Features of the structure of sporophyte in fern. Ferns: Signs, Building, Reproduction
Ferns are commonly common over the entire globe, starting with the desert and ending with swamps, rice fields and brackish reservoirs. Most diverse - in tropical wet forests. There they are represented as tree shapes (up to 25m in height), and grassy and epiphets (growing on the trunks and branches of trees). There are species of ferns long just a few millimeters.
The structure of ferns
The usual fern plant that we see is an affordable generation, or sporophyte. Almost all ferns is long-year, although there are few species that have annual sporophyte. Ferns are apparent roots (only in some species they are reduced).
Ferns - Pictures
The foliage, as a rule, by mass and sizes prevails over the stem. The stems are reprehension (trunks), creeping or curly (rhizomes); Often branched. Our forest ferns (Ostrichnik, Orlyak, Male Piece) have a well-developed rhizome with numerous apparent roots. Over the Earth there are only large peristrastic leaves - Wii.
The young leaf is coated altitude, as it grows it straightens. In some species, the development of the sheet occurs within three years. Ferns leaves are growing with their top, like stems, which indicates their origin from the stem. In other groups of plants, the leaves are growing from the ground.
In terms of its size, they can be from a few millimeters, up to three or more meters long and most species perform two functions - photosynthetic and dispute.
Reproduction of ferns
On the bottom side of the sheet, brown tubercles are usually located - seasons with sporangies located in them, covered on top of a thin film. In the sporangies as a result of meiosis, haploid disputes are formed, with the help of which the fermentation is reproduced.
From the controversy of the forest fern, which has fallen into favorable conditions, a haploid ratio, a gametophyte, a small green plate of the heart-shaped form, is up to 1 cm in diameter. The outflow increases in shaded, wet places and is attached to the soil with the help of rhizoids. On the underside of Gametophyte, Aniardia and Archegonia are developing.
The "conquest" of Sushi ferns turned out to be incomplete, since the generation of GaMetophyte could exist only with the abundance of moisture and shadow, and an aquatic environment is needed for the merger.
Horschi - structure
Horsetail - Photo Chests are presented mainly by fossil forms. They arose during Devon and experienced flourishing in the coal period, reaching a wide variety of forms - up to the giants height in 13m.
Modern horsetails are about 32 species and are represented by small forms - no more than 40cm height. They are found from the tropics to the polar regions, with the exception of Australia, and can live in both swampy and dry areas. Some species have in the epidermis of silicon deposits, which gives them a roughness.
Reproduction and development of horsages
Spiritophyte in the horsetail consists of a horizontally branched underground stem - rhizomes, from which thin, branching roots and segal overhead stems are departed. Some side branches of rhizomes are capable of forming small tubers with a nutrient reserve.
The stem contains numerous vascular beams located rings around the central cavity. On the stems, as well as on the rhizome, nodes that give them a segmental structure are clearly expressed.
From each node, a mutsky of secondary twigs is departed. The leaves are small, wedge-shaped, are located too with mutters, cover the stem in the form of a tube. Photosynthesis occurs in the stem.
In addition to the assimilant stalks, the horsettle of the field there are still non-brown sporing sponshles, at the ends of which are developing sporangies collected in spikelets. They are formed disputes. After ravings, the sprouts die away, and they grow green branchy (vegetative, summer) shoots to replace them.
Plaues - Building
Plans were widespread at the end of Devonsky and in coal periods. Many of them were high tree plants. Currently, a minor, compared with the past, the number of species (about 400) is all small plants - up to 30cm in height. In our latitudes, they are found in coniferous forests, less often - on the marsh meadows. The main mass of the plauen - residents of the tropics.
We have the usual view of the plane concupilated. It has a stewing stem, from which needle-branched side shoots will be wound up vertically up. He has the leaves - thin, flat, are located on the helix, densely covering the stem and side sprigs. Plain growth occurs only at the point of growth, as Cambines in the stem is missing.
Plane one - Photo Reproduction of Plauan
At the top of the stem, there are special leaves - sporesophilles collected in gates. Outwardly, he resembles a pine cone.
The germinating dispute gives a switch (Gametophyte) that lives and develops in the ground for 12-20 years. It does not have chlorophyll and feeds with mushrooms (mikoriza). The change of sexual and blessing generations at the horsages and planes occurs in the same way as ferns.
Fossil fern formed powerful coal layers. Stone coal is used as fuel and raw materials in various industries. It is obtained from gasoline, kerosene, combustible gas, various dyes, varnishes, plastics, aromatic, medicinal substances, etc.
