Plant organs. We form the basic biological concepts

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Floriculture, role and tasks.

List the main organs of plants, their functions and significance.

1. Floriculture as an integral part of green building is designed to play an important role in improving the landscapes of residential and industrial areas.

Floriculture as a branch of crop production is based on the principles of modern biology. The biological basis of floriculture is the knowledge of the characteristics of the growth and development of flower crops, their needs for environmental factors in order to develop the most rational methods of agricultural technology. The ultimate task is to study the patterns of formation of the maximum yield of flower products at high quality indicators and at the lowest cost. Modern floriculture is an industrial branch of crop production.

Floriculture is one of the most profitable branches of agriculture.

2. Root- the vegetative organ of a plant, which first appears during seed germination. The root grows, branches and forms a root system.

The root system is the totality of all the roots of a single plant. It comes in 3 types:

1) Rod;

2) Fibrous;

3) Mixed.

A plant with a rod system does not tolerate transplanting well. A plant grown by the seedling method always has a fibrous root system. The junction of the root with the stem root collar.

Root functions:

1) Holds the plant in the soil;

2) Absorbs water and nutrients dissolved in it;

3) May be a place of deposition of nutrients;

4) The root breathes, absorbs oxygen.

Root modifications:

Root crop- this is a modified root containing a supply of nutrients - in (carrots, beets)

Pip- it is an underground modified root (dahlia)

aerial roots, they absorb moisture from the air, serve as support and additional nutrition (monstera)

Nodules are formed in leguminous plants, they absorb free nitrogen from the air and turn it into complex compounds necessary for plant nutrition.

Stem- vegetative organ.

stem functions:

1) Connects the aboveground and underground parts of the plant

2) Is a conductor of nutrients - in

3) Distributive and educational function

4) Can be a reproductive organ

The structure of the stem is lignified, semi-lignified, green. According to the nature of growth, the stem is: erect, clinging, curly, creeping, climbing. The stem with leaves and buds is called escape.

Parts of the shoot: the junction of the leaf with the stem is called node, the distance between nodes is called internode, the angle between stem and leaf is called sinus sheet.

Bud- this is a strongly shortened shoot with rudiments of leaves or flowers.

Rhizome is an underground stem with modified leaves and buds.

Tuber- this is an underground stem containing a large supply of nutrients - c.

Corm is an underground stem with conspicuous round internodes.

thorn- a modified stem located in the axil of the leaf.

The stem can perform the function of a leaf, then the leaf is reduced to a scale, if the stem performs the function and looks like a leaf, such a modification is called phyllocladia.. If the stem performs a function and does not look like a leaf, then such a modification is called cladody.

Sheet- a vegetative organ, it consists of a leaf blade, petiole and stipules. Leaves are simple and complex. The petiole serves to attach the leaf to the stem. If the leaf does not have a petiole, it is called sessile. Leaf arrangement: next, when the leaves go one after another, opposite, when the leaves are located on top of each other, whorled, the leaves are arranged in a bunch.

Sheet functions:

Photosynthesis- the formation of organic things from inorganic.

Gas exchange, i.e., the leaf simultaneously absorbs and releases oxygen and carbon dioxide.

transpiration- this is evaporation that protects the plant from overheating.

Flower- this is a strongly shortened shoot with modified leaves adapted for sexual reproduction.

Main properties: decorative, seed and fruit formation.

The concept of plant organs

Definition 1

Organ A part of a plant organism adapted to perform one or more functions.

In plants, two groups of organs interconnected into an integral system are distinguished - vegetative and generative.

The vegetative ones include the root and shoot, consisting of a stem, leaves and buds, and the generative ones include a flower, fruit and seed (in spores it is sporangia, in gymnosperms it is a cone).

Vegetative organs of plants

Definition 2

Vegetative organs (from Latin vegetativas - plant) in plants are those that support the basic life processes, that is, perform the main functions of its nutrition and metabolism with the environment.

These organs were formed as a result of the dismemberment of a homogeneous body of lower plants (algae) - thalom. The reason for this was the transition from aquatic to terrestrial way of life.

One of the common features of vegetative organs is their polarity. Each organ has two poles: the upper, or apical, and the lower, or main. Vegetative organs are able to orient themselves in space in a certain way: the root always grows towards the center of the Earth (positive geotropism), the stem - from the center of the Earth (negative geotropism). The axial organs - the stem and root - are located vertically to the Earth's surface (orthotropic organs), and the leaves are at an angle (plagiotropic organs). This specialization is due to two areas of plant nutrition (soil and atmospheric), which means a two-way flow of water with dissolved mineral and organic substances.

