Biomass of the Earth, infographics. Mass of people, plants, animals, fungi, bacteria and viruses

Bacteria. These are single-celled prokaryotic organisms. Their size ranges from 0.5 to 10-13 microns. Bacteria were first observed under a microscope by Anthony van Leeuwenhoek in the 17th century.

A bacterial cell has a membrane (cell wall) similar to a plant cell. But in bacteria it is elastic, non-cellulose. Under the shell there is a cell membrane, which ensures the selective flow of substances into the cell. It protrudes into the cytoplasm, increasing the surface of membrane formations on which many metabolic reactions take place. A significant difference between a bacterial cell and the cells of other organisms is the absence of a formed nucleus. In the nuclear zone there is a circular DNA molecule, which is the carrier of genetic information and regulates all life processes of the cell. Of the other organelles in bacterial cells, only ribosomes are present, on which protein synthesis occurs. Prokaryotes lack all other organelles.

Rice. 59. Various forms of bacteria

The shape of bacteria is very diverse and forms the basis of their classification (Fig. 59). These are spherical - cocci, rod-shaped - bacilli, curved - vibrios, twisted - spirilla And spirochetes. Some bacteria have flagella that help them move. Bacteria reproduce by simply dividing a cell into two. Under favorable conditions, a bacterial cell divides every 20 minutes. If conditions are unfavorable, further proliferation of the bacterial colony is stopped or slowed down. Bacteria do not tolerate low and high temperatures well: when heated to 80 °C, many die, and some, under unfavorable conditions, form disputes- resting stages, covered with a dense shell. In this state they remain viable for quite a long time, sometimes several years. Some bacterial spores can withstand freezing and temperatures up to 129°C. Sporulation is characteristic of bacilli, for example pathogens anthrax, tuberculosis.

Bacteria live everywhere - in soil, water, air, in the bodies of plants, animals and humans. Many bacteria according to the way they feed are heterotrophic organisms, i.e. they use ready-made organic matter. Some of them, being saprophytes, destroys the remains of dead plants and animals, participates in the decomposition of manure, and promotes soil mineralization. Bacterial processes of alcoholic and lactic acid fermentation are used by humans. There are species that can live in the human body without causing harm. For example, E. coli lives in the human intestines. Certain types of bacteria, settling on food products, cause their spoilage. Saprophytes include bacteria of decay and fermentation.

In addition to heterotrophs, there are also autotrophic bacteria that can oxidize inorganic substances and use the released energy for the synthesis of organic substances. For example, soil azotobacteria enrich it with nitrogen, increasing fertility. On the roots of leguminous plants - clover, lupine, peas - you can see nodules containing such bacteria. Autotrophs include sulfur bacteria and iron bacteria.

Another group of microorganisms belongs to prokaryotes - cyanobacteria. Cyanobacteria are autotrophs, have a photosynthetic system and the corresponding pigments. That's why they are green or blue-green in color. Cyanobacteria can be solitary, colonial, or filamentous (multicellular).

They are similar in appearance to algae. Cyanobacteria are common in water, soil, hot springs, and are part of lichens.

Mushrooms. This is a group of heterotrophic organisms that has characteristics similar to plants and animals.

Like plants, fungi have a cell wall, unlimited growth, they are immobile, reproduce by spores, and feed by absorbing nutrients dissolved in water.

Like animals, fungi are not able to synthesize organic substances from inorganic ones, do not have plastids and photosynthetic pigments, accumulate glycogen rather than starch as a reserve nutrient, and the cell membrane is built from chitin, not cellulose.

That is why mushrooms are classified into a separate kingdom. The kingdom of mushrooms unites about 100 thousand species that are widespread on Earth.

Rice. 60. The structure of mushrooms: 1 - mucor; 2 - yeast; 3 - penicillium

Mushroom body (Fig. 60) - thallus consists of thin threads - hyphae. A collection of hyphae is called mycelium or mycelium. Hyphae may have septa, forming individual cells. But in some cases there are no partitions (in mucor). Therefore, fungal cells can contain one or many nuclei.

