The largest number of species is characteristic of the ecosystem. Ecological system: concept, essence, types and levels

The interrogation of a suspect in the investigation of burglaries is one of the most difficult investigative actions, which is explained by the criminal procedural specifics of the position of the suspect.

A suspect is a subject in respect of whom there is sufficient evidence to detain him under Part 1 of Art.

1 st. 91 of the Criminal Procedure Code of the Russian Federation, or for the application of a preventive measure in accordance with Art. 100 of the Code of Criminal Procedure of the Russian Federation, but not allowing him to be charged.

A person detained on suspicion of committing a crime is held in custody for 48 hours (Article 94 of the Code of Criminal Procedure of the Russian Federation) or 1 day, if a measure of restraint is applied to him until charges are brought in accordance with Art. 100 Code of Criminal Procedure of the Russian Federation 1 . If suspicions are confirmed after 10 days, then the suspect acquires the status of the accused, otherwise the measure of restraint is canceled, and the suspect is released.

If there are grounds provided for by the criminal procedural legislation, detention, as a rule, is carried out immediately if a person is caught directly at the time of the theft, or the implementation of any actions directly aimed at its preparation, implementation or concealment of traces, and also if eyewitnesses directly point to him as having committed a crime. In addition, the basis for the detention of a suspect may be traces found on his clothes, body, with him or during a search, in his home, directly indicating the commission of a crime.

If there are several suspects in the case, then it is advisable to detain them simultaneously and in such a way as to exclude the possibility of their premature knowledge of the upcoming arrest, as well as to eliminate the likelihood of their communication, both at the time of detention and after it.

The detention should be unexpected for the criminals and carried out exactly when they least expect it and have not yet taken measures to conceal or destroy the traces of the crime.

It is most expedient to interrogate a suspect immediately after his detention or arrest, which justifies itself from a tactical point of view, although in some cases the interrogation is carried out no later than 24 hours from the moment of detention or the application of a measure of restraint in accordance with Part 2 of Art. 46 Code of Criminal Procedure of the Russian Federation. The first interrogation of a suspect is complicated by the fact that the investigator has at his disposal a rather meager information base regarding the subject of the interrogation and the personality of the interrogated, with the impossibility of replenishing it in the conditions of an extreme shortage of time necessary to prepare for an effective interrogation. Such a negative element of the tactics of interrogating a suspect must be overcome by the professionalism of the investigator, his ability to apply multivariate interrogation tactics and use all the advantages that will contribute to a favorable outcome of the investigative action. In this regard, on the side of the investigator, the facts of the immediacy of the interrogation of a person after his arrest, which causes the interrogated person to feel depressed and doomed, as a result of which the suspect, not being able to think through in detail and clearly the line of his behavior, sets out false testimony during interrogation with obvious internal contradictions. In the case of the arrest of a person "in hot pursuit", the suspect, being in a state of strong mental arousal, as a rule, is inclined to give truthful testimony. False testimony presented in this case is often not well thought out and is easily refuted through the production of confrontations and repeated interrogations.

The suspect, due to the specifics of his procedural position, is not interested in establishing the truth in the case, and therefore is prone to distorting or withholding reliable information on the case, while having, in comparison with other participants in the process, the most complete amount of knowledge about the forensic event.

Giving evidence by a suspect is his right, not an obligation, and therefore he does not bear criminal liability for refusing to give and for giving knowingly false testimony, in which he finds the realization of his “right to defense 2 .

The investigator, in turn, anticipating reticence and omissions on the part of the suspect, must always seek truthful testimony from him 1 .

For these purposes, the investigator, when planning the tactics of interrogating a suspect, proceeds from the volume of the evidence base and the position of the interrogated in relation to the existing suspicion. It is the position of the suspect, his line of conduct during interrogation in relation to the criminal event of interest to the investigation, that is one of the classifying signs of the investigative action in question.

A thorough analysis of the forensic literature shows that forensic scientists identify various situations that develop during the preparation and production of the interrogation of a suspect, which is based on the above-mentioned classifying feature.

According to V.A. Obraztsov and A.A. Toporkov, it is necessary to single out a simple, complex and super-complex situation that arises during the interrogation of a suspect.

From the point of view of O.Ya. Baeva, interrogation tactics are built in the demon conflict situation; in a conflict situation “without strict rivalry”; in a conflict situation "with strict rivalry".

It seems to us more appropriate to consider the tactics of interrogating a suspect in a conflict and non-conflict situation, the need for which E.E. Centerov, A.G. Filippov, A.A. Schmidt.

A conflict-free situation is characterized by the fact that the interrogated person, having full information about the criminal event, intends to inform the investigator and admit his participation in the crime. Interrogation tactics in such a situation are aimed at obtaining sufficiently detailed testimony about all the circumstances of the crime committed, which in itself is more important than obtaining an interrogated confession of guilt, which may contain false details. In this regard, a conflict-free situation is fraught with the risk of self-incrimination by the suspect, the presence of which the investigator is guided by the schematic and memorized testimony; the use by the interrogated of expressions and phrases unusual for him, due to his age and education; inability to state facts that should be known to the suspect as a person who committed the crime."

Tactical methods of interrogating a suspect, aimed at exposing him in self-incrimination, do not differ from methods that expose other false testimonies, the specifics of which we will describe in the course of covering the working stage of interrogation.

A conflict situation arises when the suspect categorically refuses to tell everything that he knows about the case and denies his involvement in the crime. The conflict of such a situation is aggravated by the fact that limited initial information acts as an information base for interrogation, which is not sufficient for incriminating evidence. Therefore, in such a situation, "the first interrogation of a suspect is to a certain extent exploratory in nature and is aimed at clarifying the personal characteristics of the interrogated person, his position, arguments and obtaining the information that he intends to communicate" .

Tactical methods of interrogating a suspect in a conflict situation include: identifying and establishing motives for giving false testimony; presentation of evidence

Telstv; stimulation of the positive qualities of the interrogated; establishing psychological contact, etc., which we will discuss in more detail when describing the algorithm of the investigator's actions in relation to all stages of interrogation.