The root has unlimited growth, has no leaves. Provides absorption and transportation of water and compounds dissolved in it, synthesis (and often storage) of substances, respiration.

Stem in typical cases - an axial polysymmetrical organ of unlimited growth. The stem provides a connection between the leaves and roots, promotes the formation of a strong assimilation surface of the leaves and their best placement relative to the light, and stores nutrients.

Sheet- a lateral organ of limited growth, grows by the base by intercalary growth (in monocots) or by the entire surface (in dicots). The leaf consists of a leaf blade and petiole, stipules; leaves without a petiole are called sessile (rye). In annual plants, the life span of a leaf is similar to the life span of a stem. Trees and bushes have a temporary organ. The main functions of the leaf: photosynthetic, gas exchange, transpiration, reproduction, protective (thorns), cleansing (leaf fall), nutritious (dew).

Remark 1

Vegetative organs do not take part in sexual reproduction, but still they can contribute to the so-called vegetative method of plant propagation (using rhizomes, tuber bulbs, mustaches, etc.). With this method of reproduction, a new organism grows from the multicellular part of the mother organism.

The division of the body of plants into organs and the formation of a large number of branches, leaves and roots made it possible to develop a huge photosynthetic surface and absorb a sufficient amount of water and mineral elements.

plant generative organs

Definition 3

Generative (reproductive) organs(from lat. genero - give birth) plants arose much later than vegetative ones. The flower, the seed and the fruit that are formed from it, are considered the highest achievement of the process of reproduction in the plant world. Thanks to the generative organs, the process of sexual reproduction is ensured.

The generative organs of flowering plants are flowers, due to which fruits with seeds are formed. The process of sexual reproduction of flowering plants occurs when the plant blooms (flowers open).

In shape, size, color and structural features, flowers are very diverse. However, the basic structure and processes of flower development are identical in all plants. The flower has stamens, pistils and perianth (petals and calyx). The main function of the stamens is the formation of pollen grains with male sex cells (sperms). In the pistils are the seed rudiments, and in them are the female sex cells (ova).

As a result of fertilization, a seed is formed from the seed germ, inside of which there is an embryo and endosperm under the skin. The seeds are surrounded by a pericarp, which was formed from the walls of the ovary. Together, the seeds and the pericarp form the fruit. After a dormant period, the seeds germinate under favorable conditions and a young plant develops from them.

Remark 2

The generative organs of spore plants - mosses, horsetails, ferns - have a different structure.

The body of most plants consists of tissues and organs. Each organ can consist of several types of tissues. Each tissue consists of a special kind of cells, that is, the cells of different tissues are different, and the cells of the same tissue are similar.

Of all plants, only algae have a homogeneous body, all its cells are similar to each other, and, therefore, algae do not have organs. Moreover, in unicellular algae, their entire body is one cell. The body of multicellular algae is called thallus. It is precisely because algae do not have tissues and organs that they are classified as lower plants.

All other plants are considered higher, since their body is divided into organs.

In the process of evolution, plants came to land. Air is less dense than water. If plants could float in water, then on the ground they simply had to creep, interfering with each other. But since plants need light for photosynthesis, it was more profitable to rise above the soil. In this case, other plants did not shade. As a result, plants developed mechanical tissue, which began to act as a support. Appeared stem- an organ that carries out the green photosynthetic organs of a plant ( leaves) as high as possible. In addition, there was a protective fabric.

In mosses, as the most simply arranged modern plants, such organs as the stem and leaves are observed. They don't have real roots yet. A number of moss species have only rhizoids- root-like formations. Unlike true roots, rhizoids do not contain different tissues.

Mosses are small plants. Many of them can absorb water not only with rhizoids, but also with the whole body. However, the further evolution of plants and their removal from places with excess moisture required the development of the root system.

Roots absorb water and minerals from the soil. There is little water in the air, but a lot in the soil. Aquatic plants had no problems with water, so they could absorb it with their whole body. Roots also anchor and hold the plant in the soil, allowing it to grow higher.

The appearance in plants of leaves, which are mainly responsible only for the synthesis of organic substances, and roots, which perform the function of absorbing an aqueous solution, led to the fact that the problem of transport of substances appeared. After all, organic matter is needed not only for leaves, and water - not only for roots. Water must be delivered to the leaves, and organic matter must be redistributed throughout the plant. Thus, conducting tissue has developed in plants. It passes in the form of bundles in the stem, and also goes into each leaf and root.

Leaves and stem form the escape plants. In addition to them, there are more on the run kidneys, which are rudimentary shoots. In other words, shoots of the next order can grow from one shoot of a plant.