The mycelium develops on the substrate, while the hyphae penetrate into the substrate and grow, branching repeatedly. Mushrooms reproduce vegetatively - by parts of mycelium and spores that mature in specialized cells - sporangia.

Mushrooms are divided into two classes: lower and higher mushrooms.

1. Lower mushrooms often have multinucleate mycelium or consist of a single cell. Representatives of lower fungi are mold fungi: mucor, penicillium, aspergillus. In penicillium, unlike mucor, the mycelium is multicellular, divided into partitions. Molds develop in the soil, on wet foods, in fruits and vegetables, causing them to spoil. One part of the fungal hyphae penetrates into the substrate, and the other part rises above the surface. Spores mature at the ends of vertical hyphae.

Yeast - These are lower unicellular fungi. Yeast does not form mycelium and reproduces by budding. They cause alcoholic fermentation, decomposing sugar in the process of their life activity. They are used in brewing, baking, and winemaking.

2. TO higher mushrooms relate cap mushrooms. They are characterized by multicellular mycelium, which develops in the soil and forms on the surface. fruiting bodies, consisting of tightly intertwined hyphae in which spores mature. The fruiting bodies consist of a stem and a cap. In some mushrooms, the lower layer of the cap is formed by radially arranged plates - this is lamellar mushrooms. These include russula, chanterelles, champignons, toadstool, etc. Other mushrooms have numerous tubes on the underside of the cap - these are tubular mushrooms. These include porcini mushroom, boletus, boletus, fly agaric, etc. Fungal spores ripen in tubes and on plates. Often the mycelium of the fungus forms mycorrhiza, growing by hyphae into plant roots. The plant supplies the fungus with organic nutrients, and the fungus provides mineral nutrition to the plant. Such mutually beneficial cohabitation is called symbiosis. Many cap mushrooms are edible, but some are poisonous.

1. Saprophytic mushrooms feed on dead organisms, organic debris, food products, ripened fruits, causing them to rot and decay. Saprophytes include mucor, penicillium, aspergillus, and most cap mushrooms.

Fungi, along with bacteria, play an important role in the cycle of substances in the biosphere. They decompose organic substances, mineralize them, and participate in the formation of a fertile soil layer - humus. The importance of mushrooms in human life is also great. In addition to being used as food, medicines are obtained from mushrooms - antibiotics (penicillin), vitamins, plant growth substances (gibberellin), enzymes.

Lichens. This is a unique group of organisms, representing a symbiosis of a fungus and unicellular algae or cyanobacteria. The fungus protects the algae from drying out and supplies it with water. And algae and cyanobacteria, through the process of photosynthesis, form organic substances that the fungus feeds on.

Lichen body - thallus (thallus) consists of fungal hyphae, among which are unicellular algae. The surface layer of lichen is formed by densely woven hyphae, and the lower ones are more sparse. Green algae are located among the sparse network of hyphae.

Such structural features of the lichen allow it not only to receive nutrition from the soil, but also to capture moisture and dust particles that settle on the thallus from the air. Therefore, lichens have a unique feature - they can exist in the most unfavorable conditions, settling on bare rocks and stones, tree bark, and house roofs. They are called “pioneers” of soil formation, since, by “inhabiting” rocks, they create conditions for the subsequent settlement of plants. The only one a necessary condition clean air is essential for the life of lichens. Therefore, they serve as indicators of the degree of air pollution.

Lichens reproduce vegetatively - by parts of the thallus and algae cells. They grow very slowly.

By appearance lichens are divided into three groups: crustose (scale), leafy and bushy (Fig. 61).

crustose lichens The thallus adheres tightly to the substrate, from which they cannot be separated. They are completely satisfied with a small amount of water that falls in the form of precipitation or is in the atmosphere in the form of vapor. They settle on tree trunks and stones.

