Properties of living organisms

1. Metabolism and energy with the environment (the main sign of living things).

2. Irritability(ability to respond to influences).

3. Reproduction(self-reproduction).

Levels of organization of living matter

1. Molecular- this is the level of complex organic substances - proteins and nucleic acids. At this level there are chemical metabolic reactions(glycolysis, crossing over, etc.), but the molecules themselves cannot yet be considered alive.

2. Cellular. At this level there is life, because a cell is the minimum unit that has all the properties of a living thing.

3. Organ-tissue- characteristic only of multicellular organisms.

4. Organic- due to neurohumoral regulation and metabolism at this level, it is carried out homeostasis, i.e. maintaining the constancy of the internal environment of the body.

5. Population-species. At this level it happens evolution, i.e. changes in organisms associated with their adaptation to their environment under the influence of natural selection. The smallest unit of evolution is the population.

6. Biogeocenotic(a set of populations of different species connected with each other and the surrounding inanimate nature). At this level it happens

circulation of substances and energy conversion, and
self-regulation, due to which the stability of ecosystems and biogeocenoses is maintained.

7. Biosphere. At this level it happens

global cycle substances and energy conversion, and
interaction between living and nonliving matter planets.

Choose two correct answers out of five and write down the numbers under which they are indicated. At what levels of living organization do they study the significance of photosynthesis in nature?
1) biosphere
2) cellular
3) biogeocenotic
4) molecular
5) tissue-organ

Answer

Choose one, the most correct option. What level of organization of living nature is a collection of populations of different species connected with each other and the surrounding inanimate nature
1) organismic
2) population-species
3) biogeocenotic
4) biosphere

Answer

Choose one, the most correct option. Gene mutations occur at the level of organization of living things
1) organismal
2) cellular
3) species
4) molecular

Answer

Choose one, the most correct option. The elementary structure at the level of which the action of natural selection manifests itself in nature
1) organism
2) biocenosis
3) view
4) population

Answer

Choose two correct answers out of five and write down the numbers under which they are indicated. What signs are similar for living and nonliving objects of nature?
1) cellular structure
2) change in body temperature
3) heredity
4) irritability
5) movement in space

Answer

Choose two correct answers out of five and write down the numbers under which they are indicated. At what levels of the organization of living things are the characteristics of photosynthesis reactions studied in higher plants?
1) biosphere
2) cellular
3) population-species
4) molecular
5) ecosystem

Answer

Below is a list of concepts. All of them, except two, are levels of organization of living things. Find two concepts that “fall out” from the general series and write down the numbers under which they are indicated.
1) biosphere
2) genetic
3) population-species
4) biogeocenotic
5) biogenic

Answer

1. Establish the sequence in which the levels of organization of living things are located. Write down the corresponding sequence of numbers.
1) population
2) cellular
3) species
4) biogeocenotic
5) molecular genetic
6) organismic

Answer

2. Establish a sequence of increasing complexity of the levels of organization of living things. Write down the corresponding sequence of numbers.
1) biosphere
2) cellular
3) biogeocenotic
4) organismic
5) population-species

Answer

1. Choose two correct answers out of five and write down the numbers under which they are indicated. The cellular level of organization coincides with the organismal level
1) bacteriophages
2) dysenteric amoeba
3) polio virus
4) wild rabbit
5) green euglena

Answer

2. Select two correct answers out of five and write down the numbers under which they are indicated in the table. They simultaneously correspond to the cellular and organismal levels of life organization.
1) freshwater hydra
2) spirogyra
3) ulotrix
4) dysenteric amoeba
5) cyanobacterium

Answer

3. Choose two correct answers. Which organisms have the same cellular and organismal levels of life?
1) sulfur bacteria
2) penicillium
3) chlamydomonas
4) wheat
5) hydra

Answer

Choose two correct answers out of five and write down the numbers under which they are indicated. One common amoeba is simultaneously located on:
1) Molecular level of life organization
2) Population-species level of life organization
3) Cellular level of life organization
4) Tissue level of life organization
5) Organismal level of life organization

Answer

1. Choose two correct answers out of five and write down the numbers under which they are indicated. Living things differ from non-living things
1) the ability to change the properties of an object under the influence of the environment
2) the ability to participate in the cycle of substances
3) the ability to reproduce their own kind
4) change the size of an object under the influence of the environment
5) the ability to change the properties of other objects

Answer

2. Choose two correct answers out of five and write down the numbers under which they are indicated. What characteristics are unique to living matter?
1) height
2) movement
3) self-reproduction
4) rhythmicity
5) heredity

Answer

3. Choose two correct answers out of five and write down the numbers under which they are indicated. Characteristic of all living organisms
1) the formation of organic substances from inorganic
2) absorption of minerals dissolved in water from the soil
3) active movement in space
4) breathing, nutrition, reproduction
5) irritability

Answer

4. Choose two correct answers out of five and write down the numbers under which they are indicated. What features are characteristic only of living systems?
1) ability to move
2) metabolism and energy
3) dependence on temperature fluctuations
4) growth, development and ability to reproduce
5) stability and relatively weak variability

Answer

5. Choose two correct answers out of five and write down the numbers under which they are indicated. Organisms, unlike objects of inanimate nature, are characterized by
1) change
2) movement
3) homeostasis
4) evolution
5) chemical composition

Answer

Establish a correspondence between the levels of organization of living things and their characteristics and phenomena: 1) biocenotic, 2) biosphere. Write numbers 1 and 2 in the order corresponding to the letters.
A) processes cover the entire planet
B) symbiosis
B) interspecific struggle for existence
D) transfer of energy from producers to consumers
D) evaporation of water
E) succession (change of natural communities)

Answer

Choose two correct answers out of five and write down the numbers under which they are indicated. Ontogenesis, metabolism, homeostasis, reproduction occur at ... levels of organization.
1) cellular
2) molecular
3) organismal
4) organ
5) fabric

Answer

Choose two correct answers out of five and write down the numbers under which they are indicated in the table. At the population-species level, the organization of life is
1) fish of Lake Baikal
2) birds of the Arctic
3) Amur tigers of Primorsky Krai of Russia
4) city sparrows of the Park of Culture and Recreation
5) tits of Europe

