The living world of our planet is very diverse. For its study, a whole system of sciences has been created - biology, and plants, bacteria, fungi, lichens and other species are the subject of its study. Modern science already knows, describes and classifies the following types:
- 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 in a further brief description of 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
The characteristic characteristics of plants in biology are usually considered to include the following:
- 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 withstand the effects of harmful external factors for quite a long time - up to tens and sometimes hundreds of years, without losing its viability. In conditions suitable for life, the spore germinates and a living bacterial cell emerges from it.
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.
Under 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 of chemicals 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 different species. 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.
The main characteristics of living things: SELF-RENEWALING, SELF-REPRODUCTION and SELF-REGULATION.
They define and basic properties of living things:
1) MATERIALITY;
2) STRUCTURED - living organisms have a complex structure;
3) METABOLISM - living organisms receive energy from the environment and use it to maintain their high orderliness;
4) MOVEMENT;
5) HEREDITARY and VARIABILITY - living organisms not only change, but also become more complex; and are also able to transmit to their descendants the information embedded in them, necessary for life, development and reproduction;
6) REPRODUCTION - all living things reproduce;
7) IRRITABILITY - the ability to respond to external irritations;
8) ONTO- and PHYLOGENESIS;
9) DISCRETE;
10) INTEGRITY.
Generalizing and somewhat simplifying what has been said about the specifics of living things, we can say that all living organisms eat, breathe, grow, reproduce and spread in nature, while inanimate bodies do not feed, do not breathe, do not grow and do not reproduce.
Kingdom of Viruses.
Their peculiarities : small size; lack of cellular structure; simple chemical composition; the impossibility of existing outside the host's body.
Form viruses: rod-shaped, filiform, spherical, cuboid, club-shaped.
Mature virus particles - virions- consist of two main components: DNA or RNA and protein.
Viruses are the causative agents of many plant and animal diseases. In past centuries, viral infections were epidemic in nature, covering vast territories.
For example, in Europe, 10-12 million people fell ill with smallpox and 1.5 million people died. Of particular note is measles. Today, more than 2 million children die from measles every year.
Viral diseases cause enormous damage to agriculture. The foot and mouth disease virus is very dangerous for animals. Appearance , the most probable hypothesis seems to be one that interprets viruses as a result of the degradation of cellular organisms. There is another opinion that viruses can be considered as groups of genes that have escaped the control of the cell genome.
Kingdom Bacteria .
Age The most ancient bacteria are at least 3-3.5 billion years old. Many bacteria, according to scientists, appeared relatively recently. They emerge from the ice of the Arctic and Antarctica, penetrate oil wells, live in the water of hot springs, the temperature of which reaches 92°C, abundantly inhabit all types of soils and water bodies, and rise with air currents to a height of 85 km.
Bacteria in Greek means rod. Bacteria were discovered by the Dutchman A. Leeuwenhoek in 1675, but only Louis Pasteur for the first time showed the role of bacteria in the process of fermentation and other transformations of substances in nature. There are 5,000 species of bacteria.
FEATURES OF THEIR STRUCTURE:
§ small dimensions (0.0001 mm);
§ a typical prokaryotic cell, there is no separate nucleus, mitochondria, plastids, Golgi complex, nucleolus, chromosomes, etc.;
§ special structure and composition of membrane structures and cell walls;
§ The shape of the cells can be spherical, rod-shaped and convoluted.
Among bacteria, according to the source of energy used, they are distinguished PHOTOTROPHES and CHEMOTROPHS.
Photosynthetic bacteria use light energy to synthesize organic substances. Chemosynthetic bacteria use energy released during the oxidation of any inorganic substances in the environment to synthesize organic substances.
AUTOTROPHIC - capable of synthesizing organic substances of their body from inorganic compounds.
HETEROTROPHIC - unable to synthesize organic substances from inorganic ones, therefore they require the supply of ready-made organic substances from the outside in the form of food.
SAPROPHYTES are bacteria that settle on dead, remains of plants and animals.
Kingdom of Mushrooms.
The kingdom of Mushrooms has 100,000 species, diverse in structure and lifestyle. Mushrooms is a separate group of cellular nuclear heterotrophic organisms that are similar to both animals and plants.
Signs of similarity between mushrooms and animals: the nature of metabolism associated with the formation of urea; heterotrophic type of nutrition; the content of chitin in the cell wall; the formation of a reserve product - glycogen.
Signs of similarity between mushrooms and plants: nutrition by absorption; unlimited growth; presence of a cell wall in cells; reproduction with spores.
STRUCTURE OF MUSHROOMS
The body of the mushroom consists of special intertwining threads - hyphae (mycelium). The cap mushroom consists of a mycelium and a fruiting body. And the fruit part is made from a cap and a stump.
A characteristic feature of fungi is their heterotrophy : some fungi settle on the dead remains of plants and animals; some feed on living things; some enter into symbiosis with plants.
Reproduce fungi asexually and sexually. Asexual reproduction is carried out vegetatively and by spores. The forms of sexual reproduction in fungi are varied and are divided into three groups: gametogamy, gametangiogamy, and somatogamy.
ROLE OF MUSHROOMS. Fungi are the main group of decomposers in ecosystems. They participate in soil formation, act as orderlies, and serve as food and medicine for animals.
On our planet there are many diverse and unique creatures that are very different from each other, and therefore different organisms have been 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.
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 contain 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 exchanging substances with the 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 even in everyday life, a person can take care of nature, for example, not littering in the forest, planting young trees or feeding 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 into simple 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 the underworld. 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.