Rice. 61. Lichens: A - structure (1 - green algae cells; 2 - fungal hyphae); B - variety: 2 - cortical, 3 - leafy, 4 - bushy

Xanthoria - Wall goldenrod is often found on aspen bark, board fences and roofs. Parmelia - a lichen with large lobes of gray-blue color, lives on the bark of pine trees and dead branches of spruce.

Foliaceous lichens can be found on the bark of trees, soil where there is no grass. They are attached to the substrate with the help of thin outgrowths of the thallus.

Peltiger - a gray-green lichen with black veins below, growing on the soil in damp places.

Fruticose lichens have a highly branched thallus. They grow mainly on soil, stumps, and tree trunks. They are attached to the substrate only by the base.

Iceland moss- a gray-yellow lichen with strongly curved narrow outgrowths of the thallus. Contains a lot of vitamin C, used for scurvy in the North. Reindeer moss, or reindeer moss, occupies large spaces in the tundra and serves as the main food for reindeer. These are graceful bushes consisting of thin, highly branched stems. When dry, it becomes brittle and crunches underfoot. It also grows in dry pine forests. Krasnogolovka- gray-green small, 3 cm, tubes, with a red edge or balls (heads) along the edge. Grows on old stumps. bearded man forms long hanging clumps, settling on trees in humid forests, most often on spruce trees.

Being autoheterotrophs, lichens create organic substances through the process of photosynthesis in places inaccessible to other organisms. At the same time, they mineralize organic matter, thereby participating in the cycle of substances in nature and playing an important role in soil formation.

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§ 50. System of classification of living organisms§ 52. Plants, their structure. Vegetative organs

Life has existed on Earth for billions of years. At first these were the simplest organisms, which consisted of a single cell. Over time, their structure became more complex, and multicellular organisms appeared. During the process of evolution, the diversity of life forms has become enormous. In order to somehow systematize them when studying, scientists group the inhabitants of wildlife according to similar characteristics.

Living nature, non-living nature - what are the differences?

Objects of inanimate and living nature have a common quality - they have the same chemical elements. But that's where the similarities end, because only living things have the following properties:

All of them (except viruses) consist of cells.
To live, they need to receive energy from outside. Plants capture it from the sun and then use it to synthesize organic substances. Herbivores eat plants and in this way also obtain energy and everything they need to exist. And many of them themselves become food for predators.
Living organisms cannot do without metabolism with environment - they must breathe and eat, get rid of the products of their vital activity.
All living things grow and acquire new qualities, responds to changes in external conditions and reproduces organisms similar to itself (that is, it reproduces).

Living nature includes absolutely all living organisms living on Earth.

Why is nature divided into kingdoms?

Since ancient times, scientists believed that the organic world should be divided into plants and animals. The development of science has shown that such grouping does not reflect the full picture.

In the twentieth century, a new concept was introduced - the kingdom, and from this the system of recording millions of living beings became more convenient and detailed. According to modern classification, bacteria, fungi, plants and animals form separate kingdoms.

Kingdom of bacteria

Almost 10 thousand species of these microorganisms are known, but without a microscope you can’t see any of them. Bacteria are shaped like flagella, rods or balls and live everywhere- in water, air, soil and other living organisms. They can be useful and harmful. They can, for example, protect human health, turn milk into kefir, ferment cabbage, or make dough fluffy. Or they can bring illness and cause poisoning.

To date, about ten thousand species of bacteria have been described, but it is estimated that there are over a million of them.

In order to encounter less harmful bacteria in everyday life, you must follow the rules of hygiene, food processing and food preparation.

kingdom of mushrooms

And these living organisms number about one hundred thousand species. Many properties of mushrooms are unique- for example, reproduction in three ways or the presence in them of substances from which medicines and vitamins are made. But they also have characteristics characteristic of the inhabitants of other kingdoms. The presence of cell walls, immobility, and apical growth make fungi similar to plants. They are similar to animals in terms of metabolism.

plant kingdom

Plants differ from other living things in their ability to photosynthesize. This means that they convert inorganic matter into organic matter. Nature has made plants the main source of food and energy for all inhabitants of the Earth.