Answer

Choose two correct answers out of five and write down the numbers under which they are indicated in the table. Which levels of life organization are supraspecific?
1) population-species
2) organoid-cellular
3) biogeocenotic
4) biosphere
5) molecular genetic

Answer

Choose two correct answers out of five and write down the numbers under which they are indicated. Corresponds to the cellular level of life organization
1) chlamydomonas
2) sulfur bacteria
3) bacteriophage
4) kelp
5) lichen

Answer

Choose two options. Energy exchange in the common amoeba occurs at the level of organization of living things.
1) cellular
2) biosphere
3) organismal
4) biogeocenotic
5) population-species

Answer

Choose two correct answers out of five and write down the numbers under which they are indicated. At what level of organization do processes such as irritability and metabolism occur?
1) population-species
2) organismic
3) molecular genetic
4) biogeocenotic
5) cellular

Answer

Introduction

Individuals in nature are not absolutely isolated from each other, but are united by a higher rank of biological organization. This is the population-species level. It arises where and when individuals unite into populations, and populations into species. Populations are a collection of individuals of the same species inhabiting a certain area, more or less isolated from neighboring populations of the same species. Such associations are characterized by the emergence of new properties and features in living nature, different from the properties of the molecular genetic and ontogenetic levels.

The purpose of the study predetermined the formulation of the following interrelated tasks:

Reveal the features of the forms of interaction between organisms in the population;

Populations and species, despite the fact that they consist of many individuals, are integral. But their integrity is based on other grounds than integrity at the molecular genetic and ontogenetic levels. The integrity of populations and species is ensured by the interaction of individuals in populations and is recreated through the exchange of genetic material in the process of sexual reproduction. Populations and species as supra-individual formations are capable of existing for a long time and of independent evolutionary development. The life of an individual depends on the processes occurring in populations.

Populations act as elementary, further indecomposable evolutionary units, which are genetically open systems (individuals from different populations sometimes interbreed and populations exchange genetic information). At the population-species level, the processes of panmixia (free crossing) and relationships between individuals within the population of a species acquire a special role. Species, which always act as a system of populations, are the smallest, genetically closed systems under natural conditions (crossing of individuals of different species in nature in the vast majority of cases does not lead to the appearance of fertile offspring). All this leads to the fact that populations turn out to be elementary units, and species - qualitative stages of the evolutionary process.

A population is the basic elementary structure at the population-species level, and an elementary phenomenon at this level is a change in the genotypic composition of the population; elementary material at this level - mutations. The synthetic theory of evolution identifies elementary factors operating at this level: the mutation process, population waves, isolation and natural selection. Each of these factors can exert one or another “pressure”, i.e. the degree of quantitative impact on the population, and depending on this, cause changes in the genotypic composition of the population.

Populations and species always exist in a certain systemically organized natural environment, which includes both biotic and abiotic factors. Such natural systems external to populations and species form another level of organization of living things - biogeocenotic.

Populations of different species interact with each other. During interaction, they unite into complex systems - biocenoses.

Biocenosis is a collection of plants, animals, fungi and microorganisms inhabiting an area of the environment with more or less homogeneous living conditions and characterized by certain relationships between themselves and the living environment. The components that form a biocenosis are interdependent. Changes affecting only one species can affect the entire biocenosis and even cause its collapse. Biocenoses are included as components in even more complex systems (communities) - biogeocenoses.

Biogeocenosis (ecosystem, ecological system) is an interdependent complex of living and abiotic components interconnected by metabolism and energy. Biogeocenosis is one of the most complex natural systems. Biogeocenoses are a product of the joint historical development of species that differ in systematic position; species thus adapt to each other. Biogeocenoses are an environment for the evolution of their constituent populations.

Biogeocenosis is an integral system. The loss of one or more components of a biogeocenosis can lead to the destruction of the integrity of the biogeocenosis in the cycle of substances, which often leads to an irreversible imbalance and death of the biogeocenosis as a system. The structure of biogeocenosis changes during the evolution of species: species in a biogeocenosis act on each other not only according to the principle of direct, but also feedback (including through their changes in abiotic conditions). In general, the life of a biogeocenosis is regulated mainly by forces acting within the system itself, i.e. we can talk about self-regulation of biogeocenosis. Biogeocenosis is an open system that has energy “inputs” and “outputs” that connect neighboring biogeocenoses. The exchange of substances between neighboring biogeocenoses can take place in the gaseous, liquid and solid phases, as well as in the form of animal migration.

Biogeocenosis is a balanced, interconnected and time-stable system, which is the result of long-term and deep adaptation of its constituent components. This is a very dynamic and at the same time stable community. The stability of a biogeocenosis is proportional to the diversity of its components. The more diverse the biogeocenosis, the more stable it is, as a rule, in time and space. For example, biogeocenoses represented by tropical forests are much more stable than biogeocenoses in the temperate or arctic zones, since tropical biogeocenoses consist of a much larger variety of plant and animal species than temperate and especially arctic biogeocenoses.

Highly organized organisms require simpler organisms for their existence; Every ecosystem invariably contains both simple and complex components. A biogeocenosis consisting only of bacteria or trees can never exist, just as it is impossible to imagine an ecosystem inhabited only by vertebrates or mammals. Thus, lower organisms in an ecosystem are not some random relic of past eras, but a necessary component of biogeocenosis, an integral system of the organic world, the basis of its existence and development, without which the exchange of matter and energy between the components of biogeocenosis is impossible. The primary basis for the formation of biogeocenoses are plants and microorganisms, producers of organic matter (autotrophs). In the course of evolution, until a certain space of the biosphere is populated by plants and microorganisms, there can be no question of populating it with animals. Plants and microorganisms provide a living environment for animals - heterotrophs. Therefore, the boundaries of biogeocenoses most often coincide with the boundaries of plant communities (phytocenoses). Subsequently, animals play an important role in the life and evolution of plants, participating in the cycle of substances, pollination, distribution of fruits, etc.