Procedural position, F.I.O. interrogated
Place of interrogation:
Interrogation start and end times:
Technical means of fixation:
Participants in the investigative action: No. p / p Circumstances to be clarified Evidence available in the case Questions to the interrogated Tactical methods Circumstances are presented by episodes in the chronological order of their clarification - they are presented to you briefly, with reference to the sheets of the case Questions are formulated in the sequence of their statement Tactical techniques are given with a focus on the behavior of the investigator and the interrogated and predicting possible situations
Psychological contact is a state of communication in which the participants in the interrogation feel the need for joint activities, for the transfer and exchange of information.
The interrogated person's free story is a presentation of the facts known to him in the sequence that seems to him the most acceptable or recommended by the investigator.

EXAMPLE LIST OF QUESTIONS FOR EXAMINATION OF A WITNESS
In connection with what circumstances did the witness appear at the scene of the incident and what did he do there?
Where, when and what happened at the scene?
What preceded the wrongful act?
Who, where exactly was at this time at the scene?
Who, what actions and against whom was committed at the crime scene?
How did the criminals get to the scene and how did they leave it?
How many criminals, victims were at the scene, what did they look like (signs of appearance)?
How did the criminals communicate with each other before the commission of the crime, at the time of the illegal act and after it?
Did the perpetrators communicate with the victim? If they did, what was the nature of that communication?
Does the witness know the victims, suspects and what kind of relationship does he have with them?
Did the criminals have a weapon, by whom and when it was used, under what circumstances, its individual characteristics?
Did the criminals have vehicles (if they did, what exactly, their brand, state number, individual signs, where they were located)?
What protective actions did the victims and those with them perform during and after the commission of the crime?

What bodily injuries (traces-layers) could remain on the victims, criminals? What damage could remain on the clothes of victims, criminals?
Has anyone taken action to stop the crime? What is the nature of these actions and their consequences?
What did the witness himself do to stop the crime, did he pursue the offender?
What kind weather(illumination, audibility) were at the time of the crime?
At what distance was the criminal event perceived?
Does the witness have visual or hearing impairments?
Will he be able to identify criminals, weapons, objects of criminal encroachment and by what signs?
EXAMPLE LIST OF QUESTIONS FOR INTERROGATION OF A VICTIM
Where, when and under what circumstances was the crime committed?
What bodily injuries (their nature, localization, etc.) did the victim receive?
When and to which medical institution did you seek help?
Who specifically provided medical assistance (the nature of this assistance)?
When and why was the victim at the scene?
What circumstances (victim behavior, etc.) preceded the commission of the unlawful act?
How did the criminals arrive at the scene, how did they leave it?
Who else could observe the events (from what distance) taking place at the scene?
How many attackers were at the scene, what are their signs?
What specific actions (threats) and in what sequence were committed by each of the criminals?
What weapons (objects of attack) did the criminals have, appearance and signs? Who and under what circumstances used weapons?
Did the criminals have vehicles (if they did, which ones: brand, state number, individual characteristics, parking place, etc.)?
What is the nature of the protective actions of the victim and persons from his environment?
What traces, instruments of the crime could have been left at the scene?
What traces on the body of criminals, their clothes may indicate the commission of an unlawful act and stay at the scene?
What is the value, name, individual signs of stolen valuables, damaged items and things?
Who could know about the presence of certain valuables, jewelry, etc. in the victim?
To whom did he first report what had happened and what actions did he take to prosecute the criminals?
Who (and in connection with what circumstances) is suspected of committing a crime?

Can it identify criminals, stolen property, motor vehicles and on what grounds?
What is his physical and mental condition? Did you drink alcohol the day before (what kind, how much) or drugs?
What are the reasons for the late appeal to the internal affairs bodies?
EXAMPLE LIST OF QUESTIONS FOR INTERROGATION
SUSPECT
When, with whom, in connection with what circumstances did he appear on the scene?
When, where, on whose initiative and under what circumstances were criminal acts committed in a particular episode?
Who can confirm his testimony about the circumstances set forth?
How many people were at the scene of the incident (their identification data, information about external signs, signs of clothing, shoes), what actions did they perform?
What is the sequence and what is the nature of the violent actions and threats by the suspects against each of the victims?
How did you arrive at the scene and leave it?
What weapon and what items were used in the commission of the crime, the circumstances of its use, individual characteristics, places of acquisition, manufacture, storage before the crime and subsequent concealment?
How did the interrogated communicate with each other before committing, during the commission of criminal acts and after them?
What kind vehicles were used before and after the commission of the crime (brand, state number, individual signs, parking places, etc.)?
How did the victim behave before and at the time of the crime, what actions were committed by the persons who were with him?
What injuries and under what circumstances were caused to the suspect and the victim at the time of the crime?
What and in what quantities was stolen, signs and signs of the stolen?
Where did the suspect hide or through whom, under what conditions did he sell the stolen property?
Did the suspect know the victim before, did he have information about the presence of his property?
Who initiated the crime and why?
What preparations were made to commit the crime?
Has he committed any illegal acts before, if so, which ones, where, when, with whom and in relation to whom?
Have you been prosecuted before, if so, when, where and for what; type of punishment, where and how long did you serve it?
What weather conditions (lighting, audibility) were at the time of the crime?
What is his physical and mental condition? Did you use alcohol (what kind, how much) or drugs the day before (before committing the crime)?
Who owns the objects, valuables, things found during the search?

The ecosystem includes all living organisms (plants, animals, fungi and microorganisms), which, to one degree or another, interact with each other and their inanimate environment (climate, soil, sunlight, air, atmosphere, water, etc.) .).

The ecosystem has no definite size. It can be as big as a desert or a lake, or as small as a tree or a puddle. Water, temperature, plants, animals, air, light and soil all interact together.

The essence of the ecosystem

In an ecosystem, each organism has its own place or role.

Consider the ecosystem of a small lake. In it, you can find all kinds of living organisms, from microscopic to animals and plants. They depend on things such as water, sunlight, air, and even the amount nutrients in water. (Click to learn more about the five basic needs of living organisms).

Lake ecosystem diagram

Every time "foreigner" ( creature(a) or an external factor, such as rising temperatures) are introduced into the ecosystem, catastrophic consequences can occur. This is because the new organism (or factor) is capable of distorting the natural balance of interaction and causing potential harm or destruction to the non-native ecosystem.