Representatives of this kingdom are divided into:

lower plants (various algae), in which organs such as leaves, stems and roots are not expressed;
higher (mosses, ferns, angiosperms).

Ferns vary greatly in size, life forms, life cycles, and structural features.

Further classification takes into account in more detail the characteristics of these living organisms, and there are about 350 thousand species of them on the planet.

animal kingdom

It is the most numerous - it is inhabited by almost 2 million species of animals, including humans! They are similar to plants in their need for metabolism and cellular structure. And the main differences are the consumption of ready-made organic compounds and the ability to move independently.

The classification of such a number of species is very complex, and it begins with the division of animals into unicellular and multicellular.

Is man the king of nature?

In its life cycle Man is subject to natural laws, like all other living organisms. From a biological point of view, it does not reign in nature at all, although it stands at the very top stage of evolution. That is, man is the highest developed creature on Earth. That is why he bears responsibility for the well-being of our living planet.

Why should we protect nature?

This report would be incomplete without mentioning that human activities can harm nature. People have interests everywhere - on earth and underground, in the air and water. They cut down forests and change river beds, fish and hunt, mine minerals and build cities.

There are many places that have been damaged by human activity, and nature cannot replace what has been destroyed. Many animals and plants are included in the Red Book, because they were on the verge of extinction.

Nature has both material and spiritual significance for us.

Environmental protection laws have been adopted in Russia and other countries. But also in Everyday life a person can take care of nature, for example, not litter in the forest, plant young trees or feed birds in winter.

We must remember that we have one planet, and many more generations of living beings will live on it.

The composition and distribution of the biosphere by mass is a rather interesting and significant issue in biology. Although an accurate census of all living organisms on Earth is literally impossible. It’s hard to imagine information like this: meet the bacteria Alice 43 by 10 to the 30th power, lives in a swamp near Ust-Kamenogorsk, sorry, while they were doing the census, Alice died, leaving 23 billion descendants. However, scientists were able to determine the biomass of the kingdoms of living organisms on the planet, as well as determine what influence humans had on its distribution. Although it’s too early to talk about super accuracy, the #infographics are very interesting.
results
Calculations were made in gigatons of carbon, because carbon compounds are the basis for all living things and make up about 17.5% of animals and plants, while this mass does not depend on the water content in them. 1 Gt C is equal to 10 to the 15th power of grams of carbon. According to scientists, the biomass of all kingdoms of life on the planet is 550 Gt of carbon. The lion's share of biomass is plants, about 450 Gt C, followed by bacteria 70 Gt C, fungi 12 Gt C, archaea 7 Gt C, protists 4 Gt C, animals 2 Gt C and viruses 0.2 Gt C.
Scientists also note that marine biomass, unlike terrestrial biomass, contains more consumers than producers. This refers to the food structure of the community, which is divided into consumers, producers and decomposers. Producers are organisms that create organic substances from inorganic ones, such as photosynthesis. Consumers consume the products of producers, but do not decompose them into inorganic substances, like decomposers. And decomposers are bacteria and fungi that decompose the remains of living beings to the simplest or inorganic substances. By the way, the error in counting bacteria in the results obtained is quite large.
It is also worth noting that, according to the data obtained, the underground biomass turned out to be less than aboveground, contrary to many statements of scientists. Which is understandable due to some gaps in our knowledge at the moment, especially in underground world. But the mass of leaves is 6.5 times less than the entire mass of roots. Plant biomass includes ≈70% of tree stems and trunks, which are largely metabolically inert.
The following chart shows average data for the animal kingdom. Marine arthropods have the largest carbon mass with 1 Gt C, followed by fish with 0.7 Gt C, followed by mollusks, nematodes or roundworms and terrestrial arthropods with 0.2 Gt C each. Although terrestrial arthropods are significantly more represented in terms of species than marine ones their mass is 5 times less. Marine arthropods have individual species, such as arctic krill, whose mass is only 4 times less than all terrestrial arthropods. This type of krill can be put on a par with termites, whose mass is also 0.05 Gt C, slightly less than that of humans. Next come cnidarians - these are aquatic multicellular inhabitants that have stinging cells for hunting and protection; their mass is 0.1 Gt C. The same is the mass of all livestock on the planet, which consists mainly of cattle and pigs. But people occupy only 0.06 Gt C, which is almost two times less than livestock and 11.6 times less than fish. However, humans have 8.5 times more carbon mass than all wild mammals and 30 times more than wild birds. And domestic birds, among which chickens predominate, are 2.5 times more numerous than all wild birds.
The influence of humanity on the biosphere.
Distribution of biomass across environments and nutritional regimes for individual organisms.
General food chain, trophic levels.