The meaning of ferns, horsages and plane
Modern fernames play a prominent role in the formation of plant landscapes on Earth. In addition, a person uses chests as a diuretic as an indicator of soil acidity. Due to the stiffness of the stems associated with silicon deposits in the walls of the cells, the chests were used to polish furniture, cleaning dishes.
Plain disputes are used in medicine as suproes, male shields - like anthelnogon. They are consumed for the treatment of tobacco dependence, alcoholism and eye diseases. Some species of fernation are bred as decorative (adiantum, asplenium, nephrolapp).
Since the Gametophyte of Plain develops very slowly (12-20 years), these plants should be protected.
Ferny-shaped is a group of dispute plants that have conductive tissues (vascular beams). It is assumed that they originated more than 400 million years ago, in the Paleozoic period.
The ancestors consider rhinophytes, but fern plants in the process of evolution acquired a more complex system of structure (leaves appeared, root system).
Signs of fernames
For fern, the following signs are characteristic:
Variety of shapes, life cycles, structure system. There are three hundred births and approximately 10 thousand species of plants (the most numerous disputes).
High resistance to climate change, humidity, the formation of a huge number of disputes - the reasons that led to the resettlement of fernation throughout the planet. There are found in the lower tiers of the forest, on a rocky surface, near the marshes, rivers, lakes, grow on the walls of abandoned houses and in rural areas. The most favorable conditions for fernyst plants are the presence of moisture and heat, so you can meet the greatest variety in the tropics and subtropics.
All fern for fertilization need water. They pass two periods in the life cycle:
- Prolonged mutib (sporophyte);
- short sex (Gamenaophyte).
When the dispute enges on the wet surface, the germination process is immediately activated, the field phase occurs. Gametophyte is attached to the Earth with the help of rhizoids (formation similar to the roots, is needed for nutrition and attachment to substrate) and starts an independent growth. The newly formed sprout forms men's and female genital organs (Anteria, Archegononia), they are formation of weights (spermatozoa and eggs), which merge and give life a new plant.
During the disclosure of the sporangia (the place of maturation of dispute cells) a lot of dispute is poured, but only their part survives, because for further growth, a wet environment is needed and a shadow area.
Ferns curly on the ground can breed vegetatively, the leaves, in contact with the soil, with sufficient humidity give new sprouts.
Fernic stems have a variety of formsBut inferior in size foliage. When the stem on the top carries the leaves, it is called a trunk, it is equipped with a branching root, which gives the stability of tree fern. Curly stalks are called rhizome, can be forgotten at considerable distances.
Fern never bloom. In ancient times, when people did not know about the dispute of reproduction, there were legends about the fern flower, which had magical properties, who would find him, would acquire an unknown force.
Progressive features in the structure of fern
Appeared rootsThey are apparent, that is, the initial root does not function in the future. Replaced with roots sprouted from the stem.
Leaves have no typical structure, this is a combination of branches located in the same plane called frond. They are chlorophyll, at the expense of which photosynthesis occurs. Wii also serve to reproduce, on the back of the sheet there are sporangies, after their ripening, disclosure and rash dispute occurs.
Adults Flyless - diploid organisms.
Classification of fern-like classes
Real fern - The most numerous class. Representative male shield - A perennial plant, reaches a height of up to 1 m. Rhizome thick, short, covered with scales, there are leaves on it. Grows on wet soil in mixed and coniferous forests. Orlyak ordinary It dwells in pine forests, reaches large sizes. Quickly multiplies, it takes good enough, so it can occupy significant areas if used in parks or gardens.
Helds - Herbatous ferns, grow from several centimeters to 12 meters ( horsetail giant), In this case, the diameter of the stem is about 3 cm, so to develop them to use other trees as a support. The foliage is modified to scales, the stem is evenly divided by nodules on the inter-oil sections. The root system is represented by pressing roots, in the soil is also part of the rhizomes, which can form tubers (organs of vegetative reproduction).
- belong to the ancient types of plants, which inhabited our planet in the coal period. There is a stem, up to the middle of immersed in the soil, the roots are apparent. Now they gradually die, occur only in tropical belts. Possess huge bunk leaves, up to 6 meters long.
Uzhovnikovy - Ground herbaceous plants up to 20 cm high (there are exceptions that reach 1.5 m long). Representatives have a fat root that does not give branches. Rhizome, for example, the grazed worker is alone short, not branched, and chervec-creek - Curly, spreads on the ground.