Generally, the biotic members of an ecosystem, together with their abiotic factors, depend on each other. This means the absence of one member or one abiotic factor can affect the entire ecological system.

If there is not enough light and water, or if the soil is low in nutrients, the plants may die. If the plants die, the animals that depend on them are also at risk. If animals that depend on plants die, other animals that depend on them will also die. The ecosystem in nature works the same way. All of its parts must function together to maintain balance!

Unfortunately, ecosystems can be destroyed by natural disasters such as fires, floods, hurricanes, and volcanic eruptions. Human activity also contributes to the destruction of many ecosystems and.

Main types of ecosystems

Ecological systems have indefinite dimensions. They are able to exist in a small space, for example, under a stone, a rotting tree stump or in a small lake, and also occupy large areas (like the entire rainforest). From a technical point of view, our planet can be called one huge ecosystem.

Diagram of a small rotting stump ecosystem

Types of ecosystems depending on the scale:

• microecosystem- a small scale ecosystem like a pond, puddle, tree stump, etc.
• mesoecosystem- an ecosystem, such as a forest or a large lake.
• Biome. A very large ecosystem or collection of ecosystems with similar biotic and abiotic factors, such as an entire rainforest with millions of animals and trees, and many different water bodies.

Ecosystem boundaries are not marked with clear lines. They are often separated by geographical barriers such as deserts, mountains, oceans, lakes, and rivers. Since boundaries are not strictly fixed, ecosystems tend to merge with each other. This is why a lake can have many smaller ecosystems with their own unique characteristics. Scientists call this mixing "Ecoton".

Types of ecosystems by type of occurrence:

In addition to the above types of ecosystems, there is also a division into natural and artificial ecological systems. A natural ecosystem is created by nature (forest, lake, steppe, etc.), and an artificial one is created by man (garden, household plot, park, field, etc.).

Ecosystem types

There are two main types of ecosystems: aquatic and terrestrial. Every other ecosystem in the world falls into one of these two categories.

Terrestrial ecosystems

Terrestrial ecosystems can be found anywhere in the world and are subdivided into:

forest ecosystems

These are ecosystems that have an abundance of vegetation or a large number of organisms living in a relatively small space. Thus, the density of living organisms in forest ecosystems is quite high. A small change in this ecosystem can affect its entire balance. Also, in such ecosystems you can find a huge number of representatives of the fauna. In addition, forest ecosystems are divided into:

• Tropical evergreen forests or tropical rainforests: receiving an average rainfall of more than 2000 mm per year. They are characterized by dense vegetation dominated by tall trees located at different heights. These areas are a haven for various kinds animals.
• tropical deciduous forests: Along with a huge variety of tree species, shrubs are also found here. This type of forest is found in quite a few parts of the world and is home to great variety representatives of flora and fauna.
• : They have quite a few trees. It is dominated by evergreen trees that renew their foliage throughout the year.
• Broad-leaved forests: They are located in humid temperate regions that have sufficient rainfall. AT winter months the trees are shedding their leaves.
• : Located directly in front of , the taiga is defined by evergreen coniferous trees, sub-zero temperatures for six months and acidic soils. AT warm time year here you can meet a large number of migratory birds, insects and.

desert ecosystem

Desert ecosystems are located in desert regions and receive less than 250 mm of precipitation per year. They occupy about 17% of the entire land mass of the Earth. Due to extremely high temperature air, poor access to and intense sunlight, and not as rich as in other ecosystems.

grassland ecosystem

Grasslands are located in the tropical and temperate regions of the world. The area of ​​the meadow mainly consists of grasses, with a small number of trees and shrubs. The meadows are inhabited by grazing animals, insectivores and herbivores. There are two main types of meadow ecosystems:

• : Tropical grasslands that have a dry season and are characterized by singly growing trees. They provide food for a large number of herbivores, and are also a hunting ground for many predators.
• Prairies (temperate grasslands): This is an area with a moderate grass cover, completely devoid of large shrubs and trees. In the prairies, forbs and tall grasses are found, as well as arid climatic conditions.
• Steppe meadows: Territories of dry grasslands, which are located near semi-arid deserts. The vegetation of these grasslands is shorter than in the savannas and prairies. Trees are rare, and usually found on the banks of rivers and streams.

mountain ecosystems

The highlands provide a diverse range of habitats where a large number of animals and plants can be found. At altitude, harsh climatic conditions usually prevail, in which only alpine plants can survive. Animals that live high in the mountains have thick fur coats to protect them from the cold. The lower slopes are usually covered with coniferous forests.

Aquatic ecosystems

An aquatic ecosystem is an ecosystem located in aquatic environment(for example, rivers, lakes, seas and oceans). It includes aquatic flora, fauna, and water properties, and is divided into two types: marine and freshwater ecological systems.

marine ecosystems

They are the largest ecosystems that cover about 71% of the Earth's surface and contain 97% of the planet's water. Sea water contains a large amount of dissolved minerals and salts. The marine ecological system is divided into:

• Oceanic (relatively shallow part of the ocean, which is located on the continental shelf);
• Profundal zone (deep water area not penetrated by sunlight);
• Bental region (area inhabited by benthic organisms);
• intertidal zone (a place between low and high tides);
• Estuaries;
• Coral reefs;
• Salt marshes;
• Hydrothermal vents where chemosynthetic feeders.

Many types of organisms live in marine ecosystems, namely: brown algae, corals, cephalopods, echinoderms, dinoflagellates, sharks, etc.

Freshwater ecosystems

Unlike marine ecosystems, freshwater ecosystems cover only 0.8% of the Earth's surface and contain 0.009% of the world's total water supply. There are three main types of freshwater ecosystems:

• Stagnant: Waters where there is no current, such as pools, lakes or ponds.
• Flowing: Fast moving waters such as streams and rivers.
• Wetlands: places where the soil is permanently or intermittently flooded.

Freshwater ecosystems are home to reptiles, amphibians and about 41% of the world's fish species. Fast-moving waters typically contain a higher concentration of dissolved oxygen, thereby supporting more biodiversity than stagnant pond or lake water.

