Interesting biology. Why are fungi and bacteria called decomposers? Who reigns in living nature All living organisms animals plants fungi bacteria

Traditionally, all living organisms are divided into three domains (superkingdoms) and six kingdoms, but some sources may indicate a different classification system.

Organisms are placed into kingdoms based on similarity or general characteristics. Some of the traits that are used to define a kingdom include: cell type, nutrient acquisition, and reproduction. The two main types of cells are and cells.

Common methods of obtaining nutrients include absorption and ingestion. Types of reproduction include and.

Below is a list of the six kingdoms of life and a brief description of organisms contained in them

Kingdom of Archaea

Archaea growing in the "morning glory" lake in national park Yellowstone, produce vibrant color

Initially, these prokaryotes with one were considered bacteria. They are found in and have a unique type of ribosomal RNA. The composition of these organisms allows them to live in very challenging environments, including hot springs and hydrothermal vents.

• Domain: Archaea;
• Organisms: methanogens, halophiles, thermophiles, psychrophiles;
• Cell type: prokaryotic;
• Metabolism: depending on the type - metabolism may require oxygen, hydrogen, carbon dioxide, sulfur, sulfide;
• Method of nutrition: depending on the species - food consumption can be carried out by absorption, non-photosynthetic photophosphorylation or chemosynthesis;
• Reproduction: Asexual reproduction by binary fission, budding or fragmentation.

Note: in some cases, archaea are classified as a member of the Kingdom of Bacteria, but most scientists classify them as a separate Kingdom. In fact, DNA and RNA data show that archaea and bacteria are so different that they cannot be combined into one Kingdom.

Kingdom Bacteria

Escherichia coli

These organisms are considered true bacteria and are classified under the domain of bacteria. Although most bacteria do not cause illness, some can cause serious illness. Under optimal conditions, they reproduce at an alarming rate. Most bacteria reproduce by binary fission.

• Domain: ;
• Organisms: bacteria, cyanobacteria (blue-green algae), actinobacteria;
• Cell type: prokaryotic;
• Metabolism: depending on the species - oxygen may be toxic, transportable or necessary for metabolism;
• Method of nutrition: depending on the type - food consumption can be carried out by absorption, photosynthesis or chemosynthesis;
• Reproduction: asexual.

Kingdom Protista

• Domain: Eukaryotes;
• Organisms: amoebas, green algae, brown algae, diatoms, euglena, slimy forms;
• Cell type: eukaryotic;
• Feeding mode: depending on the species - food consumption includes absorption, photosynthesis or ingestion;
• Reproduction: predominantly asexual. occurs in some species.

Kingdom Mushrooms

Includes both single-celled (yeast and mold) and multicellular (fungi) organisms. They are decomposers and obtain nutrients through absorption.

• Domain: Eukaryotes;
• Organisms: fungi, yeast, mold;
• Cell type: eukaryotic;
• Metabolism: Oxygen is necessary for metabolism;
• Nutrition method: absorption;
• Reproduction: sexual or asexual.

Plant Kingdom

They are extremely important for all life on Earth, as they produce oxygen and provide other living organisms with shelter, food, etc. This diverse group contains vascular or avascular plants, flowering or non-flowering plants, and others.

• Domain: Eukaryotes;
• Organisms: mosses, angiosperms (flowering plants), gymnosperms, liverworts, ferns;
• Cell type: eukaryotic;
• Metabolism: Oxygen is necessary for metabolism;
• Nutrition method: photosynthesis;
• Reproduction: Organisms undergo alternating generations. The sexual phase (gametophyte) is replaced by the asexual phase (sporophyte).

Animal Kingdom

This Kingdom includes everyone. These multicellular eukaryotes depend on plants and other organisms for sustenance. Most animals live in aquatic environments and range from tiny tardigrades to extremely large blue whales.

• Domain: Eukaryotes;
• Organisms: mammals, amphibians, sponges, insects, worms;
• Cell type: eukaryotic;
• Metabolism: Oxygen is necessary for metabolism;
• Method of feeding: ingestion;
• Reproduction: Most animals reproduce sexually, but some animals reproduce asexually.

Some animals eat plants. Others are the flesh of organisms that consume plant foods. And those, in turn, can be eaten by humans. But every living thing ever has a time, that’s how nature works.

Law of Nature Renewal

In fact, imagine if organisms existed forever? The world would have long ago experienced overpopulation, leading to a lack of stable nutrition, as well as global pollution environment. Therefore, according to the laws existing in the biosphere, all living organisms are born, grow up, leave offspring, grow old and die. And the biosphere is thus updated every second!