The entire set of biogeocenoses interconnected by the circulation of substances and energy on the surface of our planet form a powerful system of the Earth’s biosphere. The upper limit of life in the atmosphere reaches approximately 30 km, the largest number of organisms is found at an altitude of up to 100 m. In the depths of the Earth (lithosphere), the bulk of creatures are concentrated in the very top layer - up to 10 m, although certain types of microorganisms are found in oil-bearing layers at a depth up to 3 km. In the ocean and seas (hydrosphere), a zone rich in living organisms occupies a layer of water up to 100 - 200 m, but some organisms are also found at a maximum depth of up to 11 km. The scale of activity of living organisms is evidenced by the presence of thick biogenic rocks, thousand-meter thick layers of limestone, huge deposits of coal, etc. Considering the Earth's biosphere as a single ecological system, one can be convinced that the living matter of the Earth does not significantly decrease or increase in mass, but only passes from one state to another.

The branch of biology that studies ecological systems (biocenoses, biogeocenoses, biosphere) is called biogeocenology. Its founder was our outstanding domestic scientist V.N. Sukachev.

I. Populations of different species do not exist in nature separately, but are interconnected by various relationships. Thanks to this, they are formed communities - certain sets of populations of different species that are interconnected. Each species can exist in the form of populations only through connections with populations of other species. As a result of these relationships between species inhabiting a site with homogeneous living conditions, biocenoses are formed.

Biocenosis- a community of interconnected populations of organisms of various species inhabiting an area of terrain with homogeneous living conditions. The basis of biocenoses are photosynthetic organisms (mainly green plants). Plant component of the community biocenosis - phytocenosis - determine the boundaries of the biocenosis (for example, the biocenosis of a pine forest, feather grass steppe). Aquatic biocenoses are located in homogeneous areas of water bodies (for example, biocenoses of the tidal zone). Each biocenosis is characterized by a certain species diversity, biomass, productivity, density of species populations, area or volume that it occupies.

Species diversity of biocenosis determined species richness - the number of species whose populations are included in its composition and evenness - the ratio between the population sizes of each of them. There are biocenoses with low (deserts, tundra) and rich (tropical forests, coral reefs) species diversity. The species included in the biocenosis have different numbers. The most numerous species are called dominant . They determine the nature of the biocenosis as a whole (for example, feather grass species in the feather grass steppe, oak and hornbeam in the oak-hornbeam forest).

Biomass of the biocenosis- the total mass of individuals of different species expressed per unit area or volume. Each biocenosis is characterized by a certain productivity - biomass created per unit of time. There are primary and secondary productivity. Primary productivity - this is the biomass created per unit of time by autotrophic organisms, secondary - heterotrophic.

II. Each biocenosis has a certain structure: species, spatial, ecological.

1. Species structure due to both species diversity.

2. Spatial structure determined, first of all, by the spatial arrangement of different plant species - tiered . Distinguish above ground And underground tiers . Aboveground tiers reduce the competition of plants for light: the upper tiers are occupied, as a rule, by light-loving species, and the lower ones by shade-tolerant and shade-loving species. Likewise, underground tiering reduces competition for water and minerals. The layered arrangement of plants also affects the spatial arrangement of animal populations that are trophically or spatially associated with vegetation.

3. Ecological structure is determined by a certain ratio of populations of different ecological groups of organisms (their life forms). As you already remember, according to the type of nutrition, all organisms are divided into autotrophs, heterotrophs and mixotrophs. Mixotprofs - organisms capable of synthesizing organic compounds from inorganic ones and consuming ready-made organic substances (green euglena, chlamydomonas, etc.).

In turn, among heterotrophs, according to the nature of nutrition, the following groups are distinguished:

- saprotrophs - organisms that feed on the remains of other organisms or their metabolic products.

- predators - animals (sometimes plants) that catch, kill and eat other animals.

- phytophages - organisms that feed on plants.

Heterotrophic organisms that can feed on foods of different origins are called polyphages . For example, a brown bear feeds both as a predator and as a phytophage; a wide range of food for animals such as wild boar, gray rat, red cockroach and others.

III. All populations of organisms that are part of a certain biogeocenosis are interconnected. Relationships between populations of different species in a biocenosis can be divided into antagonistic, mutualistic and neutral.

For example, during the 20th century in Ukraine, the broad-toed crayfish was replaced by narrow-toed crayfish. The first of them, which dominated reservoirs at the beginning of the century, is now found only in rivers in the northern part of the country and is listed in the Red Book of Ukraine. After the mass death of the broad-clawed crayfish as a result of a viral disease (crayfish plague) in fresh water bodies, its place was taken by the narrow-clawed crayfish. This species turned out to be more resistant to the ever-increasing anthropogenic influence: it is less demanding on the purity of water, the oxygen content in it, and is more prolific.

At neutral relationships the existence of populations of two species on a common territory, each of them does not feel the direct negative or positive influence of the other. For example, predators that feed on different types of prey do not compete with each other.

At mutualistic (mutually beneficial) relationships each of the interacting species benefits. Examples of mutualism (bacterial nodules on the roots of legumes, mycorrhiza, etc.) were discussed in detail at the introductory lecture.

Consequently, complex and diverse relationships arise between populations of different species that are part of a certain biocenosis, which can be more or less close. Their combination ensures the functioning of the biocenosis as a single integral system and its self-regulation.

IV. Populations of species that make up a biocenosis are closely related not only to each other, but also to the conditions of the physical environment (that is, inanimate nature). In particular, they receive from the environment the substances necessary to ensure their vital functions and secrete the final products of metabolism there. Thus, communities of organisms form a single functional system with the physical habitat - an ecosystem.

The concept of “ecosystem” was proposed in 1935 by the English ecologist Arthur George Tansley (1871-1955). He considered ecosystems as functional units of the nature of our planet, which can cover any part of the biosphere. Ecosystem - a set of populations of organisms of various species that interact with each other and with inanimate nature in such a way that energy flows and the circulation of substances arise within the system. This ensures its functioning as a single integral multicomponent system.