Structure, components and factors of the ecosystem

An ecosystem is defined as a natural functional ecological unit consisting of living organisms (biocenosis) and their inanimate environment (abiotic or physico-chemical), which interact with each other and create a stable system. Pond, lake, desert, pasture, meadow, forest, etc. are common examples of ecosystems.

Each ecosystem consists of abiotic and biotic components:

Ecosystem structure

Abiotic components

Abiotic components are unrelated factors of life or the physical environment that influence the structure, distribution, behavior and interaction of living organisms.

Abiotic components are mainly represented by two types:

• climatic factors which include rain, temperature, light, wind, humidity, etc.
• Edaphic factors, including soil acidity, topography, mineralization, etc.

Importance of abiotic components

The atmosphere provides living organisms with carbon dioxide (for photosynthesis) and oxygen (for respiration). The processes of evaporation, transpiration and occur between the atmosphere and the surface of the Earth.

Solar radiation heats the atmosphere and evaporates water. Light is also essential for photosynthesis. provides plants with energy for growth and metabolism, as well as organic products to feed other life forms.

Most living tissue is made up of a high percentage of water, up to 90% or more. Few cells are able to survive if the water content falls below 10%, and most of them die when the water content is less than 30-50%.

Water is the medium through which mineral food products enter plants. It is also essential for photosynthesis. Plants and animals get water from the Earth's surface and soil. The main source of water is atmospheric precipitation.

Biotic Components

Living things, including plants, animals, and microorganisms (bacteria and fungi) present in an ecosystem are biotic components.

Based on their role in the ecological system, biotic components can be divided into three main groups:

• Producers produce organic substances from inorganic substances using solar energy;
• Consumers feed on ready-made organic substances produced by producers (herbivores, predators, etc.);
• Reducers. Bacteria and fungi that destroy dead organic compounds of producers (plants) and consumers (animals) for nutrition, and emit simple substances (inorganic and organic) into the environment, formed as by-products of their metabolism.

These simple substances are re-produced as a result of cyclical exchange of substances between the biotic community and the abiotic environment of the ecosystem.

Ecosystem levels

To understand the layers of an ecosystem, consider the following figure:

Ecosystem Tier Diagram

Individual

An individual is any living being or organism. Individuals do not breed with individuals from other groups. Animals, unlike plants, are usually included in this concept, since some representatives of the flora can interbreed with other species.

In the diagram above, you can see that gold fish interacts with environment and will breed exclusively with members of its own species.

population

Population - a group of individuals of a given species that live in a particular geographical area in this moment time. (An example is the goldfish and representatives of its species). Note that a population includes individuals of the same species that may have various genetic differences such as coat/eye/skin color and body size.

Community

The community includes all living organisms in a certain area at a given time. It may contain populations of living organisms different types. In the diagram above, notice how goldfish, salmon, crabs, and jellyfish coexist in a particular environment. A large community usually includes biodiversity.

Ecosystem

An ecosystem includes communities of living organisms interacting with the environment. At this level, living organisms depend on other abiotic factors such as rocks, water, air, and temperature.

Biome

In simple terms, it is a collection of ecosystems that have similar characteristics with their abiotic factors adapted to the environment.

Biosphere

When we look at different biomes, each of which transitions into another, a huge community of people, animals and plants is formed, living in certain habitats. is the totality of all ecosystems present on Earth.

Food chain and energy in an ecosystem

All living beings must eat to get the energy they need to grow, move, and reproduce. But what do these living organisms eat? Plants get their energy from the sun, some animals eat plants and others eat animals. This ratio of feeding in an ecosystem is called the food chain. Food chains generally represent the sequence of who feeds on whom in a biological community.

The following are some of the living organisms that can fit in the food chain:

food chain diagram

The food chain is not the same as. The trophic web is a combination of many food chains and is a complex structure.

Energy transfer

Energy is transferred along food chains from one level to another. Part of the energy is used for growth, reproduction, movement and other needs, and is not available for the next level.

Shorter food chains store more energy than long ones. The spent energy is absorbed by the environment.

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Biology test for grade 7

1 option.

Part A. .

1. Chord is preserved in adults

A) lancelets B) fish C) amphibians D) reptiles

2. What ancient animal is considered the ancestor of birds:
A) stegocephalus B) archeopteryx C) trilobite D) pterodactyl 3. Birds of prey must not be destroyed, because they: A) breed poorly B) destroy rodents, sick animals C) serve as food large predators D) feed mainly on fish 4. marine mammals adaptation to life in water: A) developed vision B) large fangs C) streamlined body shape D) thick fur 5. In what animals does the second circle of blood circulation appear in the process of evolution? BUT) cartilaginous fish B) bony fish C) amphibians D) reptiles

6. The lungs as a respiratory organ appear due to:

BUT) increase in movement speed; B) terrestrial habitat; AT) increase in body size; G) changing the way you move.

7.Sense organs characteristic only for fish:

A) hearing B) vision C) lateral line D) touch

8.Mammalian innate reflexes do NOT include:

BUT) salivation at the smell of food; B) executing a simple command; AT) feeding the baby; G) sneezing when hit Airways foreign body.

9. An example of a natural ecosystem is: A) a wheat field B) a greenhouse C) an oak forest D) a greenhouse

10. A mountain hare and a hare living in the same forest make up: A) one population of one species B) two populations of one species C) two populations of two species D) one population of two species

Part C. C1. Choose 3 features characteristic of the Animal Kingdom: A) grow throughout life B) actively move in space C) feed on ready-made organic substances D) form organic substances in the process of photosynthesis E) have sensory organs E) are the main supplier of oxygen on Earth

IN 2. List the order of organisms in the food chain.

A) spider B) starling C) rider D) plant E) aphid E) hawk

AT 3. Set sequence systematic categories, characteristic of the animal kingdom, starting with the smallest.

A) genus B) order C) class D) family E) species E) kingdom

Part C. .

Option 2.

Part A. Choose one of the four answers that is correct..

