Food or trophic chain call the relationship between different groups of organisms (plants, fungi, animals and microbes), in which energy is transported as a result of the consumption of some individuals by others. Energy transfer is the basis for the normal functioning of an ecosystem. Surely these concepts are familiar to you from the 9th grade of school from the general biology course.
Individuals of the next link eat the organisms of the previous link, and this is how matter and energy are transported along the chain. This sequence of processes underlies the living cycle of substances in nature. It is worth saying that a huge part of the potential energy (approximately 85%) is lost when transferred from one link to another, it is dissipated, that is, dissipated in the form of heat. This factor is limiting in relation to the length of food chains, which in nature usually have 4-5 links.
Types of food relationships
Within ecosystems, organic matter is produced by autotrophs (producers). Plants, in turn, are eaten by herbivorous animals (first-order consumers), which are then eaten by carnivorous animals (second-order consumers). This 3-link food chain is an example of a proper food chain.
Pasture chains
Trophic chains begin with auto- or chemotrophs (producers) and include heterotrophs in the form of consumers of various orders. Such food chains are widespread in land and marine ecosystems. They can be drawn and compiled in the form of a diagram:
Producers -> Consumers of the 1st order -> Consumers of the 1st order -> Consumers of the 3rd order.
A typical example is the food chain of a meadow (it can be a forest zone or a desert, in this case only the biological species of various participants in the food chain and the branching of the network of food interactions will differ).
So, with the help of the energy of the Sun, a flower produces nutrients for itself, that is, it is a producer and the first link in the chain. A butterfly that feeds on the nectar of this flower is a consumer of the first order and the second link. The frog, which also lives in the meadow and is an insectivorous animal, eats the butterfly - the third link in the chain, a consumer of the second order. The frog is swallowed by a snake - the fourth link and a consumer of the third order, the snake is eaten by a hawk - a consumer of the fourth order and the fifth, as a rule, the last link in the food chain. A person can also be present in this chain as a consumer.
In the waters of the World Ocean, autotrophs, represented by unicellular algae, can exist only as long as sunlight can penetrate through the water column. This is a depth of 150-200 meters. Heterotrophs can also live in deeper layers, rising to the surface at night to feed with algae, and in the morning again going to the usual depth, making vertical migrations of up to 1 kilometer per day. In turn, heterotrophs, which are consumers of subsequent orders and live even deeper, rise in the morning to the level of habitat of consumers of the first order in order to feed on them.
Thus, we see that in deep bodies of water, usually seas and oceans, there is such a thing as a “food ladder.” Its meaning is that organic substances that are created by algae in the surface layers of the earth are transported along the food chain to the very bottom. Taking this fact into account, the opinion of some ecologists that the entire reservoir can be considered a single biogeocenosis can be considered justified.
Detrital trophic relationships
To understand what the detrital food chain is, you need to start with the very concept of “detritus.” Detritus is a collection of remains of dead plants, corpses and end products of animal metabolism.
Detrital chains are typical for communities of inland waters, deep lake bottoms, and oceans, many of whose representatives feed on detritus formed by the remains of dead organisms from the upper layers or accidentally introduced into the reservoir from ecological systems located on land, in the form of, for example , leaf litter.
Bottom ecological systems of oceans and seas, where there are no producers due to the lack of sunlight, can exist only due to detritus, the total mass of which in the World Ocean in a calendar year can reach hundreds of millions of tons.
Detritus chains are also common in forests, where a considerable part of the annual increase in biomass of producers cannot be consumed directly by the first link of consumers. Therefore, it dies, forming litter, which, in turn, is decomposed by saprotrophs and then mineralized by decomposers. Fungi play an important role in the formation of detritus in forest communities.
Heterotrophs that feed directly on detritus are detritivores. In terrestrial ecological systems, detritivores include some species of arthropods, in particular insects, as well as annelids. Large detritivores among birds (vultures, crows) and mammals (hyenas) are usually called scavengers.