In 1940, Russian ecologist Vladimir Nikolaevich Sukachev proposed the concept of “biogeocenosis.” Biogeocenosis - a certain territory with more or less homogeneous living conditions, inhabited by interconnected populations of various species, united by each other and the physical habitat by the cycle of substances and energy flows. The basis of any biogeocenosis are photosynthetic organisms.

Thus, the concepts of “ecosystem” and “biogeocoenosis” are quite close, but not identical. Biogeocenosis, in contrast to an ecosystem, is a more specific concept, since it occupies an area of terrain with homogeneous living conditions and a specific plant community.

V. Since biogeocenosis is a set of populations of living organisms that interact with each other and the physical environment, it is distinguished biotic (the totality of populations of organisms - biocenosis ) and abiotic (physical habitat conditions – biotope ) parts.

Part abiotic part includes the following components:

Inorganic substances (carbon dioxide, oxygen, water, etc.), which, due to the activity of living organisms, are included in the cycle;

Organic substances (remains of living organisms or products of their vital activity), linking together the abiotic and biotic parts of the biogeocenosis;

Climatic regime, or microclimate (average annual temperature, amount of precipitation, etc.), which determines the conditions for the existence of organisms.

The biotic part of the biogeocenosis constitute different ecological groups of organisms united by spatial and trophic connections:

- producers - populations of autotrophic organisms capable of synthesizing organic substances from inorganic ones (phototrophic or chemotrophic organisms);

-
decomposers - populations of organisms that feed on dead organic matter, decomposing it into inorganic compounds (various bacteria, fungi).

VI . Organisms in an ecosystem are connected by a commonality of energy and nutrients that are necessary to sustain life. In the overwhelming majority of cases (with the exception of some deep-sea marine communities), the main source of energy entering the biogeocenosis is sunlight. Photosynthetic organisms (green plants, cyanobacteria, some bacteria) directly use the energy of sunlight. In this case, complex organic substances are formed from carbon dioxide and water, in which part of the solar energy is accumulated in the form of chemical energy. Organic substances serve as a source of energy not only for the plant itself, but also for other organisms in the ecosystem. Plants use part of the absorbed energy to support their own vital processes, and part is stored in the form of organic compounds synthesized by them. Organisms that feed on green plants also store only part of the energy received from food, and the rest is dissipated in the form of heat and spent on vital processes. A similar thing happens when herbivorous species are eaten by predators, etc.

The release of energy contained in food occurs during the process of breathing. Respiration products - carbon dioxide, water and inorganic substances - can be reused by green plants. As a result, substances in this ecosystem undergo an endless cycle. At the same time, the energy contained in food does not cycle, but gradually turns into thermal energy and leaves the ecosystem. Therefore, a necessary condition for the existence of an ecosystem is a constant flow of energy from outside.

We can imagine a series of organisms in which individuals of one species, their remains or waste products serve as food for organisms of another. Such series of organisms are called power circuits . Each food chain consists of a certain number of links (that is, a certain number of species). Moreover, each of these species occupies a certain position, or trophic level, in the food chain. There are two types of power circuits: pasture And detrital .

At first pasture-type food chains there are producers (that is, autotrophic organisms). The trophic level of consumers (heterotrophic organisms) is determined by the number of links through which they receive energy from producers. Trophic level, or order of consumers, is usually indicated by Roman numerals.

Part of the biomass of dead producers that was not utilized by consumers (for example, leaf litter), as well as the remains or waste products of consumers themselves (for example, corpses, animal excrement) constitute the food supply of decomposers. Reducers obtain the energy they need by decomposing organic compounds into inorganic ones in several stages. However, the decomposers themselves can serve as food for consumers of the first order, who in turn can be eaten by consumers of the second order, etc. This is already a food chain detrital type , which begins not from producers, but from dead organic remains - detritus.

Since when energy is transferred from a lower trophic level to a higher one, most of it is dissipated in the form of heat, the number of links in the food chain is limited (usually does not exceed 4-6) and the circulation of energy in the biogeocenosis, unlike the circulation of substances, is impossible. For the normal functioning of biogeocenosis, a constant supply of a certain amount of energy from the outside is necessary, which compensates for its losses by living organisms. Consequently, the basis of any biogeocenosis should be autotrophic organisms capable of capturing the energy of sunlight (or the energy of the earth’s interior through substances released from them in the case of chemotrophic organisms) and converting it into the energy of chemical bonds of organic compounds synthesized by them.

In any biogeocenosis, various food chains do not exist separately from one another, but are intertwined. This happens because organisms of the same species can be links in different food chains. For example, individuals of one species of birds can feed on both herbivorous (consumers of the second order) and predatory species of insects (consumers of the third, etc. orders). Intertwined, different power chains form trophic network of biogeocenosis . Trophic networks ensure the stability of biogeocenoses, since when the number of some species decreases (or even when they completely disappear from the biogeocenosis), the species that feed on them can move to other food items, as a result of which the total productivity of the biogeocenosis remains stable.

For all food chains, there are certain ratios of consumed and stored products (that is, biomass with the energy contained in it) at each trophic level. These patterns are called rules of the ecological pyramid : at each previous trophic level, the amount of biomass and energy that is stored by organisms per unit of time is significantly greater than at the next one (on average, 5-10 times).

Graphically, this rule can be depicted as a pyramid made up of individual blocks. Each block of such a pyramid corresponds to the productivity of organisms at each of the trophic levels of the food chain. That is, the ecological pyramid is a graphic representation of the trophic structure of the food chain. There are different types of ecological pyramids, depending on what indicator is used as its basis. So, biomass pyramid displays quantitative patterns of transfer of mass of organic matter along the food chain; energy pyramid - corresponding patterns of energy transfer from one link of the power chain to the next. Developed and pyramid of numbers , displaying the number of individuals at each trophic level of the food chain.