Kingdoms of nature: plants, animals, fungi, bacteria

All of them are involved in this reasonable and balanced And when any organism ceases its vital activity, the hour of decomposition of matter into its components begins. And here bacteria and fungi come to the aid of nature itself. Why are fungi and bacteria called decomposers? This concept can be directly related to their activities.

Saprophytes

This is the scientific name for those organisms that obtain their nutrition from the remains of other animals and plants. These mainly include bacteria and fungi. They decompose dead flesh into “raw materials” - inorganic simple compounds, microelements, allowing nature to build new organisms from them or use them to feed existing ones. This is why fungi and bacteria are called decomposers. But with their destructive activity they bring more benefit than harm.

A world without saprophytes

Imagine what would happen if bacteria and fungi did not process dead cells? Life itself would probably have suffocated under the hourly increasing layer of dead remains. And saprophytes, by providing nutrition, “recycle” dead tissue, and act as orderlies or janitors, helping to remove unnecessary things and recycle waste. That is why fungi and bacteria are called decomposers, utilizing the remains of dead organisms. The positive effect of this global influence has now been scientifically proven. biological process on the environment.

Entertaining biology: bacteria, fungi, plants - saprophytes

The concept itself has Greek roots and comes from two words “rotten” and “plant”. What organisms can be attributed to this group?

• First of all, these are many bacteria. They decompose organic matter, cause rotting of food, and participate in mineralization and nitrogen fixation. And some bacteria even break down cellulose and form hydrocarbons. Some microorganisms are particularly demanding of the substrate: they use only certain types organics (for example, dairy products). Others are practically omnivorous and can eat a variety of organic compounds: alcohols, proteins, carbohydrates and acids.
• Many large mushrooms can also be included in this group. After all, straw and humus, fallen leaves, manure, feathers, fallen antlers and much more serve them as a substrate with nutrients. As a rule, it lives on the remains of foliage and trees, and conifers are chosen. The white dung beetle develops in nitrogen-rich places. And they spoil human food, making it unusable. Many fungi enter into symbiosis with higher plants, processing their waste into microelements that plants can feed from the soil. This process is mutually beneficial and is sometimes reflected in the names of the mushrooms themselves: boletus, boletus. A group of predatory fungi that feed on small insects can also be conditionally classified as saprophytes. Because when there is no live prey, they can feed on dead organic matter.
• There are saprophytes among fauna representatives. These include: sundew, mistletoe, dodder, for example.

Now you know why fungi and bacteria are called decomposers (rather, they mean their positive role in nature). All saprophytes and saprophages are “responsible” for the circulation of substances in the biosphere and the disposal of dead organisms, without which, probably, the planet would cease to exist.

ANIMAL KINGDOM.

The main difference between an animal organism and a plant organism is that in animal cells there are no chloroplasts and no chlorophyll.
However, most animal and plant organisms have similar, i.e. identical life processes. For example, the breathing process. Almost all living organisms breathe oxygen while releasing carbon dioxide. The exception is some organisms, including a large group of anaerobic bacteria.
This releases the energy necessary for the existence of the organism. Actually, all living things are characterized by the process of metabolism. The body receives some things and throws others out.
the body in the process of respiration (carbon dioxide, water vapor, etc. are released), digestion (feces), sweat, urine. These are waste substances that are no longer needed by the body. In other words, metabolism occurs.

Metabolism is the main property of all life on Earth.
Oxygen, oxygen gives life to organisms -
In each cell, oxidation occurs in our
It’s like there’s a fire in a stove—the substances are boiling and bubbling.
And energy is released from us,
That’s why we walk, write and read, and hear everything.
After all, metabolism, of course, is the main property for us,
That’s why we live and breathe every moment and every hour.