Leaves, stem and root are called vegetative organs of a plant because they are not related to reproduction. However, plants have generative organs through which reproduction takes place.

The crown of the evolution of the plant world on Earth are angiosperms. In another way they are called flower. Their reproductive organ is flower. After pollination, the flowers develop fruit And seeds .

A flower is a modified shoot. It often happens that flowers are collected in groups - inflorescences. In this case, the inflorescence is a modified shoot.

The same organs of different plants can be very different from each other. So each type of plant has its own special form of leaves, the structure of the flower, as well as features in the external and internal structure of other organs. It is important that the same organs of different plants most often perform the same functions. That is, the leaves of most plants are responsible for photosynthesis, the roots - for the absorption of an aqueous solution and the fixation of plants in the soil, the stem - for the transport of substances and the removal of leaves to the light.

Plants are composed of organs such as vegetative and reproductive. Each of them is responsible for certain functions. Vegetative - for development and nutrition, and the reproductive organs of plants are involved in reproduction. These include flower, seed and fruit. They are responsible for the "birth" of offspring.

Vegetative organs

The appearance of vegetative organs was associated with the need to obtain nutrients from the soil. These include:

The root is the main organ of every plant growing in the ground.
The escape.
Stem.
Leaves are responsible for photosynthesis.
Kidneys.

The root is characteristic of all plants, as it holds them and nourishes them, extracting useful substances from the water. It is from him that shoots come, on which leaves grow.

When sowing seeds, the root germinates first. It is the main organ of the plant. After the root gains strength, a shoot system appears. Then the stem is formed. It has lateral shoots in the form of leaves and buds.

The stem supports the leaves and conducts nutrients to them from the roots. It can also store water in itself during a drought.

Leaves are responsible for photosynthesis and gas exchange. In some plants, they also perform other functions, such as storage of substances or reproduction.

In the process of evolution, organs change. This enables plants to adapt and survive in nature. There are new species that are more and more unique and unpretentious.

Root

The vegetative organ that holds the stem is involved in the process of absorption of water and nutrients from the soil throughout the life of the plant.

It arose after the advent of sushi. The root helped the plants adapt to changes on the ground. In the modern world, there are still rootless ones - moss and psilotoid ones.

In angiosperms, root development begins with the embryo entering the ground. As it develops, a stable organ appears, from which an escape sprouts.

The root is protected by a cap, which helps to receive useful substances. This is due to its structure and the content of a large amount of starch.

Stem

Axial vegetative organ. The stem bears leaves, buds and flowers. It is a conductor of nutrients from the root system to other organs of the plant. The stem of herbaceous species is also capable of photosynthesis, as are the leaves.

It is capable of performing the following functions: storage and reproduction. The structure of the stem is a cone. The epidermis, or tissue, is the primary cortex in some plant species. In peduncles, it is more loose, and in shoots, for example, in sunflowers, it is lamellar.

The function of photosynthesis is carried out due to the fact that the stem contains a chloroplast. This substance converts carbon dioxide and water into organic products. The supply of substances occurs due to starch, which is not consumed during the growth period.

Interestingly, in monocotyledonous plants, the stem retains its structure throughout the entire life cycle. In dicots, it changes. This can be seen in the cut of trees, where growth rings form.

Sheet

This is a lateral vegetative organ. Leaves differ in appearance, structure and function. The organ is involved in photosynthesis, gas exchange and transpiration.

Brush - in bird cherry, lily of the valley.
The cob is in corn.
Basket - chamomile or dandelion.
Umbrellas - at the cherry.
The shield is at the pear.

Complex inflorescences are several simple ones. Their origin is associated with the function of fertilization. The greater the number of flowers, the faster the pollen is transferred.

Fetus

The reproductive organs of plants primarily perform the function of reproduction. The fruit protects the seeds from their premature dispersal. They are dry or juicy. Seeds are formed inside the fruit, gradually ripening. Some of them are equipped with devices that help spread, for example, a dandelion is blown in the wind.

The main types of fruits:

Single-seeded with three layers - cherry, apricot, peach.
Multi-seeded with pulp - grapes.

A dry multi-seeded fruit happens with a partition - cabbage, and without it - peas. Oak is single-seeded.

The reproductive organs of flowering plants are arranged in such a way that seeds are distributed in several ways:

On water.
By air.
With the help of animals.
Self-dispersing.

Organs are arranged so that plants go through the process from the origin of roots to reproduction. The fruits have adapted to be carried by animals. This is provided by such devices as holds, parachutes, color accents and pleasant taste.

