Spore plants have mastered the Earth by the first. They belong to the higher class, since they have tissues and organs, unlike algae. Spore plants are propagated by dispute or with their help are adapted to new environmental conditions.
Spore plants include representatives of mossy, horsetail and plaunid, fervor, some lichens and mushrooms, blue-green algae.
Life cycle of spore plants
Life cycle of spore plants the alternation of the likely and sexual generations. That is, gametophyte and sporophyte alternate. On the sporophyte there are only organs that provide asexual reproduction, and on the gametophyte sexual.
These plants as a result of evolution changed. So the diploid and haploid groups appeared. The first includes fern with horsetails and plans. These representatives of Flora Hametophyte almost disappeared, it looks like a process. And by the haploid branch, scientists are ranked by mosses, their gametophyte is developed.
It is clear that the organs of sexual reproduction develop only on the gametophyte. Male plants have anteridia oval processes, inside of which spermatozoa ripen. Female genital organs archegony. There is an egg inside them. For fertilization to occur, the male gender must penetrate the female. So that the sperm can get inside the archegony, he needs water. An embryo develops from a fertilized egg. Over time, he becomes an adult plant from a likely generation and multiplies with spores, which is waiting in the wings in sporangia.
Each spore plant has a predominant phase. Mosses have a gametophyte. In lichens, blue-green algae, horsetails and plans, this is sporophyte.
Higher spore plants
Plants of this department are found in almost all climatic zones, but their larger number is in the tropics, because there are the most favorable conditions for reproduction.
Fernowshaped perennial herbaceous plants. There are also trees with vines in this department. There are two forms epiphytic and water. Epifite ferns are often used as decoration of apartments and houses. Among them nephrolepis.
Ferners generate food in the process of photosynthesis, they “pump” all nutrients and moisture from the ground. Burners breathe oxygen.
Representatives of the department have an escape with subordinate roots and several types of fabrics: cover, conducting and mechanical. Almost all ferns have a rhizome hidden under the soil, which is often poisonous for a person. Plant leaves are called viyi. They can be both whole and dissected. In the rudiment of the sheet will be turned into a spiral, over time it straightens up. On the back of the sheet are sporangia, in which there are disputes. With the help of these spores and the creation of the kidneys, rooting of shoots, an asexual reproduction occurs. Sexual with gametes.
The environmentforming component
Thickets of fern are a house for various arthropods and mollusks, in them birds create nests. In the roots of water forms, fry and representatives of invertebrates hide from predators. Fish lay caviar in their rhizomes. Some insects even feed on fern leaves, among them a twopoint leafist.
The ancient representatives of the Portnikovs also contributed to nature, creating entire layers of coal. Today this material is used in the chemical industry.
This group belongs to about 30,000 species. This includes representatives of the department of Mookhovid, liver, antocerot mosses, mossy. Mokhoma includes a class of leafstble and sphagnum. These two classes should be considered separately.
Mosses grassy plants whose height varies from 2 mm to 30 cm. Some water mosses can be longer and reach 1, 5 meter height. These are usually perennial forms. Mokhoma prefer places that are almost devoid of light. Mosses can be found next to reservoirs.
Mosses get food using photosynthesis. By the type of power, they are autotrophs. Their bodies absorb water perfectly. These plants are breathing.
The body of the plant can consist of a layword or a stem with leaves. Mosses have no roots as such, but most species have risoids. The bodies of the mossy are formed using photosynthetic tissue, there is no conductive fabric. The rest of the types are almost not expressed.
When it comes to ash propagation, mosses share their laywords or parts of the stem. Some types of kidneys have. Sexual reproduction occurs using gametes. After their merger on the gametophyte, sporophyte immediately begins to develop. This is usually a box in which disputes ripen. The wind spreads them on the ground and, having fallen into the point of purpose, they turn into a thread at which buds form after time. From the kidneys, layouts are formed.
Class of leafstable mosses
This class includes Kukushkin Lenon. Grows in wet forests of a moderate climate belt. Among the habitat is represented by groups.
The length of the stem is about 30 cm. It consists of dead cells that conduct nutrients and accumulate moisture in themselves. Instead of the roots of the moss of risoids, they are located at the bottom of the stem. These organs absorb minerals from the soil. Leaves accumulations of cells involved in photosynthesis.