1. Double (binary) nomenclature for designating species was introduced by: A) Darwin B) Lamarck C) Baer D) Linnaeus 2. K forest birds include:

A) crane B) duck C) woodpecker D) eagle 3. The metabolic rate of birds compared to reptiles: A) lower B) the same as that of crocodiles C) higher ) Cat family C) Bear family D) all of the above 5. Mammals can be distinguished from other vertebrates by the presence of: A) hairline and auricles B) bare skin covered with mucus C) horny shell or scutes D) dry skin with horny scales

6The main types of reproduction in nature are:

BUT) sexual, vegetative; B) asexual, sexual; AT) sexual, cell division in two; G) asexual, vegetative.

7. Closed circulatory system typical for:

A) flatworms B) roundworms; AT) annelids; D) arthropods.

8. Reptiles have a three-chambered heart: A) for all reptiles B) for all but turtles C) for all but crocodiles D) for all but snakes

9. The largest number of species is typical for the ecosystem: A) birch grove B) equatorial forest C) oak forests D) taiga

10. Decomposers, as a rule, include

A) Lower plants B) Invertebrates C) Viruses D) Fungi and bacteria

Part B B1. In insects with complete metamorphosis: A) three stages of development B) four stages of development C) the larva is similar to an adult insect D) the larva differs from the adult insect E) the larva stage is followed by the pupal stage E) the larva turns into an adult insect

IN 2. Select abiotic environmental factors:

A) deforestation B) water salinity C) symbiosis of fungi and higher plants D) species diversity E) air temperature E) sea currents

B3 Set the sequence of systematic categories characteristic of the animal kingdom, starting with the largest.

A) genus B) species C) kingdom D) family E) order E) class

Part C. What is natural selection?

Answers to control work. 7th grade

Part C. Option 1. Why are dolphins classified as mammals and not fish? Dolphins are mammals, because. they have: 1. feed their young with milk 2. respiratory organs are lungs, not gills

Part C. Option 2. What is natural selection?

Natural selection- this is the survival of the organisms most adapted to environmental conditions and the destruction of the unadapted.

Before giving the concept of an ecosystem, let us turn to the definition of biocenosis and biogeocenosis. Biocenosis- a set of cohabiting populations of different species of microorganisms, plants and animals. The term "biocenosis" was first used by Möbius (1877), studying a group of organisms in an oyster bank, that is, from the very beginning this community of organisms was limited to a certain geographical space, in this case, the boundaries of a shallow. Later this space was called a biotope. Biotope is a homogeneous area of ​​land or water inhabited by living organisms. The components of the biotope do not just exist side by side, but actively interact with each other, creating a certain biological system, which Academician V.N. Sukachev called biogeocenosis. In this system, the totality of biotic and abiotic components has its own, special specifics of interactions and a certain type of exchange of matter and energy between themselves and other natural phenomena, which is a contradictory internal dialectical unity that is in constant motion and development. (Sukachev, 1971).

However, a little earlier, in 1935, the term "ecosystem" was introduced by the English botanist A. Tensley. Ecosystem- this is a set of different types of organisms living together and the conditions of their existence, which are in a regular relationship with each other, or a set of complexes of organisms with a complex of physical factors of its environment, that is, habitat factors in a broad sense. The largest ecosystem is the biosphere of the Earth, further in decreasing order: land, ocean, tundra, taiga, forest, lake, tree stump, flower pot. Despite the fact that, at first glance, the concepts of "ecosystem" and "biogeocenosis" may seem identical, in fact they are not. An ecosystem is the unity of organisms and the environment of existence, while biogeocenosis is a combination of the unity of organisms and the conditions of existence. The biogeocenosis includes only biological objects within the phytocenosis, which arise and exist on the basis of a single biological cycle of substances in this system. The organism's environment includes other organisms, physical factors, chemical factors, geographic processes and phenomena, human activities, as well as relief and climate (according to A. Tensley).

Let's try to highlight the differences between biogeocenosis and ecosystems:

according to system-forming relationships - in biogeocenosis there is a causal interaction of such opposites as organisms and the conditions for their existence. They mutually generate, mutually change and determine the existence of each other. The ecosystem consists of a variety of objects, united by correlations, they do not give rise to each other;

biogeocenosis is the carrier of the biological form of the movement of matter. The entire content of this system arises and exists only on the basis of biological metabolism. In an ecosystem there is no common reason for the existence of its components, there is no single process that would give rise to its components.

Schematically, the following can be shown:

Classifications of natural systems of the biosphere are based on the landscape approach, since ecosystems are an integral part of natural geographical landscapes that form the geographic (landscape) shell of the Earth. Biogeocenoses form on the surface of the Earth the so-called biogeosphere, which is the basis of the biosphere, which V.I. Vernadsky called the "film of life", and V.N. Sukachev - "biogeocenotic cover".

Landscape- this is a natural geographical complex in which all the main components (upper horizons of the lithosphere, relief, climate, water, soil, biota) are in complex interaction, forming a single system that is homogeneous in terms of development.

The landscape approach in ecology is, first of all, of great importance for the purposes of nature management. By origin, two main types of landscapes are distinguished - natural and anthropogenic.

natural landscape It is formed exclusively under the influence of natural factors and is not transformed by human economic activity. Initially, the following natural landscapes were distinguished:

- geochemical- denotes a site allocated on the basis of the unity of the composition and quantity of chemical elements and compounds;

- elemental landscape denotes an area composed of certain rocks located on the same relief element, in equal conditions for the occurrence of groundwater, with the same nature of plant associations and one type of soil;

- protected landscape, where all or certain types of economic activity are regulated or prohibited in the prescribed manner.

Anthropogenic landscape - this is a former natural landscape, transformed by economic activity so much that its connection has been changed natural ingredients. Landscapes include:

- agricultural(agricultural) - whose vegetation has been largely replaced by crops and plantings of agricultural and horticultural crops;

- technogenic, the structure of which is determined by man-made human activities associated with the use of powerful technical means (land disturbance, pollution by industrial emissions). This includes the industrial landscape. , formed as a result of the impact on the environment of large industrial complexes;

- urban(urban) - with buildings, streets and parks.

The biome is characterized by a certain type of community structure, which expresses a complex of adaptation to environmental conditions. The main types of terrestrial and aquatic biomes are presented in tabular form (Table 3.1).