On our planet there are many diverse and unique creatures that are very different from each other, and therefore various organisms were assigned to different kingdoms. All living organisms, according to the type of nutrition, are divided into heterotrophs (they eat ready-made organic substances) and autotrophs (they themselves obtain organic matter from inorganic substances). The latter include plants and some types of bacteria, and the former include most bacteria, all animals and fungi. But despite some similarities, each kingdom has significant differences.

Representatives of the kingdom of bacteria

This is the most ancient group of living creatures. Bacteria can be found in all corners of the planet. They settled in the deepest depths of the oceans, in hot sulfur springs, in the crater of a volcano, in the cold ice of the Arctic, etc. All representatives of this kingdom are single-celled organisms. In terms of its structure, their cell has significant differences from the cells of other organisms. For example, the organelles of a bacterial cell include:

cell wall,
flagella,
cytoplasm,
nuclear matter.

The cell wall performs protective and supporting functions; flagella and villi serve as organs of movement. The cytoplasm has a very thick texture that contains nutrients. In the center of this cell there is an accumulation of nuclear substance, which contains hereditary information. These organisms are classified as prokaryotes because they do not have a nucleus. Under unfavorable conditions, bacteria form a spore in which they can remain for a very long time.

Representatives of the animal kingdom

Creatures that belong to this kingdom can have both a unicellular and multicellular structure. But the cell of any represented organism has its own distinctive features from cells of other kingdoms. It does not have a dense cell wall. It has no vacuoles. Glycogen accumulates as a reserve nutrient substance. And an animal cell has a cellular center.

kingdom of mushrooms

These organisms have characteristics of animals and plants. Their cell wall contains chitin, which stores glycogen. Some fungi may contain several nuclei in their cells. These organisms, like plants, are immobile.

The living world of our planet is very diverse. Created for his research the whole system science is biology, and plants, bacteria, fungi, lichens and other species are the subject of its study. Modern science The following types are already known, described and classified:

animals - over a million;
plants - about half a million;
mushrooms - several hundred thousand;
bacteria – more than ten thousand.

But at the same time, the number of species that have not yet been described is approximately the same (and in the case of microorganisms, even more).

In biology, there are several classifications of organisms according to various characteristics. Let us dwell on two of them, which will be used further. brief description plants, bacteria, fungi and lichens.

In biology, two groups are distinguished in terms of the relationship of cells to oxygen:

Aerobes. For their life to function, free access to molecular oxygen is necessary. In its absence, they die.
Anaerobes. They live in environments without access to oxygen, which is harmful to them.

In addition, there are facultative anaerobes, capable of switching from one type of respiration to another, and aerotolerant anaerobes, indifferent to the presence or absence of oxygen.

The given classifications are conditional, since sometimes it is quite difficult to classify an organism into one group or another.

Plants

One of the main groups of multicellular organisms are plants. Biology includes trees, shrubs, flowers, grasses, mosses, ferns, horsetails, mosses, etc. Often algae are classified as plants - all or only certain species.