Seed

Knowing which plant organs are reproductive, you can understand exactly how they reproduce. The seed reproduces offspring and settles it for subsequent cultivation. It is made up of the peel, germ and nutrients from the stem.

The seed contains proteins, fats and carbohydrates. In fact, the embryo is the rudiments of the stem, root and leaves. It is the main part of the seed and comes with one or two cotyledons.

Seeds are also divided into several different types. In some, nutrients are in the endosperm, in others there are no tissues for reserves.

The seed coat protects against the effects of the external environment, wind and animals. After maturation, it helps to resettle the plant. Some species store nutrients in the peel.

Seeds are food for humans and animals. Their value on earth is quite high, like that of the fetus. These plant organs are involved in the life cycle of insects and animals, thereby providing them with food.

higher plants

In the plant world, everything is arranged so that organisms have the opportunity to grow constantly. Higher plants have organs such as shoots and roots. They differ in that in the process of fertilization, an embryo appears.

The reproductive organs of higher plants, interacting with the vegetative ones, change their life phases. They include four departments:

Ferns grow in moist places. These include horsetails and club mosses. Their structure includes root, stem and leaves.
Bryophytes are an intermediate group. Their body is made of tissue, but they do not have blood vessels. They live in both wet and dry soil. Moss reproduces not only by spores, but also by sexual and vegetative means.
Gymnosperms. The most ancient plants Most often they include coniferous trees and shrubs. They do not bloom, and their fruits form a cone with seeds inside.
Angiosperms. The most common plants They differ in that the seeds are securely covered under the skin of the fruit. Reproduction occurs in several ways. They differ in that they have female and male genital organs in the structure.

All these plants have been growing and developing on the earth for quite a long time. They differ from each other in the way of reproduction and the presence of certain organs. However, it should be noted that vegetation has a great influence on human life.

flowering plants

This species is the most numerous in the plant world. Flowering, or angiosperms, have been growing on the planet since ancient times. Ferns in the process of evolution were divided into many species.

The main reproductive organs of flowering plants are seeds. They are protected by the fruit, which helps them to be better preserved until distribution. Interestingly, this group of plants is the only one that can form multi-tiered communities. In turn, flowers are divided into two subspecies: monocotyledonous and dicotyledonous.

The main difference between flowering plants is that the reproductive organs of plants are a flower, a fruit and a seed. Pollination occurs through wind, water, insects and animals. In the structure of the plant there is a female and male growth, and double fertilization also occurs.

During germination, the seed is saturated with water and swells, then the reserve substances are split and provide energy for germination. From the embryo, a sprout appears, which later becomes a flower, tree or grass.

Gymnosperms

These include not only coniferous, but also deciduous trees. An amazing plant grows in the deserts of Kenya, which has only two large leaves. Its relative is ephedra. This is a gymnosperm plant that has small round berries.

pollination process

As you know, the reproductive organs of a plant include a flower, a fruit and a seed. In order for the process of fertilization to occur, pollination is necessary, which helps the appearance of offspring.

In angiosperms, male and female cells fuse. This is due to the cross transfer of pollen from one flower to another. In some cases, self-pollination occurs.

Helpers are needed for cross-pollination. First of all, these are insects. They feast on sweet pollen and carry it from flower to flower on their stigmas and wings. After that, the reproductive organs of plants begin their work. Flowers that are pollinated by insects are painted in bright and juicy shades. After coloring, they are attracted by the aroma. Insects smell the flower, being at a sufficiently large distance from it.

Wind pollinated plants are also equipped with special adaptations. Their anthers are fairly loosely spaced, so the wind carries the pollen. For example, poplar blossoms during the winds. This makes it possible to carry pollen from one tree to another without obstacles.

There are plants that are assisted by small birds in pollination. Their flowers do not have a sharp aroma, but are equipped with a bright red color. This attracts birds to drink the nectar, and pollination occurs at the same time.

plant evolution

After the advent of sushi nature has changed. Plants gradually evolved, and ferns were replaced by flowers, shrubs and trees. This was due to the appearance of the root system, tissues and cells.

Due to the diversity of the reproductive organs of angiosperms, more and more species and subspecies appeared. For reproduction, spores and seeds began to appear, in which germ cells were located.

Gradually, shoots, leaves and fruits appeared. After reaching land, the plants developed in two directions. Some (gametophytic) had two phases of development, others (sporophytes) passed from one cycle to another.

Plants adapted and developed. Spore species began to reach 40 meters in height. More and more reproductive organs of plants began to appear. Their evolution depended on the influence of the external environment.

