissues originate from meristems.

There is a whole system in the plant body
mechanical fabrics,
which give
strength and hardness
throughout the plant body,
protect organs
from rupture, stretching,
damage.
Mechanical tissue cells
mostly dead
with thickened shells
(leaked lignin)

There are 2 main types
mechanical (support) fabrics:
1) collenchyma
2) sclerenchyma (fibers, sclereids)

Collenchyma is a living mechanical tissue
with unevenly thickened cell membranes
(some areas of the shell remain thin,
while others are greatly thickened.
Collenchyma is a tissue of primary origin,
its cells are elongated, somewhat slanted
ends, often contain chloroplasts.
In shells along with cellulose
contains a lot of pectins and hemicellulose.
In the body of the plant, collenchyma is located immediately
under the integumentary tissue of the stem,
in petioles and veins of leaves, pedicels.

There are 3 types
collenchyma:
corner,
lamellar
loose.

2) Sclerenchyma – dead
mechanical fabric with
evenly thickened
cell membranes. shells of her
cells leaked with lignin
(lignified), which increases
their strength. There are 2
main types of sclerenchyma:
a) Sclerenchyma fibers
consist of prosenchymal
the shape of cells, highly elongated in
long and pointed at the ends.
They usually have thick
walls and a very narrow cavity
inside. They are in the body of the plant
usually arranged in groups.

b) Sclereids - mechanical tissue with cells
parenchymal shape - stellate, rod-shaped,
thread-like, branched. Their shell is very thick,
lignified (leaked with lignin), there is a lot of
simple or branched pores. Sclereids may be
located in different parts plants: stems (birch),
seed peel, fruits (walnut, cherry, pear).

Sclereids
in medicinal
raw material - oak bark

Conductive
fabrics
provide
movement of substances in
body of the plant. There are 2
types:
1) xylem
2) phloem.
Along the xylem in the direction from below
up, from roots to leaves,
moves
water
With
dissolved
V
her
mineral
substances
(rising current). By phloem in
direction from top to bottom, from
leaves
To
roots,
move around
organic
substances,
educated
V
leaves
V
process
photosynthesis.

XYLEM is a complex tissue.
Its composition includes:
conducting tissues (vessels and tracheids) are its main
elements
mechanical (sclerenchyma wood fibers);
the main woody parenchyma where products accumulate
stock.

Vessels are dead elongated tubes,
which are made up of many cells
called vascular segments.
They are formed from vertically
located cambium cells.
At the junction of the segments
their transverse shells
dissolve (disappear) or in them
through holes appear.
Tracheids are dead, elongated
cell length with pointed ends,
xylem of gymnosperms.
Thanks to the thickening of the shell
they also perform mechanical functions.

PHLOEM is also
complex (complex)
cloth. Its composition
includes:
conductive fabric –
sieve tubes and
companion cells;
mechanical fabric
(sclerenchyma bast
fiber);
basic bast
parenchyma (with reserve
nutrients and
also crystals
calcium oxalate).

In plant organs, xylem and phloem are usually located
nearby, forming conducting bundles

Depending on the relative position xylem and phloem
conducting bundles are divided into 4 main types:
- Collateral (closed and open);
- Bicollateral;
- Concentric;
- Radial.

TYPES OF PRODUCING BUNCHES

A – collateral
closed
B – collateral
open
B – bicollateral
open
G – radial
D – concentric
centrifloem
E – concentric
centroxylem:
1 – phloem;
2 – xylem;
3 – cambium.

« 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 specific functions.

Integumentary tissues

Integumentary tissues perform 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.

Integumentary tissues

The covering tissue consisting of living cells is called the skin. Over time, a plug forms on some plant organs instead of a skin. Cork cells are dead, hollow, have thickened membranes

Mechanical fabric

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

Conductive fabrics

Conducting tissues are formed by living or dead cells that look like tubes. Nutrients dissolved in water move along them.

Conductive fabrics

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

* Sieve tubes are elongated, nuclear-free living cells connected in series to each other. There are quite large holes in their transverse walls.

Main fabrics

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