Green Kukushkin Lenon representative of the sexual generation. This moss is a separate plant. Gametes are formed at the top of the gametophyte.
The class of sphagnum mosses
One of the representatives of the Sfagnovs is sphagnum. This moss and its relatives can be found in the northern hemisphere. This is usually an accumulation of individuals.
The sphagnum has no roots, the plant absorbs moisture with the whole body. Small leaves that are located on the stem are formed by cells of 2 types. The cells that are engaged in photosynthesis look like a grid, where organics are constantly transported. There are dead cells between them, which are needed to create a moisture supply.
The environmentforming component
As the sphagnum develops, part of it is under young leaves, gradually dies and decomposes. This process occurs in an airless environment, because the moss is converted into peat.
This is a plant department, which includes more than 1000 species. Most of all the Plaun is a pinshaped.
Plaunovic perennial plants, often evergreen. The shoots of the plans are laid down and branching, they strengthen their position in the soil with the help of subordinate roots. The leaves are simple, quite small, only one vein. The shoots are located spikes with spores. Conducting fabric is very well developed, water supply elements tracheids.
It is interesting that with ash propagation, a density of shoots or a stem can occur. But usually spikes with spores are formed on the shoots. These sporophytes are covered with leaves that resemble the scales. Disputes ripen on it. After they are released, they begin to turn into 2-mm embells-gametophytes. Next, sexual reproduction occurs.
The meaning of the plans in the nature and life of man
This section of plants experienced its flowering in the coal period. Now there are not so many species of plains left. 20 species of plas that grow in Eurasia are listed in the Red Book. The Plaun-Baranian is completely fatally to venue (a list of poisonous plants of Eurasia). Many species of antiquity participated in the formation of stone coal.
The department is horsetical
This group includes 32 types of vascular plants. All of them belong to the genus of horsetails. Only 12 species can be found on the territory of Eurasia. Pherdiology studies these bizarre plants.
Horsetail-grassy plants, whose height varies from 2 cm to 2-3 m. Representatives of the department can be found both in a temperate climatic zone and in tropical latitudes.
The stems of horsetail are horseman, they consist of internodes, participate in the process of photosynthesis. Thuts are on the stems, they look like small scales. In the soil there is a rhizome with many outgrowths that can turn into tubers. There are reserves of minerals. With the help of these tubers, you can also produce vegetative propagation.
Horcass has 2 type of shoots: generative and vegetative. There are no chlorophyll in the first, they are painted in brown, they cannot branch. At the top of such a shoot, spikelets with spores are formed. The germ of them then grow, right on which small horsetails will appear very soon. After the disputes are scattered, the shoots die off. The second type of shoots branching.
The meaning of horsetails in nature and human life
Some types of horsetails were transformed into deposits of coal. Rosa, wild boars and deer, muskrats and some species of waterfowl feed on horsetails. But for people horsetails are poisonous, since they have quite a lot of silica.
Horsetails are used in evidencebased medicine to prevent bleeding and to ensure the diuretic effect.
Blue-green algae (lower spores)
Blue-green algae or cyanobacteria-a department based on prokaryotes. Algae cells contain chlorophyll and you can find them only in the aquatic environment. Moreover, these algae can survive both at very low and at very high temperatures. These algae differ from other spores in that they bloom. This happens in late autumn and summer.
History of detection
Blue-green algae are the oldest group among autotrophs and organisms in general. The remains dating 3 billion years, the first cyanobacteria were found in dentists. These are lime formations, they have the wrong form.
Cyanobacteria does not have a body, it is replaced by a layout. Cyanobacteria has 2 types of cells: spherical and ellipsoid. The second type of cell as if compressed on the sides. Usually cells are fragmented, but they can form colonies and threads.
Meaning in human life and nature
Cyanobacteria played a huge role in the evolution of a living shell of the Earth. These prokaryotes were able to create a new type of photosynthesis, during which oxygen is released. So, blue-green algae instead of hydrogen sulfide began to use water, which ensured the appearance of heterotrophs. But some of these prokaryots also record nitrogen in the atmosphere, transforming it into a suitable form for living organisms. These species have learned to separate the functions of their cells, because nitrogenfixing enzymes cannot perform work in the presence of oxygen.