An embryo was formed inside the seed, which, after fertilization and spraying, germinated. Getting into the ground, he ate useful substances and turned into a sprout.

The evolution of the fertilization process led to the emergence of angiosperms in which the seeds were protected by the fruit.

The value of plants for humans

The benefits of the natural world for people are priceless. Plants not only emit gases, salts and water, but also convert inorganic substances into those necessary for life. With the help of the root system, shoots and leaves, gas exchange occurs.

Green plants accumulate valuable organic substances in themselves, purify the air of carbon dioxide, while saturating it with oxygen.

Thanks to natural resources, people receive more valuable products necessary for life. Plants become food for animals and humans. They are used to treat various diseases, in the production of cosmetics.

Since the reproductive organ of the plant is the fruit and the seed, they have become indispensable in human nutrition. Berries that grow on shrubs are loved by almost everyone. Interestingly, coal and oil also originated from vegetation. Peatlands are the origin of algae and ferns.

The vegetative and reproductive organs of flowering plants play an important role in their life. They are responsible for nutrition, development and reproduction. When the life cycle ends, the seeds spread around and new plants sprout.

The organ is a separate part of the plant body, which has a certain structure and performs a number of functions. The body of higher plants can be divided into vegetative (from lat. vegetare - grow) and generative (lat. generate to generate, produce) organs.

Vegetative organs

These organs are the basis, without which the plant cannot exist, they perform vital functions. We list the vegetative organs (you will learn more about their functions in the following topics, now we will lay the foundation for their study):

Root
The escape

It consists of a stem with leaves and buds located on it. Write down for yourself such a "biological" formula: shoot = "stem + leaves + buds." You will understand in the following topics how useful this formula is for you;)

Stem

It has radial symmetry, grows upward, against gravity (negative geotropism). Leaves, flowers, fruits are formed on the stem.

All vegetative organs are capable of asexual (vegetative) reproduction. So, a cut branch of a plant placed in water begins to develop adventitious roots, and if such a branch is placed in the ground, creating optimal conditions, it will sprout into a new plant. The same possibilities open up at the root, which is divided in two, or at the leaf, placed in water.

Vegetative methods of plant propagation

Vegetative propagation was invented by nature, not by a gardener! However, the ways that mankind has thought of in relation to flowering plants cannot inspire. Many of them will seem like a miracle, so let's classify them!

Graft

It is carried out by close comparison of parts of different plants. The main condition for the parts to grow together is the fusion of the tissues of the vascular cambium. A rootstock and scion stand out.

A rootstock is a plant with a preserved stem and root system, on which a scion is "attached" - a grafted stem, leaves and flowers, as well as fruits.

Reproduction by corms

The increase in the number of corms occurs through the formation of several daughters (children). Corms form gladiolus, saffron and other plants.

Root tubers are, in particular, in dahlia, chistyak, sweet potato. A good gardener knows that from each bud on a tuber a new plant can begin to develop, so that in order to propagate the desired variety, the tuber is cut into several pieces before planting according to the number of eyes.

In order to propagate plants with root crops (beets, radishes, carrots), the leaves of root crops are cut off in such a way as to leave petioles 1-2 cm long and an apical bud from which a new plant will develop.

A small area of the rhizome is quite enough for vegetative propagation, the main thing is that this area contains a kidney. Rhizome plants are extremely fast spreading in the territory, the annual growth of one rhizome of couch grass can reach 30 - 40 cm. landslides.

Reproduction by whiskers (stolons)

A very effective method of reproduction (for example, one specimen of strawberries in two years gives rise to an average of 200 new plants) and resettlement (a strawberry bush inhabits 1.5 m 2 of the surrounding area per year).

A layer is called an annual shoot, pressed to the soil and sprinkled with earth in this place. In the sprinkled part, adventitious roots develop from the shoot, and a new plant is formed.

Quite often, cuttings are used for artificial vegetative propagation - segments separated from the parent plant. Depending on the place where the cutting is taken, there are: root, stem and leaf cuttings.

Every year, daughter bulbs, which are also called babies, can be isolated from the bulb. Several children can be separated from the mother bulb at once.

This method is used in spring or closer to autumn, in relation to shrubs to increase the planting material of the desired varieties of shrubs. The bush must be divided so that each part has above-ground shoots and its own root system.

generative organs

The main function of the generative organs is the seed reproduction of plants, or sexual reproduction. There are three generative organs:

Flower

During sexual reproduction, gametes fuse to form an embryo. The organ of sexual reproduction of angiosperms is a flower, which is covered in detail in the corresponding topic.

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