Table 3.1 - Classification of ecosystems on a landscape basis

ecosystems
Ground
	freshwater
Coniferous forest (taiga); Deciduous forest; Wet tropical forests; Desert; Savannah.	Lentic (lat. lentes - calm; lakes, ponds, etc.); Lotic (lat. lotus - washing; rivers, streams, springs); Wetlands (swamps, marshy forests).	Open ocean (pelagic); Continental shelf waters (coastal waters); Deep water reef zones; Upwelling areas - fertile areas with productive fishing); Estuaries (coastal bays, straits, river mouths, salt marshes, etc.).

Terrestrial ecosystems

Tundra- this is a biome located in the Arctic zone of the Earth (this is the north of Eurasia and North America), formed in a cold climate. It is characterized by the presence of permafrost, treelessness, powerful development of moss and lichen covers, and waterlogging. The average rainfall does not exceed 250 mm per year. Plants are low-growing, mostly perennial (lichens, mosses, grasses, shrubs and dwarf shrubs), plant growth is slow. The fauna is not rich, the number of sedentary species is small. Of the mammals, the most important are reindeer, arctic fox, rodents (primarily lemmings), wolves, white hare. Waterfowl predominate among the birds. Insects are plentiful, especially blood-sucking (gnats). Food chains are relatively short, so a change in one of the trophic levels strongly affects others, causing sharp fluctuations in numbers. Tundra ecosystems are considered to be vulnerable and fragile, especially under anthropogenic pressure.

coniferous forest (taiga) formed under conditions of a relatively short frost-free period (about four months), cold winters with stable snow cover and precipitation exceeding evaporation (up to 750 mm per year). On Earth, about 10% of the land is occupied by taiga. Compared with tropical forests the taiga is poor in species and life forms. The tree layer consists mainly of coniferous tree species, however, derivative, deciduous forests (mainly birch and aspen) grow in places of fires and clearings. The development of the shrub and grass layer depends on the illumination under the forest canopy (in spruce and fir forests, the undergrowth is rare, and in pine and larch forests it is well expressed). Mammals characteristic of the entire forest zone live here: elk, bear, lynx, sable, marten, squirrel, badger, chipmunk and others. Typical birds: capercaillie, hazel grouse, nutcracker, crossbills, woodpeckers, owls and others. Many insects are associated with coniferous trees: pine silkworm, longhorn beetles, bark beetles, taiga ant species and others. Abundant filth. Significant resources of timber, food and medicinal raw materials are concentrated in the taiga, and intensive hunting is carried out.

deciduous forest- biome occupying southern part forest geographical zone of the temperate zone. It differs from the taiga in a large number of species of animals and plants living here. The main dominant tree species are deciduous. The tiering is well expressed, while the tiers are often divided into sub-tiers. Of the animals, in addition to those found in the taiga, various types of deer, roe deer and wild boar are characteristic. The number and species diversity of birds and insects is increasing. Deciduous forests are also subject to intensive human activities.

Tropical rainforests distributed in the equatorial, tropical and subtropical zones of the Earth - in South America, Africa, Southeast Asia, New Guinea and Oceania. They occupy an area of ​​approximately 30 million square meters. km, develop in conditions of excess moisture and heat. Precipitation here falls more than 2400 mm per year. common tree species plants that predominate over herbaceous. Trees bloom, bear fruit and change leaves throughout the year. The tiers of the forest stand are practically not expressed, shrubs are most often absent, and the grass cover is poor. Flora and fauna are extremely rich. About 80% of all plant species grow here. A diverse animal population is concentrated mainly in the crowns of trees. Mammals are characterized by monkeys (including anthropoids: chimpanzees, gorillas, orangutans, gibbons) and large predators: leopard, tiger, jaguar. From birds - parrots, hummingbirds, toucans and so on. Lots of amphibians and reptiles. Invertebrates, especially insects, are extremely diverse. Biocenoses rainforest most productive on our planet. Occupying about 6% of the earth's land, they provide more than 28% of the total production of organic matter. Due to intensive washing and the abundance of invertebrates and fungi that destroy the litter, the soils of tropical forests are poor - they contain much less humus than in the forests of the temperate zone. The humid tropical forest plays an exceptional role in the normal functioning and development of the entire biosphere, maintaining its water and gas regime, preserving the diversity of life forms. As a result of human activity, the area of ​​tropical forests is constantly declining, which indicates the need for significant efforts to protect them.

Steppe- this is a type of biome that has developed in conditions of a long hot summer and more or less cold winter with a rainfall of 200 to 500 mm per year. Steppes occupy vast territories in Eurasia, form an altitudinal belt in the mountains, their analogues in North America are prairies, in South America- pampas. Of the plants, perennial frost- and drought-resistant grasses (mainly cereals) predominate. Soils are characterized by the formation of a fertile layer that is significant in thickness. Many gregarious ungulates and rodents. The abundance of rodents attracts birds of prey and mammals. The steppes are widely used by man for the development of agriculture and grazing, as a result of which they are now almost completely developed and converted into agricultural land.

In areas with extremely dry climates, desert - biomes with very sparse and depleted vegetation cover. The amount of precipitation here does not exceed 200 mm per year (with high evaporation). Deserts occupy about a third of the land area on all continents. The share of the area covered with vegetation does not exceed 10 - 20%. In the most arid regions, higher plants are absent in large areas. Desert plants are adapted to long-term existence with minimal moisture reserves (for example, cacti, prickly pear and spurges, which store moisture in the plant body, or saxaul, which has a very long root and reaching aquifers). The exception is the Arctic deserts, which depend not on the dryness of the climate, but on low temperatures. Mostly mosses and lichens live there. The desert fauna as a whole is characterized by a fairly large number of mammal species, mainly rodents (jerboas, ground squirrels, gerbils, and others). There are ungulates (kulan, goitered gazelle) and predators (wolf, coyote, corsac fox, dune cat and others). Camels live in the deserts of Eurasia, and vicuñas and guanacos live in South America (in the domesticated state, respectively, alpaca and llama). Of the birds, the beauty bustard, hazel grouse, and larks are interesting. Lots of reptiles, insects and arachnids. The area of ​​deserts is constantly increasing both for natural reasons and under the influence of human activities.