Plant properties

TO characteristic features Plants in biology are usually classified as follows:

cells have a dense (usually cellulose) shell that does not allow solid particles to pass through;
the overwhelming majority are phototrophs capable of photosynthesis, which results in the release of free oxygen;
most often have a green color due to the pigment contained in the cells (chlorophyll);
lead a predominantly sedentary lifestyle;
growth occurs throughout life;
most often there is a division into underground and above-ground parts.

It cannot be said that all the signs are unique, but nevertheless, they make it possible to understand which group of organisms we are talking about.

About half a million plant species have been described in biology. This number is increasing all the time, as new species are constantly being discovered.

Cultivated plants

Plants, like animals, have been domesticated by humans. In addition, new varieties and new types of plants were developed.

The most important of them are the following:

cereals - wheat, rye, barley, oats, millet, sorghum;
pulses – beans, peas, lentils;
sugar - sugar beets and sugar cane;
oilseeds – sunflower, peanuts, olives.

Do not forget about grains, vegetables, fruits, berries and other cultivated plants. This also includes tea, coffee, cocoa, grapes, flowers, tobacco, fodder and industrial varieties of plants.

Meaning

The importance of plants is difficult to overestimate. First of all, this is the enrichment of the atmosphere with oxygen. Plants are active participants in the cycle of substances in nature; they serve as part, and sometimes the basis, of nutrition for many organisms, including humans. The steppes, meadows and forests inhabited by them are the habitat of other representatives of flora and fauna. Plants participate in the formation of soil and protect it from erosion.

Plants are widely used by humans in the following industries:

food industry – berries, fruits, vegetables, edible plants;
light industry - production of fabrics from fibrous plants: cotton, flax, hemp;
woodworking and construction - production of cellulose, production and use of building materials, wooden utensils, matches, furniture;
energy – the use of wood and its derivatives (briquettes from wood shavings and dust, coal, peat) as a source of energy;
chemistry and medicine - rubber, valuable resins, essential oils, dyes, medicinal plants and vitamins.
livestock farming - various grasses as fodder.

Bacteria

Bacteria are single-celled microorganisms ranging in size from 0.5 to 13 microns (0.0005-0.013 mm). Some of them lead a sedentary lifestyle, while others can move by wriggling, sliding along the surface, or with the help of flagella located at one or both poles of the cell.

In biology, it is customary to distinguish the following types according to the shape of bacteria:

spherical - cocci and their groups in the form of two cells (diplococci), chains (streptococci), clusters (staphylococci) and other variants;
rod-shaped, including bacilli (dysentery, plague bacilli);
curved - vibrios, spirilla, spirochetes.

Habitat

Bacteria live almost everywhere - in air, water, soil, in dead and living tissues of plants, animals and humans. Their life activity is influenced by the main factors:

Temperature. The optimal range is considered to be from +4 to +40°C.
Oxygen. Among the bacteria there are aerobes, anaerobes, facultative anaerobes, and even aerotolerant anaerobes, such as lactic acid bacteria.
Acidity. For most bacteria, an acidic environment is harmful.
Direct sunlight. Most bacteria die when exposed to direct sunlight.

Unfavorable conditions lead to a slowdown or complete stop of the reproduction of bacteria, and can also cause their death. Some bacteria, for example, bacilli that cause tuberculosis and anthrax, are capable of forming spores. This process is well studied by biology and consists in the transition of the cell to a state of rest and the formation of a dense protective shell around it. The spore can tolerate exposure to harmful external factors for quite a long time - up to tens and sometimes hundreds of years, without losing viability. In conditions suitable for life, the spore germinates, and from it emerges living cell bacteria.

Properties

Bacteria reproduce by simply dividing the cell into two parts. Under favorable conditions, their number can double every 15-20 minutes. In addition, a primitive form of sexual reproduction has been recorded in biology.