Test work on theme "Biosphere"

Option #1

1) ecosystem 3) biosphere

2) noosphere 4) view

1) hydrosphere 3) lithosphere

1) simpler

1) animals 3) mushrooms

2) bacteria 4) plants

1) type of animal 3) kingdom

1) oxygen 3) climate

The biosphere includes:

A. plants D. bacteria

Explain why biological evolution followed chemical evolution and not vice versa.

Test work on theme "Biosphere"

Option No. 2

Part 1. Choose one correct answer.

1) creation of nature reserves

1) biosphere 3) biosphere

3) cosmic energy

4) solar energy

Part 3. Give a detailed answer to the following question.

What is the significance of the cycle of substances in nature for the existence of the biosphere? Give examples.

Test work on theme "Biosphere"

Option No. 3

Part 1. Choose one correct answer.

increased photosynthesis

gas 4) concentration

reserve 3) community

gas 3) storage

chemical 4) biological

reserves 3) reserves

Part 2. Select several correct statements

D. breathing process

Part 3. Give a detailed answer to the following question.

Name the components and boundaries of the biosphere.

Test work on theme "Biosphere"

Option No. 4

Part 1. Choose one correct answer.

A1. A set of populations of different species, interconnected by food and energy connections, as well as with factors of inanimate nature, the cycle of substances, living for a long time in a certain territory, is called:

1) ecosystem 3) biosphere

2) noosphere 4) view

A2. In the cycle of substances the greatest role is played by:

1) abiotic factors 3) living organisms

2) anthropogenic factors 4) biological rhythms

A3. The main reason for the decline in the number of species on Earth in the twentieth century is the action of the anthropogenic factor, since it:

1) weakens competition between species

2) changes their habitat

3) helps to lengthen food chains

4) affects seasonal changes in nature

A4. The youngest of all spheres of the Earth is the biosphere, since it arose only with the advent of:

1) hydrosphere 3) lithosphere

2) atmosphere 4) life on Earth

A5. The reason for the decrease in soil fertility under human influence is:

1) application of fertilizers 3) erosion, salinization

2) creation of forest belts in the steppe 4) alternation of cultivated plants

A6. Biotechnological methods of food production are more efficient because they:

1) simpler

2) allow you to obtain environmentally friendly products

3) does not require special conditions

4) does not require skilled labor

A7. An ecosystem created by man for growing crops is called:

1) biogeocenosis 3) biosphere

2) agrocenosis 4) experimental station

A8. In most ecosystems, the primary source of organic matter and energy is:

1) animals 3) mushrooms

2) bacteria 4) plants

A9. The source of energy for photosynthesis in plants is light, which is classified as a factor:

1) non-periodic 3) abiotic

2) anthropogenic 4) biotic

A10. Living organisms have repeatedly used the same chemical elements during the existence of the biosphere due to:

1) synthesis of substances by organisms 3) circulation of substances

2) the breakdown of substances by organisms 4) the constant supply of substances from Space

A11. The structural and functional unit of the biosphere is

1) type of animal 3) kingdom

2) plant department 4) biogeocenosis

A12. The reason for the negative impact of humans on the biosphere, manifested in disruption of the oxygen cycle, is:

1) creation of artificial reservoirs 3) reduction of forest area

2) land irrigation 4) drainage of swamps

A13. What function of living matter underlies its ability to accumulate chemical elements from the environment?

1) gas 3) concentration

2) redox 4) biogeochemical

A14. The following is most actively involved in the cycle of substances and energy conversion in the biosphere:

1) oxygen 3) climate

2) living matter 4) heat of the earth’s interior

Part 2. Select several correct statements.

The biosphere includes:

A. plants D. bacteria

B. bioinert substance D. biogenic substance

B. living matter E. inert matter

Part 3. Give a detailed answer to the following question.

What are the main functions of living matter in the biosphere?

Test work on theme "Biosphere"

Option No. 5

Part 1. Choose one correct answer.

A1. In preserving the diversity of plant and animal species in the biosphere, the following is of great importance:

1) creation of nature reserves

2) expansion of the area of agrocenoses

3) increasing the productivity of agrocenoses

4) pest control of agricultural plants

A2. The closed, balanced cycle of substances in the ecosystem causes:

1) self-regulation 3) ecosystem changes

2) population fluctuations 4) ecosystem stability

A3. Russian scientist V.I. Vernadsky created the doctrine of:

1) biogeocenoses 3) biorhythms

2) the leading role of living matter in the biosphere 4) photoperiodism

A4. The introduction of low-waste technologies into industrial production allows:

1) protect the biosphere from pollution

2) increase the productivity of agrocenoses

3) accelerate the circulation of substances in the biosphere

4) slow down the cycle of substances in the biosphere

A5. The coniferous forest is home to many species associated with each other and with factors of inanimate nature, which is why it is called:

1) biosphere 3) biosphere

2) biogeocenosis 4) reserve

A6. The largest role in the cycle of substances is played by

1) abiotic factors 3) anthropogenic factors

2) limiting factors 4) living matter

A7. The removal by humans of a significant amount of biomass from the ecosystem makes the cycle of substances unbalanced, which causes:

1) unstable ecosystem 3) self-regulation in the ecosystem

2) stable ecosystem 4) increasing population size

A8. The mass of living matter in the biosphere is very small, but it plays a huge role in...

1) creation of the lithosphere 3) creation of the World Ocean

2) transformation of matter and energy 4) formation of continents

A9. The negative consequences of human impact on the biosphere are manifested in:

1) change in atmospheric pressure

2) regulation of the population of game animals

3) reduction of biodiversity

4) creation of new varieties of plants and animal breeds

A10. Changes by organisms in the process of vital activity of the habitat in an ecosystem are the cause of:

1) circulation of substances 3) the emergence of adaptations in organisms

2) changes in ecosystems 4) emergence of new species

A11. Industrial wastes - salts of heavy metals: lead, cadmium - cause poisoning in people, the birth of deformities, entering their body:

1) during the process of reproduction 3) with inhaled air

2) through food chains 4) with wastewater

A12. The name "Biosphere" was first given:

1) By Linnaeus 3) V.I. Vernadsky

2) J.B. Lamarck 4) V.N. Sukachev

A13. The biosphere exists mainly due to:

1) cosmic energy and intraplanetary thermal energy

2) intraplanetary thermal energy

3) cosmic energy

4) solar energy

A14. The upper boundary of the biosphere is limited by:

1) bird flight altitude 3) ozone layer

2) spore detection height 4) has no upper limit

Part 2. Select several correct statements

The functions of living matter in the biosphere include:

A. cumulative D. concentration

B. redox D. gas

B. conductive E. oxidative

Part 3. Give a detailed answer to the following question.