It should be noted that along with the main types of biomes there are many transitional options: forest-tundra, forest-steppe, coniferous-deciduous forest, semi-desert and others. Of particular interest is savannah - transitional zone between tropical forests and deserts. The savanna develops in conditions of a clear change of dry and rainy seasons with little precipitation (like in the steppe). It occupies about 40% of the area of ​​Africa, is found in South America, South Asia, and Australia. It is characterized by an abundance of grass cover. Trees are sparse, far apart, shrubs are found in depressions. The abundance of plant foods contributes to the existence of a rich animal population, especially large herbivores - antelopes, giraffes, buffaloes, elephants, zebras, kangaroos (in Australia), as well as carnivores - lions, cheetahs, etc. There are many rodents, running birds (ostriches), reptiles and insects.

It is important to note that on our planet there is a change of biomes in the latitudinal (from south to north) and vertical (when climbing mountains) directions.

Freshwater ecosystems

lakes- natural freshwater reservoirs, formed geologically relatively recently - over the past few tens of thousands of years, and only some of them are millions of years old, for example, Baikal. The presence of a profundal zone in most lakes (the profundal zone is the bottom and the water column where sunlight does not penetrate) affects the temperature regime of the water column, its mixing and the distribution of oxygen in it. These processes are seasonal, as is the stratification (stratification) of the lake according to the temperature regime.

Ponds have a well-developed littoral (littoral zone - the water column where sunlight reaches the bottom) and a practical absence of stratification, they are formed in various depressions, often temporarily dry up in summer or in dry years. The fauna of ponds is able to survive dry periods in a dormant state or move to other water bodies (amphibians). Natural ponds are highly productive. In artificial ponds, basically, a person feeds the fish himself.

reservoirs are created by man during the construction of hydropower and hydro-reclamation complexes. This is no longer a natural ecosystem, but a natural-technical system. The distribution of heat and nutrients in it depends on the type of dam. If the bottom water is discharged, then in this case the reservoir accumulates heat and exports nutrients , if the discharge goes over the dam, then heat is exported and nutrients are accumulated. In the first case, the water of the hypolimnion descends (hypolimnion - an area of ​​cold water where there is no circulation), in the second - epilimnion (epilimnion - the depth where water circulation occurs). More saline water also enters the river through deep-water locks, and nutrients cause eutrophication (oversaturation of water with nutrients) of the river section.

The listed freshwater ecosystems belong to tapering.

Lotic ecosystems - rivers- differ from stagnant water bodies in three main conditions: 1) currents are an important limiting and controlling factor; 2) the exchange between water and land is much more active; 3) the distribution of oxygen is more uniform, since there is practically no stratification. Current speed affects the distribution of fish in rivers - they can live under stones, and in creeks, under rifts, but these will be different species adapted to specific conditions. The river is an open ecosystem, which receives a large amount of organic matter from adjacent spaces.

Wetlands in freshwater – swamps- lowlands and highlands. Lowland are usually fed by groundwater; and riding - atmospheric precipitation. Riding can be found in any depression or even on the slopes of mountains, lowlands arise as a result of the overgrowth of lakes and river oxbows. They are covered with aquatic macrophytes, marsh plants and shrubs.

Wetlands and peatlands contain a lot of carbon (14 - 20%), the agricultural development of which leads to the release of a large amount of carbon dioxide into the atmosphere, which exacerbates the CO 2 problem.

marine ecosystems

open ocean one of the largest ecosystems (94% of the hydrosphere). The living environment of the ocean is continuous, there are no boundaries in it that prevent the resettlement of living organisms (on land, the boundary is the ocean between the continents, on the mainland - rivers, mountains, etc.). In the ocean, water is in constant motion. There are horizontal and vertical currents. Dissolved in water - 48-10 tons of salts.

These physical and chemical features create favorable conditions for the formation and development of various organisms. The ocean contains:

150,000 species of animals (this is about 7% of their total number).

10,000 plant species (this is about 8% of their total number). Basically, various types of algae.

However, organic life is unevenly distributed horizontally and vertically. Depending on abiotic factors (light regime, temperature, salinity, and so on), the ocean is divided into several zones.

Depending on lighting:

- upper illuminated - up to 200 m (euphotic);

Lower, devoid of light - over 200 m (aphotic).

The ocean ecosystem is also divided into:

Water column (pelagial);

Bottom (bental).

Depending on depth:

Up to 200 m (littoral zone);

Up to 2500 m (batyal zone);

Up to 6000 m (abyssal zone);

More than 6000 m (ultraabyssal zone).

In the open ocean, compared to the coastal zone, food is less concentrated, so there are a variety of actively swimming organisms (fish, squid, sharks, whales, and so on.).

coastal zone has optimal conditions for life compared to the open ocean (light, temperature, sufficient nutrients) - therefore, the maximum species diversity of flora and fauna is observed here (up to 80%).

deep water reef zone ocean was discovered in 1977 in the zone of the underwater ridge of the Pacific Ocean to the northeast of the Galapagos Islands. Here, at a depth of 2600 m, there are "oases of life" - giant worms (up to 1.5 m), large white mollusks, shrimps, crabs, and certain types of fish. The very high density of biomass is striking - up to 15 kg / m, in other places at the same depth - up to 0.01 kg / m (1500 times more). The deep-water zone is characterized by complete darkness, enormous pressure. Adaptation - reduction of the swim bladder, organs of vision, development of organs of luminescence, and the like. In the reef zone, in addition to complete darkness, a high content of hydrogen sulfide and toxic metals, there are outlets of thermal springs. Similar areas are found in other areas of the ocean.

In this ecosystem, sulfur bacteria play the role of plants, using hydrogen sulfide and sulfur compounds instead of sunlight (chemosynthesis). Sulfur bacteria - the first link in the food chain, then - pogonophores, inside the body of which live bacteria that process hydrogen sulfide and supply the body with the necessary nutrients. Also, mollusks exist in symbiosis with sulfur bacteria.

Upwelling regions most productive in the oceans. Upwelling is the process of raising cold water from the depths of the ocean where winds constantly move water away from a steep continental slope, in exchange for which nutrient-rich water rises from the depths. Upwelling areas are located along the western desert coasts of the continents. They are rich in fish and birds living on the islands. But when the direction of the wind changes, the plankton bloom decreases and there is a mass death of fish due to the development of anoxic conditions - eutrophication.