In ecological systems of waters, the bulk of detritivores are aquatic insects and their larvae, as well as some representatives of crustaceans. Detritivores can serve as food for larger heterotrophs, which, in turn, can also later become food for consumers of higher orders.
The links in the food chain are otherwise called trophic levels. By definition, this is a group of organisms that occupies a specific place in the food chain and provides a source of energy for each of the subsequent levels - food.
Organisms I trophic level in pasture food chains there are primary producers, autotrophs, that is, plants, and chemotrophs - bacteria that use the energy of chemical reactions to synthesize organic substances. In detrital systems, there are no autotrophs, and the first trophic level of the detrital trophic chain forms detritus itself.
Last, V trophic level represented by organisms that consume dead organic matter and final decay products. These organisms are called destructors or decomposers. Decomposers are mainly represented by invertebrate animals, which are necro-, sapro- and coprophages, using residues, waste and dead organic matter for food. Also included in this group are saprophagous plants that decompose leaf litter.
Also included in the level of destructors are heterotrophic microorganisms that are capable of converting organic substances into inorganic (mineral) substances, forming final products - carbon dioxide and water, which return to the ecological system and re-enter the natural cycle of substances.
The importance of food relationships
Introduction
1. Food chains and trophic levels
2. Food webs
3. Freshwater food connections
4. Forest food connections
5. Energy losses in power circuits
6. Ecological pyramids
6.1 Pyramids of numbers
6.2 Biomass pyramids
Conclusion
Bibliography
Introduction
Organisms in nature are connected by a commonality of energy and nutrients. The entire ecosystem can be likened to a single mechanism that consumes energy and nutrients to do work. Nutrients initially originate from the abiotic component of the system, to which they are ultimately returned either as waste products or after the death and destruction of organisms.
Within an ecosystem, energy-containing organic substances are created by autotrophic organisms and serve as food (a source of matter and energy) for heterotrophs. A typical example: an animal eats plants. This animal, in turn, can be eaten by another animal, and in this way energy can be transferred through a number of organisms - each subsequent one feeds on the previous one, supplying it with raw materials and energy. This sequence is called a food chain, and each link is called a trophic level.
The purpose of the essay is to characterize food connections in nature.
1. Food chains and trophic levels
Biogeocenoses are very complex. They always contain many parallel and complexly intertwined food chains, and the total number of species is often measured in hundreds and even thousands. Almost always, different species feed on several different objects and themselves serve as food for several members of the ecosystem. The result is a complex network of food connections.
Each link in the food chain is called a trophic level. The first trophic level is occupied by autotrophs, or the so-called primary producers. Organisms of the second trophic level are called primary consumers, the third - secondary consumers, etc. There are usually four or five trophic levels and rarely more than six.
The primary producers are autotrophic organisms, mainly green plants. Some prokaryotes, namely blue-green algae and a few species of bacteria, also photosynthesize, but their contribution is relatively small. Photosynthetics convert solar energy (light energy) into chemical energy contained in organic molecules from which tissues are built. Chemosynthetic bacteria, which extract energy from inorganic compounds, also make a small contribution to the production of organic matter.
In aquatic ecosystems, the main producers are algae - often small single-celled organisms that make up the phytoplankton of the surface layers of oceans and lakes. On land, most of the primary production is supplied by more highly organized forms related to gymnosperms and angiosperms. They form forests and meadows.
Primary consumers feed on primary producers, i.e. they are herbivores. On land, typical herbivores include many insects, reptiles, birds and mammals. The most important groups of herbivorous mammals are rodents and ungulates. The latter include grazing animals such as horses, sheep, and cattle, which are adapted to running on their toes.
In aquatic ecosystems (freshwater and marine), herbivorous forms are usually represented by mollusks and small crustaceans. Most of these organisms—cladocerans, copepods, crab larvae, barnacles, and bivalves (such as mussels and oysters)—feed by filtering tiny primary producers from the water. Together with protozoa, many of them form the bulk of the zooplankton that feed on phytoplankton. Life in oceans and lakes depends almost entirely on plankton, since almost all food chains begin with it.