What are the reasons for the stability of the biosphere?

Test work on theme "Biosphere"

Option No. 6

Part 1. Choose one correct answer.

A1. The process of periodic decrease in population size under the influence of environmental factors to a certain limit and its subsequent increase is called:

biological rhythm 3) self-regulation

circulation of substances 4) migration of atoms

A2. The process of destruction of organic substances by decomposers to inorganic ones and their return to the environment is an important link in:

metabolism 3) circulation of substances

self-regulation 4) seasonal changes in the life of organisms

A3. Mass cutting down of dominant, environment-forming tree species in a forest can lead to:

strengthening the circulation of substances 3) lengthening food chains

the emergence of food chains 4) ecosystem changes

A4. Acid rain, which is formed as a result of atmospheric pollution with nitrogen and sulfur oxides, leads to:

improvement of mineral nutrition of plants

loss of forests in several regions of the globe

improving water metabolism in plants

increased photosynthesis

A5. Photosynthesis and respiration are functions of living matter:

redox 3) biogeochemical

gas 4) concentration

A6. In many countries around the world, “green” parties have been created whose actions are aimed at:

protection of the biosphere 3) protection of human rights to clean air

refusal to use any technology 4) suspension of the development of the biosphere

A7. Ecosystems in which the shooting of rare species of animals and the collection of plants are prohibited are called:

reserve 3) community

agroecosystem 4) forest park

A8. Great species diversity, self-regulation, balanced circulation of substances are signs of:

agroecosystem 3) unstable ecosystem

sustainable ecosystem 4) ecosystem development

A9. The ability of organisms to convert some substances into others and form salts and oxides is the function of living matter:

gas 3) storage

2) concentration 4) redox

A10. The biosphere as a global ecosystem consists of:

biotic and chemical components

biotic and dead components

living and chemical components

biotic and abiotic components

A11. The living matter of the biosphere is formed by a combination of individuals of all species:

animals, including humans 3) plants and humans

plants and animals 4) living organisms inhabiting the planet

A12. Biogenic migration of atoms is called... the cycle:

biochemical 3) biogeochemical

chemical 4) biological

A13. All species of plants and animals and their natural environment are protected in:

reserves 3) reserves

biogeocenoses 4) natural parks

A14. Despite the constant use by plants of inorganic substances absorbed from the soil, their supply in the soil does not dry out, as the following occurs:

metabolism 3) circulation of substances

change of biogeocenoses 4) self-regulation

Part 2. Select several correct statements

The gas function of living matter includes the following processes:

A. return of molecular nitrogen to the atmosphere by bacteria

B. assimilation of atmospheric molecular nitrogen by nodule bacteria

B. the ability to accumulate a certain substance in the cells of horsetails and sedges

D. breathing process

D. accumulation of iodine in the cells of kelp seaweed

E. accumulation of chemicals in the cells of organisms

Part 3. Give a detailed answer to the following question.

Explain the main difference between the ideas of A.I. Oparin and J. Haldane about the origin of life.

Answer key to tests on the biosphere.

question number

option

1,4

2,5

3,6

A10

A11

A12

A13

A14

Task 2

BVDE

ABG

EVALUATION CRITERIA:

Part 1. For each correct answer 1 point (total 14 points)

Part 2. For each correct answer 0.5 points (total 3 points)

Part 1. 1 – 3 points

Maximum points - 20

SCALE FOR CONVERTING POINTS TO GRADES

"2"

"3"

"4"

"5"

0 – 10b.

11 – 14b.

15 – 17b.

18 – 20b.

In nature, each existing species is a complex complex or even a system of intraspecific groups, which include individuals with specific structural features, physiology and behavior. This intraspecific association of individuals is population.

The word “population” comes from the Latin “populus” - people, population. Hence, population- a collection of individuals of the same species living in a certain territory, i.e. those that only interbreed with each other. The term “population” is currently used in the narrow sense of the word, when talking about a specific intraspecific group inhabiting a certain biogeocenosis, and in a broad, general sense - to designate isolated groups of a species, regardless of what territory it occupies and what genetic information it carries.

Members of the same population have no less impact on each other than physical environmental factors or other species of organisms living together. In populations, all forms of connections characteristic of interspecific relationships are manifested to one degree or another, but most clearly expressed mutualistic(mutually beneficial) and competitive. Populations can be monolithic or consist of subpopulation-level groups - families, clans, herds, packs and so on. The combination of organisms of the same species into a population creates qualitatively new properties. Compared to the lifespan of an individual organism, a population can exist for a very long time.

At the same time, a population is similar to an organism as a biosystem, since it has a certain structure, integrity, a genetic program for self-reproduction, and the ability to reproduce and adapt. The interaction of people with species of organisms found in the environment, in the natural environment or under human economic control, is usually mediated through populations. It is important that many patterns of population ecology also apply to human populations.

Population is the genetic unit of a species, changes in which are carried out by the evolution of the species. As a group of cohabiting individuals of the same species, a population acts as the first supraorganismal biological macrosystem. A population's adaptive capabilities are significantly higher than those of its constituent individuals. A population as a biological unit has certain structure and functions.

Population structure characterized by its constituent individuals and their distribution in space.

Population functions similar to the functions of other biological systems. They are characterized by growth, development, and the ability to maintain existence in constantly changing conditions, i.e. populations have specific genetic and environmental characteristics.

Populations have laws that allow limited environmental resources to be used in this way to ensure the preservation of offspring. Populations of many species have properties that allow them to regulate their numbers. Maintaining optimal numbers under given conditions is called population homeostasis.