- aqueous ferns (inhabit the reservoirs of Africa, southern Europe), which have a root for mounting to a very moistened soil. They are parallers, male and female gamemarketophytes are developing separately. After the ripening, the adult disgrace dies, and the dots fall on the bottom, of which spores will come out and rise from the depths of the water surface, where fertilization occurs. Used like plants for aquariums.
The meaning of fern plants
The remains of ferns gave deposits of minerals: stone coal, which is widely used in industry (as fuel, chemical raw materials). Some species contribute like fertilizer.
Ferns are food and house for lower animals. Select oxygen during photosynthesis.
The beauty of plants attracts landscape designers, so they are grown as scenery. Some species can be used in food (orlyak foliage).
Features of the structure of ferns: As a rule, ferns grow in the forests of a moderate climatic belt. Their body consists of a modified escape located under the ground - rhizome. Over the earth is visible only leaves. This is the external structure of the fern. The underground structure of the fern is also represented by a system of pressing roots, which the beam is departed from the modified escape. But the fossil shapes of fernsoids are not at all similar to their modern conifers. Along with herbs, these were small shrubs and gigantic trees reaching a height of several tens of meters.
The practical value of the fern:Fernic-shaped used for the production of soap, glass and decorative purposes.
2. . What is food and digestion? Describe the chemical composition of food.
The digestion is the process of splitting complex organic substances (proteins, fats, carbohydrates) to simple, which can be absorbed into blood and lymph and assimilated in the body.
Food is the process of absorption of food with alive organisms to maintain the normal flow of physiological processes of life, in particular, to replenish the stock of energy and the implementation of growth and development processes.
Chemical composition of food:proteins, fats, carbohydrates, mineral salts, H 2 O.
3. Practical task.
Ticket number 12.
Describe class crustaceans. Describe their value in the nature and life of a person.
The meaning of crustaceans in the nature and life of a person
Describe the structure of the digestive system: digestive organs and their functions.
The digestive system consists of the following organs and departments:
· Rota cavity with self-saline glands;
· Harness; esophagus region;
· Stomach;
· Thin and thick intestines; liver;
· pancreas.
Digestive organs and their functions:
Digestive channeldigesting food, suction of foods in blood and lymph;
Digestive glands: selection of digestive juice;
Gastric mucosa: generating mucus for moisture wall of the channel of the digestive glands;
Muscular shell: moving food to the digestive tract;
Outer shell: performs a protective function;
Abdominal cavity: protection of digestive organs;
3. Practical task
Ticket number 13.
1. Open planetary value of plants.
The planetary value of plants is that in the early stages of the development of life on the planet, they, due to the ability to photosynthesis, changed the gas composition of the Earth's atmosphere towards a significant increase in oxygen in it.
What are the features of digestion in the oral cavity and stomach?
The features of the digestion are that in the oral cavity there is a process of grinding food and chewing food, and the process of digesting food decomposition is like a digestion of food.
3. Practical task.
Fern-like (PTEROPHYTA) - Department of higher plants, known from Devon and occupying an intermediate position between plyphithi and gone. Unlike mossoid Ferns have conductive tissue delivering water and nutrients to all organs. Ferns have well-developed leaves and stem, many - rhizome (with pressing roots), but there are no flowers or seeds.
Like all higher plants, the alternation of two generations with a clear predominance of the crucible ( sporophyte). Sporophytic fern is a grassy or tree plant with large cereal leaves, spirally cooled in the kidneys. Characterized by the extreme diversity of forms; They are underground and overhead, reprehensive and curly, simple and branches. The length of the stems of modern ferns varies from several centimeters to 25 m. The main support function of the stems are performed by cells of the cortex. There are no cambiums in the company, therefore they do not form annual rings, and growth and strength are limited. Conductive fabric is not as perfect, like in seed plants: So, xylem in most of them are not formed by vessels, but by tracheids, flora - synovoid cells, rather than straight tubes.
Ferns have no real leaves. But they made the first steps in their direction. The fact that the fern resembles a sheet is not a sheet at all, but by its nature - a whole system of branches, and even located in the same plane. So it is called - a flatter, or a wija, or, one more name, - an extraordort. Despite the lack of leaf, the fern is a leaf plate.
Ferns breed Disputes and vegetatively (Viyami, rhizomes, kidneys, Afflebia, and so on). In addition, sexual reproduction is characterized for ferns as part of their life cycle.