IN natural conditions bacteria perform the following roles:

supply plants with many useful substances, such as nitrogen;
decompose manure, fertilizers, dead remains of plants and animals;
participate in the processing of fiber, located in the esophagus of animals and humans.

Bacteria are used by humans for the following purposes:

production of vinegar and vitamin C – acetic acid bacteria;
production of fermented milk products, cheeses, pickling of vegetables, production of silage - lactic acid bacteria;
production of antibiotics – streptomycetes.

At the same time, bacteria cause spoilage of products, lead to various diseases of plants and animals, and serve as a source of human diseases such as diphtheria, tonsillitis, dysentery, tuberculosis, plague, cholera and others.

Mushrooms

Modern biology knows about one hundred thousand species of fungi. Their uniqueness lies in the combination of the properties of plants and animals.

Fungi share the following properties with plants:

the presence of a cell membrane;
immobility and growth throughout life;
reproduction by spores;
feeding on organic matter dissolved in water.

Like animals, mushrooms have the following characteristics:

belong to pronounced heterotrophs;
not capable of photosynthesis;
the reserve nutrient is glycogen, not starch;
The cell wall is chitinous, not cellulose.

Properties

The body of the fungus is formed by thin threads (hyphae). Their totality in biology is called mycelium, or mycelium. The growth of the fungus is accompanied by the penetration of hyphae into the nutrient medium, where they grow, forming multiple branches.

In biology, there are several classifications of fungi:

In nature, fungi, by promoting the decomposition of various organic materials, increase soil fertility. Mushrooms are used by humans in the following areas:

food industry – edible mushrooms for cooking, microscopic mushrooms and yeast for preparing drinks by fermentation and fermentation of food products;
medicine – production of antibiotics and other medicinal drugs;
chemistry - production chemical substances for technical purposes.

At the same time, mushrooms can cause skin diseases and diseases of internal organs in humans. Poisonous mushrooms and foods contaminated with toxins from microscopic fungi lead to serious poisoning, sometimes fatal. Hallucinogenic mushrooms are also harmful. In addition, negative phenomena include plant diseases caused by fungi, destruction of the wood of living trees, and spoilage of products by mold fungi.

Lichens

Biology considers lichens as a community of fungi (90% of the composition) and unicellular algae (10%), and sometimes cyanobacteria. Heterotrophic fungi supply algae with water and minerals absorbed from the soil. Autotrophic algae provide fungi with the organic substances they synthesize.

Properties

The body of the lichen (thallus) can be homomeric, when algae are randomly located between the hyphae of fungi, and heteromeric, that is, have ordered functional layers.

Reproduction of lichens is carried out through algal cells entwined with fungal hyphae, which are formed inside the thallus (soredia) or look like outgrowths on the body of the thallus (isidia). In addition, a piece of dried thallus carried by the wind to a favorable environment can form a new lichen.

This unique structure of lichens allows them to survive in conditions that are unsuitable for the separate existence of fungi and algae. Biology has actually established the ability of lichens to survive for a long time without moisture, to survive at temperatures of –50 and +60°C. Their photosynthesis continues even at subzero temperatures. Moreover, most lichens die even with slight environmental pollution.

Meaning

Lichens, being the first to colonize lifeless areas, prepare the environment for other organisms. They serve as food for animals, such as reindeer, and some species are edible even for humans. Used to produce paints and litmus. Serve as biological indicators of environmental pollution.

Moreover, lichens are the cause of the first stage of rock erosion.

Biology provides answers to the question of the benefits or harm of this or that representative of living nature. But it is a generally accepted fact that there are no “unnecessary” organisms. Removing any member from any ecosystem has a negative impact on the entire environment.

The role of an individual organism cannot be judged abstractly, because in nature there are widely developed relationships between various types. Thus, plants often live in symbiosis with fungi, supplying each other with the necessary substances. The lichens discussed above are also an example of mutually beneficial cooperation.