Thus, populations, as group associations, have a number of specific properties that are not inherent in each individual individual. Main characteristics of populations: number, density, birth rate, death rate, growth rate.

A population is characterized by a certain organization. The distribution of individuals across the territory, the ratio of groups by sex, age, morphological, physiological, behavioral and genetic characteristics reflect population structure. It is formed, on the one hand, on the basis of the general biological properties of the species, and on the other, under the influence of abiotic environmental factors and populations of other species. The structure of populations therefore has an adaptive character.

The adaptive capabilities of a species as a whole as a system of populations are much broader than the adaptive characteristics of each individual individual.

Population structure of the species

The space or habitat occupied by a population may vary between species and within the same species. The size of a population's range is determined to a large extent by the mobility of individuals or the radius of individual activity. If the radius of individual activity is small, the size of the population range is usually also small. Depending on the size of the occupied territory, we can distinguish three types of populations: elementary, environmental and geographical (Fig. 1).

Rice. 1. Spatial division of populations: 1 - species range; 2-4 - geographical, ecological and elementary populations, respectively

There are sex, age, genetic, spatial and ecological structures of populations.

Sex structure of the population represents the ratio of individuals of different sexes in it.

Age structure of the population- the ratio in the population of individuals of different ages, representing one or different offspring of one or several generations.

Genetic structure of the population is determined by the variability and diversity of genotypes, the frequencies of variations of individual genes - alleles, as well as the division of the population into groups of genetically similar individuals, between which, when crossed, there is a constant exchange of alleles.

Spatial structure of the population - the nature of the placement and distribution of individual members of the population and their groups in the area. The spatial structure of populations differs markedly between sedentary and nomadic or migrating animals.

Ecological population structure represents the division of any population into groups of individuals that interact differently with environmental factors.

Each species, occupying a specific territory ( range), represented on it by a system of populations. The more complex the territory occupied by a species is, the greater the opportunities for the isolation of individual populations. However, to a lesser extent, the population structure of a species is determined by its biological characteristics, such as the mobility of its constituent individuals, the degree of their attachment to the territory, and the ability to overcome natural barriers.

Isolation of populations

If the members of a species are constantly intermingled and intermingled over large areas, the species is characterized by a small number of large populations. With poorly developed ability to move, many small populations are formed within the species, reflecting the mosaic nature of the landscape. In plants and sedentary animals, the number of populations is directly dependent on the degree of heterogeneity of the environment.

The degree of isolation of neighboring populations of the species varies. In some cases, they are sharply separated by territory unsuitable for habitation and are clearly localized in space, for example, populations of perch and tench in lakes isolated from each other.

The opposite option is the complete settlement of vast territories by the species. Within the same species there can be populations with both clearly distinguishable and blurred boundaries, and within the species, populations can be represented by groups of different sizes.

Connections between populations support the species as a whole. Too long and complete isolation of populations can lead to the formation of new species.

Differences between individual populations are expressed to varying degrees. They can affect not only their group characteristics, but also the qualitative features of the physiology, morphology and behavior of individual individuals. These differences are created mainly under the influence of natural selection, which adapts each population to the specific conditions of its existence.

Classification and structure of populations

A mandatory feature of a population is its ability to exist independently in a given territory for an indefinitely long time due to reproduction, and not the influx of individuals from the outside. Temporary settlements of different scales do not belong to the category of populations, but are considered intra-population units. From these positions, the species is represented not by hierarchical subordination, but by a spatial system of neighboring populations of different scales and with varying degrees of connections and isolation between them.

Populations can be classified according to their spatial and age structure, density, kinetics, constancy or change of habitats and other environmental criteria.

The territorial boundaries of populations of different species do not coincide. The diversity of natural populations is also expressed in the variety of types of their internal structure.

The main indicators of population structure are the number, distribution of organisms in space and the ratio of individuals of different qualities.

The individual traits of each organism depend on the characteristics of its hereditary program (genotype) and how this program is implemented during ontogenesis. Each individual has a certain size, sex, distinctive morphological features, behavioral characteristics, its own limits of endurance and adaptability to environmental changes. The distribution of these characteristics in a population also characterizes its structure.

The population structure is not stable. The growth and development of organisms, the birth of new ones, death from various causes, changes in environmental conditions, an increase or decrease in the number of enemies - all this leads to changes in various relationships within the population. The direction of its further changes largely depends on the structure of the population in a given period of time.

Sexual structure of populations

The genetic mechanism for sex determination ensures that the offspring are separated by sex in a 1:1 ratio, the so-called sex ratio. But it does not follow from this that the same ratio is characteristic of the population as a whole. Sex-linked traits often determine significant differences in the physiology, ecology and behavior of females and males. Due to the different viability of male and female organisms, this primary ratio often differs from the secondary and especially from the tertiary - characteristic of adult individuals. Thus, in humans, the secondary sex ratio is 100 girls to 106 boys; by the age of 16-18 this ratio levels out due to increased male mortality and by the age of 50 it is 85 men per 100 women, and by the age of 80 it is 50 men per 100 women.

The sex ratio in a population is established not only according to genetic laws, but also to a certain extent under the influence of the environment.

Age structure of populations

Fertility and mortality, population dynamics are directly related to the age structure of the population. The population consists of individuals of different ages and sexes. Each species, and sometimes each population within a species, has its own age group ratios. In relation to the population it is usually distinguished three ecological ages: pre-reproductive, reproductive and post-reproductive.

With age, an individual's requirements for the environment and resistance to its individual factors naturally and very significantly change. At different stages of ontogenesis, changes in habitats, changes in the type of food, the nature of movement, and the general activity of organisms can occur.

Age differences in a population significantly increase its ecological heterogeneity and, consequently, its resistance to the environment. The likelihood increases that in the event of strong deviations of conditions from the norm, at least some viable individuals will remain in the population, and it will be able to continue its existence.

The age structure of populations is adaptive in nature. It is formed on the basis of the biological properties of the species, but always also reflects the strength of the influence of environmental factors.