Biotic structure of the ecosystem. Despite the enormous diversity of ecosystems - from tropical forests to deserts, forests, swamps, lakes, they are characterized by the same biotic structure. All ecosystems include the same basic categories of organisms interacting with each other. These are producers (autotrophs), consumers (heterotrophs), decomposers (mixotrophs).

Producers - these are mainly green plants (unicellular algae, grasses, trees, and so on), as well as chemosynthetic and autotrophic bacteria. Their main function is to create organic matter from minerals through photosynthesis. Photosynthesis is a chemical reaction that takes place with the participation of chlorophyll cells of green plants using solar energy, carbon dioxide, water and solar energy. In this case, the formation of glucose (the simplest of sugars) and oxygen. Photosynthesis takes place in every cell of green leaves.

6CO 2 +6 H 2 O + Q \u003d C 6 H 12 O 6 + 6O 6

Oxygen is released into the atmosphere. From glucose and mineral elements, plants synthesize complex substances that make up the body (proteins, fats, carbohydrates, DNA).

Plants produce complex organic compounds from simple inorganic ones. At the same time, solar energy is accumulated in organic compounds along with chemical elements.

Consumers. Animals feed on organic matter, using it as a source of energy and material for the formation of their bodies. Green plants produce food for other organisms in the ecosystem. It is customary to distinguish first-order consumers - phytophages (phyto-plants, phage-eater) and second-order consumers - zoophages. There are consumers of the third, fourth and higher orders. The hare eats carrots - the primary consumer, the fox that ate the hare - the secondary consumer. Man - eats vegetables - the primary consumer, and meat - secondary, predatory fish (pike) - the third order.

decomposers- these are organisms that feed on dead plant and animal remains, they can also be called detritophages (fallen leaves, feces, dead animals - this is called detritus). Their task is the processing of dead residues and waste products to minerals. These are fungi and bacteria. Feeding on dead organic matter, detritophages decompose it. When they die, they themselves become part of the detritus.

Some organisms do not fit into this scheme. For example: insectivorous plants. They catch insects, partially digest them with the help of enzymes and organic acids, as a result of which they make up for the lack of nitrogen and other nutrients. In Russia, there are about 20 species of them (venereal flycatcher, sarracenia, sundew). Such plants live in places with a lack of nitrogen, phosphorus, potassium (bogs are very poor in nutrients).

food web. trophic levels. When studying the biotic structure of an ecosystem, it becomes obvious that one of the most important relationships between organisms is food. It is possible to trace countless ways of the movement of matter in an ecosystem, in which one organism is eaten by another, and that one by a third, and so on.

The food chain is the path of movement of matter (energy source and building material) in an ecosystem from one organism to another.

plant beetle frog snake bird

In nature, food chains are rarely isolated from each other. Much more often, representatives of one species (herbivores) feed on several types of plants, and themselves serve as food for several species. Despite the variety of food webs, they all correspond general scheme: from green plants to primary consumers, from them to secondary consumers, and so on and to detritophages. In last place are always detritophages, they close the food chain.

A trophic level is a set of organisms that occupy a certain place in the food web. Detritophages can be at the second and higher trophic level. Typically, there are three to four trophic levels in an ecosystem. This is due to the fact that a significant part of the food consumed is spent on energy (90 - 99%), so the mass of each trophic level is less than the previous one. Relatively little goes to the formation of the body of the organism (1 - 10%). The ratio between plants, consumers, detritophages is expressed in the form of pyramids (graphically).

Biomass pyramid - shows the ratio of biomasses of various organisms at trophic levels.

Energy Pyramid - Shows the flow of energy through an ecosystem.

Obviously, the existence of a greater number of trophic levels is impossible due to the rapid approach of biomass to zero.

Autotrophs are the first link in the food chain and are at the first trophic level. Heterotrophs are at the second and higher trophic level. Figure 3.1 shows an example of a biomass pyramid.

Figure 3.1 - Pyramid of biomass

ecological succession. Y. Odum (1986) under ecological succession understands the entire process of ecosystem development. A more specific definition is given to this phenomenon by N. F. Reimers (1990): « Succession is a successive change of biocenoses that occurs in the same territory (biotope) under the influence of natural factors (including internal contradictions of the biocenoses themselves) or human impact. Changes in the community as a result of succession are of a regular nature and are due to the interaction of organisms with each other and with the surrounding abiotic environment.

Free space is needed for succession to occur. Depending on the initial state of the substrate, there are primary and secondary successions. primary succession - this is if the formation of communities begins on an initially free substrate, and secondary succession - this is a successive replacement of one community that existed on a given substrate by another, more perfect for given abiotic conditions.

primary succession allows you to trace the formation of communities from the very beginning. It can occur on a slope after a landslide or collapse, on a formed shallow during the retreat of the sea and a change in the course of the river, on the exposed sands of the desert, not to mention anthropogenic disturbances: a fresh cutting area, an alluvial strip of the sea coast, artificial reservoirs.

An example of primary succession is the overgrowth

spruce forest of new territories in the north of our country. Elnik is the last climax stage of ecosystem development in the climatic conditions of the North, i.e. already a radical biocenosis . At first, birch forests, alder forests, and aspen forests develop here, under the canopy of which spruce trees grow. Gradually, they outgrow the birch and displace it, capturing space (Fig. 3.2).

Figure 3.2 - Change of birch forest to spruce forest

A successive series of communities gradually and regularly replacing each other in succession is called a succession series. It is observed in nature not only in forests, swamps and lakes, but also on the trunks of dying trees and in stumps, where a regular change of saprophytes and saprophages occurs, in puddles and ponds, and so on. Successions are multiscale and hierarchical, just like the ecosystems themselves.

The state of final equilibrium or homeostasis of a community is called menopause. Yu. Odum gave the following definition: a climax community is a self-sustaining community that is in balance with the physical habitat. It can also be said that the climax is the final relatively stable phase of the natural development of a biogeocenosis or plant community, which is most consistent with the ecological characteristics of a given area in a certain period of geological time.