On the bottom of the sheet ripen sporophyll, sometimes collected in groups - saruses. In some ferns, leaves or their individual fragments are differentiated into green and sporing. The disputes fall on the ground and gemmatophytes (overtakers). This is a gentle short-lived plate plate diameter with a diameter of about 1 cm with genuine organs scattered on the surface - alteridia and Archeganiain which gametes ripen. The outflow is rooted by unicellular rhizoids and is capable of photosynthesis. Gamets arise by mitosis from maternal cells. Archegonia is isolated chemicals (for example, apple acid), "attracting" spermatozoa (hemotaxis). Fertilization is usually crossed. Polysegutic spermatozoa from anteridy with drop-headed water falls in Archegonia; One of them fertilizes the egg, as a result of which the zygote is formed. The zygota is intensively divided, sprinkling right in Archegonia to a new sporophyte; The outline fades and dies.
Spores can also multiply in vegetative way. On the leaves lying on Earth, new plants can be formed, rooting then in the soil.
The Fern Department includes one class, divided into eight subclasses. Contemporary fernsoid about ten thousand species (300 genera).
The most extensive modern subclass - real fern.
Real ferns are seased worldwide; Especially a lot of them in the tropical rain forests, where they make up an important element of mountain vegetation. In a temperate belt, they grow most often in shady forests, deep ravines and swamps. Some types of fern drought-resistant and occur on dry stony slopes and even in the desert. Their leaves are covered with a layer of wax, dense hairs or scales that prevent water loss. Leaves of other species consist of one cell layer; The lack of devices for drying protection limits their distribution by places constantly enveloped fog. Some ferns fall on the branches of trees.
The low, dense fern, reaching the height of 10-20 cm. It has a thick, short rhizome.
The leaves are dim green, on both sides are covered with brown flakes and long hairs with a thick, brilliant cushion. Sheet plate, equal to the cutter or longer, in the outlines are oblong - lanceal, twice peristrasty.
Sources are located along the edge of the final blades close from each other and merge. The coathouse is a wedding, wavy, dissected on the hair-like shares, attached under the dura. Saruses ripen in the second half of the summer - early autumn.
On the territory of Karelia, it is rarely found, more often in the southern regions in the cracks of the rocks.
A low-length fern, a height of 10-30 cm, with a short, thick brown rhizome, on which the bundle is located leaves.
The leaves are naked, thin, in the outlines are altage tramen, pointed on the top, to the base of the narrowed, twiceperistracted. Puffs brittle, usually shorter than plates. Quite often found on rock outcrops almost all over the territory of Karelia, in the north - rarely. Poison plant, especially disputes containing sinyl acid. Young leaves have the smell of almond.
A characteristic peculiar feature is a clear separation of vegetative and sporing leaves. In the spring, large green leaves develop on the rhizome in a funnel-shaped outlet, and 2-3 brown sporing sheets of smaller sizes appear in the center of the funnel.Vegetative leaves are twice peristracted, with a short cushion, on the top of the pointed, to the base gradually narrowing.Sporied winter leaves, one day. Curly, with the segments directed upwards.
Ostrichnik has a thick creepy (rhizome of black and brown color. Plant height 60-100 cm. It occurs throughout Karelia in places - in raw shaded shady forests, more often in sprues on the shores of the streams, forming usually almost clean thickets. The decoction of rhizomes in folk medicine is used as anthelnogon Means. Finds applied as an insecticide. As a decorative plant, it may be divorced for landing in shaded and wet places of gardens and parks.
A relatively thick rhizome of a male fern is located at a slight depth in the soil. The top of it is somewhat towers over its surface and annually takes a bundle containing 5-7 leaves. The leaves are large, twiceful, with a height of 40-80 cm. Finite segments - with stupid teeth, never ends needle. Cuthes are short, thick covered with brown films.Vegetative and sporing leaves do not differ in shape, magnitude and color.
The economic significance of ferns is small. Some species are decorative plants in Orangery. The economic significance of ferns is not so large compared to seed plants. Food application have such species as an ordinary Orlyak, an ordinary ore, cinnamon Osmund. Some types of poisonous. The most toxic fern growing growing in Russia are representatives of the Plotpteris (Dryopteris), the rhizomes of which contains the derivatives of the floraoglutinate. Extracts from shields have anthelmintic effects and are used in medicine. Wija some shields are widely used as a green component of floristic compositions. Orchids are often grown in a special "peat" of the densely intertwined thin roots of the pistow.The trunks of tree ferns serve in the tropics by building material, and in Hawaii their starchy core is used in food.