Age structure of plant populations

In plants, the age structure of the cenopopulation, i.e. population of a particular phytocenosis is determined by the ratio of age groups. The absolute, or calendar, age of a plant and its age state are not identical concepts. Plants of the same age can be in different age states. The age-related, or ontogenetic state of an individual is the stage of its ontogenesis, at which it is characterized by certain relationships with the environment.

The age structure of the coenopopulation is largely determined by the biological characteristics of the species: the frequency of fruiting, the number of produced seeds and vegetative rudiments, the ability of vegetative rudiments to rejuvenate, the rate of transition of individuals from one age state to another, the ability to form clones, etc. The manifestation of all these biological characteristics, in turn turn depends on environmental conditions. The course of ontogenesis also changes, which can occur in one species in many ways.

Different plant sizes reflect different vitality individuals within each age group. The vitality of an individual is manifested in the power of its vegetative and generative organs, which corresponds to the amount of accumulated energy, and in resistance to adverse influences, which is determined by the ability to regenerate. The vitality of each individual changes in ontogenesis along a single-peak curve, increasing on the ascending branch of ontogenesis and decreasing on the descending branch.

Many meadow, forest, steppe species, when grown in nurseries or crops, i.e. on the best agrotechnical background, they shorten their ontogeny.

The ability to change the path of ontogenesis ensures adaptation to changing environmental conditions and expands the ecological niche of the species.

Age structure of populations in animals

Depending on the characteristics of reproduction, members of a population may belong to the same generation or to different ones. In the first case, all individuals are close in age and approximately simultaneously go through the next stages of the life cycle. The timing of reproduction and the passage of individual age stages is usually confined to a certain season of the year. The size of such populations is, as a rule, unstable: strong deviations of conditions from the optimum at any stage of the life cycle immediately affect the entire population, causing significant mortality.

In species with single reproduction and short life cycles, several generations occur throughout the year.

When humans exploit natural animal populations, taking into account their age structure is of utmost importance. In species with large annual recruitment, larger portions of the population can be removed without the threat of depleting its numbers. For example, in pink salmon that mature in the second year of life, it is possible to catch up to 50-60% of spawning individuals without the threat of a further decline in population size. For chum salmon, which mature later and have a more complex age structure, removal rates from a mature stock should be lower.

Analysis of the age structure helps to predict the population size over the life of a number of next generations.

The space occupied by a population provides it with the means to live. Each territory can support only a certain number of individuals. Naturally, the complete use of available resources depends not only on the total population size, but also on the distribution of individuals in space. This is clearly manifested in plants, the feeding area of which cannot be less than a certain limiting value.

In nature, an almost uniform, ordered distribution of individuals within an occupied territory is rarely encountered. However, most often the members of a population are distributed unevenly in space.

In each specific case, the type of distribution in the occupied space turns out to be adaptive, i.e. allows optimal use of available resources. Plants in a cenopopulation are most often distributed extremely unevenly. Often the denser center of the aggregation is surrounded by individuals located less densely.

The spatial heterogeneity of the cenopopulation is associated with the nature of the development of clusters over time.

In animals, due to their mobility, the ways of regulating territorial relations are more diverse compared to plants.

In higher animals, intrapopulation distribution is regulated by a system of instincts. They are characterized by special territorial behavior - a reaction to the location of other members of the population. However, a sedentary lifestyle poses the risk of rapid depletion of resources if population densities become too high. The total area occupied by the population is divided into separate individual or group areas, thereby achieving the orderly use of food supplies, natural shelters, breeding sites, etc.

Despite the territorial isolation of members of the population, communication is maintained between them using a system of various signals and direct contacts at the borders of their possessions.

“Securing an area” is achieved in different ways: 1) protecting the boundaries of the occupied space and direct aggression towards a stranger; 2) special ritual behavior demonstrating a threat; 3) a system of special signals and marks indicating the occupancy of the territory.

The usual reaction to territorial marks—avoidance—is inherited in animals. The biological benefit of this type of behavior is obvious. If the mastery of a territory were decided only by the outcome of a physical struggle, the appearance of each stronger alien would threaten the owner with the loss of the site and exclusion from reproduction.

Partial overlapping of individual territories serves as a way to maintain contacts between members of the population. Neighboring individuals often maintain a stable, mutually beneficial system of connections: mutual warning of danger, joint protection from enemies. Normal behavior of animals includes an active search for contacts with members of their own species, which often intensifies during periods of population decline.

Some species form widely wandering groups that are not tied to a specific territory. This is the behavior of many fish species during feeding migrations.

There are no absolute distinctions between different ways of using the territory. The spatial structure of the population is very dynamic. It is subject to seasonal and other adaptive changes in accordance with place and time.

The patterns of animal behavior constitute the subject of a special science - ethology. The system of relationships between members of one population is therefore called the ethological, or behavioral structure of the population.

The behavior of animals in relation to other members of the population depends, first of all, on whether a solitary or group lifestyle is characteristic of the species.

A solitary lifestyle, in which individuals of a population are independent and isolated from each other, is characteristic of many species, but only at certain stages of the life cycle. Completely solitary existence of organisms does not occur in nature, since in this case it would be impossible to carry out their main vital function - reproduction.

With a family lifestyle, the bonds between parents and their offspring also strengthen. The simplest type of such connection is the care of one of the parents for laid eggs: protection of the clutch, incubation, additional aeration, etc. With a family lifestyle, the territorial behavior of animals is most pronounced: various signals, markings, ritual forms of threat and direct aggression ensure ownership of an area sufficient for feeding offspring.

Larger animal associations - flocks, herds And colonies. Their formation is based on the further complication of behavioral connections in populations.

Life in a group, through the nervous and hormonal systems, affects the course of many physiological processes in the animal’s body. In isolated individuals, the level of metabolism changes noticeably, reserve substances are consumed faster, a number of instincts do not manifest themselves, and overall vitality deteriorates.

Positive group effect manifests itself only up to a certain optimal level of population density. If there are too many animals, this threatens everyone with a lack of environmental resources. Then other mechanisms come into play, leading to a decrease in the number of individuals in the group through its division, dispersal, or a drop in the birth rate.