MICROORGANISMS. Varieties, Ecological significance.
Microorganisms include very small organisms that can only be seen and examined under a microscope:
1.Eukaryotes are higher microorganisms (algae, fungi, protozoa). Their cells have a differentiated nucleus with a set of chromosomes, delimited from the cytoplasm by a nuclear membrane. The cytoplasm contains a developed endoplasmic reticulum, as well as mitochondria and ribosomes.
2. Prokaryotes - lower microorganisms (blue-green unicellular algae and bacteria). They do not have a differentiated nucleus; the DNA lies freely, immersed in the cytoplasm.
3. Viruses. Translated into Russian, the word virus means “poison”. Virus classification is based on type nucleic acid(DNA - viruses and RNA - viruses), the presence or absence of outer shells, as well as the number of capsomeres in the capsid and the type of their folding (type of symmetry). Among them are a huge number of viruses that cause diseases in plants (tobacco mosaic disease), animals (mammal pox) and humans. The latter include adenoviruses (febrile diseases with symptoms of respiratory tract damage..), herpesviruses (herpes, chickenpox...), poxviruses (natural blackpox), myxoviruses (influenza, mumps, rubella).
BLUE-GREEN unicellular algae (a group of prokaryotic cyanobacteria)
live mainly in water and have great importance, since they saturate water with oxygen during the process of photosynthesis.
BACTERIA.
The average cell diameter is 1 micron, length varies from 0.1 to 10 microns. Bacteria have mastered a wide variety of habitats: they live in water, soil, dust, in the air, on the outer covers of plants and animals, including humans, as well as inside these organisms, often causing diseases. All bacteria are divided into 19 groups, which are of great importance for humans. There are bacteria that live with it and help it. Such symbionts include, for example, E. coli. She is the “mistress” of the large intestine (only the large intestine, no more). But among bacteria there are also those that cause diseases in both animals and humans (for example, anthrax...). Among the bacteria that cause diseases in humans are: spirochetes (syphilis), staphylococci, streptococci (pneumonia, sepsis), gonococci (gonorrhea), salmonella (typhoid fever, paratyphoid fever), shigella (dysentery), mycobacteria (tuberculosis), rickettsia ( typhus), chlamydia (trachoma) and others.
According to morphology ( external structure) bacteria are divided into three main groups:
rod-shaped (actually bacteria and bacilli);
spherical (staphylococci, streptococci, micrococci, diplococci, gonococci,
Tetracoccus, Sarcinus);
convoluted (vibrios, spirilla, spirochetes, leptospira).

Bacteria also play an important role in soil fertility.
They and other microorganisms, together with fungi, decompose and mineralize dead plant and animal remains, turning them into substances available for plant nutrition (humus). Without soil bacteria and fungi (true decomposers), annually falling leaves, pine needles, and animal remains would accumulate in huge quantities and prevent forest regeneration. This also applies to bodies of water.
This is the ecological significance of soil bacteria and other microorganisms. Their main function is to cleanse our common home.

The kingdoms of fungi and bacteria are the most ancient on Earth. These organisms are relatively simple in structure. The groups are multifaceted and include a wide variety of representatives. There are many similarities between fungi and bacteria, but there are such obvious differences that scientists have classified these organisms into different kingdoms.

Fungi belong to one of the numerous and thriving groups of lower organisms that are found in all geographical zones. Up to hundreds of thousands of species of fungi live in nature: from the smallest single-celled ones (yeast) to very large ones (tinder fungi). They have adapted to a variety of living conditions: in forests, fields, soil, water, on the walls of homes, as well as in the bodies of other animals and plants, both living and dead. To exist, mushrooms require certain conditions: moisture and warmth (20-25 degrees). The age of the most ancient fossil fungal spores is 170-190 million years.

Mushrooms reproduce in three ways:

a) vegetative (pieces of mycelium);

b) asexual (through spores);

c) sexual (male and female gametes).

In the kingdom of fungi, there are lower ones, in which the body is represented by a single cell, and higher ones, which have a multicellular mycelium.

Mushrooms are also divided by food type into:

b) moldy;

c) hats.

The most ancient organisms on the planet, living for more than 2 billion years, are bacteria, numbering about 2,500 species. They can be found everywhere in everyday life, as well as at a depth of up to 7 km in the earth and ocean, at an altitude of up to 40 km, at a temperature of about 90 degrees. All bacteria are microscopic in size. They have a cellular structure, consisting of one or several cells in the form of clusters or chains. The largest bacterium is Epulopiscium, measuring up to 0.5 mm. Bacterial cells do not have a nucleus; they reproduce asexually - simple division with genome doubling. Based on the method of respiration, bacteria are divided into aerobic ( organic matter oxidize with the participation of oxygen and release carbon dioxide, chemical energy and water) and anaerobic (instead of respiration, a fermentation process occurs without the participation of oxygen with the release of energy). Aerobic bacteria live on the surface of the soil cover, in the atmosphere and in the upper layers of water; anaerobic bacteria live without oxygen.
Most bacteria do not contain chlorophyll; they feed heterotrophically, using organic and inorganic substances and sunlight for energy. There are also autotrophic bacteria that can live exclusively in an inorganic environment.

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 substances. 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.

Foliose 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 in places inaccessible to other organisms through the process of photosynthesis. 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