Plant material (e.g. nectar) → fly → spider →
→ shrew → owl
Rosebush sap → aphid → ladybug → spider → insectivorous bird → bird of prey
There are two main types of food chains - grazing and detrital. Above were examples of pasture chains in which the first trophic level is occupied by green plants, the second by pasture animals and the third by predators. The bodies of dead plants and animals still contain energy and “building material,” as well as intravital excretions, such as urine and feces. These organic materials are decomposed by microorganisms, namely fungi and bacteria, living as saprophytes on organic residues. Such organisms are called decomposers. They release digestive enzymes onto dead bodies or waste products and absorb the products of their digestion. The rate of decomposition may vary. Organic matter from urine, feces and animal carcasses is consumed within weeks, while fallen trees and branches can take many years to decompose. A very significant role in the decomposition of wood (and other plant debris) is played by fungi, which secrete the enzyme cellulose, which softens the wood, and this allows small animals to penetrate and absorb the softened material.
Pieces of partially decomposed material are called detritus, and many small animals (detritivores) feed on them, speeding up the decomposition process. Since both true decomposers (fungi and bacteria) and detritivores (animals) are involved in this process, both are sometimes called decomposers, although in reality this term refers only to saprophytic organisms.
Larger organisms can, in turn, feed on detritivores, and then a different type of food chain is created - a chain, a chain starting with detritus:
Detritus → detritivore → predator
Detritivores of forest and coastal communities include earthworm, woodlice, carrion fly larva (forest), polychaete, scarlet fly, holothurian (coastal zone).
Here are two typical detrital food chains in our forests:
Leaf litter → Earthworm → Blackbird → Sparrowhawk
Dead animal → Carrion fly larvae → Grass frog → Common grass snake
Some typical detritivores are earthworms, woodlice, bipeds and smaller ones (<0,5 мм) животные, такие, как клещи, ногохвостки, нематоды и черви-энхитреиды.
2. Food webs
In food chain diagrams, each organism is represented as feeding on other organisms of one type. However, actual food relationships in an ecosystem are much more complex, since an animal may feed on different types of organisms from the same food chain or even from different food chains. This is especially true for predators of the upper trophic levels. Some animals eat both other animals and plants; they are called omnivores (this is the case, in particular, with humans). In reality, food chains are intertwined in such a way that a food (trophic) web is formed. A food web diagram can only show a few of the many possible connections, and it usually includes only one or two predators from each of the upper trophic levels. Such diagrams illustrate nutritional relationships between organisms in an ecosystem and provide the basis for quantitative studies of ecological pyramids and ecosystem productivity.
3. Freshwater food connections
The food chains of a fresh water body consist of several successive links. For example, protozoa, which are eaten by small crustaceans, feed on plant debris and the bacteria that develop on them. The crustaceans, in turn, serve as food for fish, and the latter can be eaten by predatory fish. Almost all species do not feed on one type of food, but use different food objects. Food chains are intricately intertwined. An important general conclusion follows from this: if any member of the biogeocenosis falls out, then the system is not disrupted, since other food sources are used. The greater the species diversity, the more stable the system.
The primary source of energy in aquatic biogeocenosis, as in most ecological systems, is sunlight, thanks to which plants synthesize organic matter. Obviously, the biomass of all animals existing in a reservoir completely depends on the biological productivity of plants.
Question 28. Food chain. Types of food chains.
FOOD CHAIN(trophic chain, food chain), the interconnection of organisms through food-consumer relationships (some serve as food for others). In this case, a transformation of matter and energy occurs from producers(primary producers) through consumers(consumers) to decomposers(converters of dead organic matter into inorganic substances assimilated by producers). There are 2 types of food chains - pasture and detritus. The pasture chain begins with green plants, goes to grazing herbivorous animals (consumers of the 1st order) and then to the predators that prey on these animals (depending on the place in the chain - consumers of the 2nd and subsequent orders). The detrital chain begins with detritus (a product of the breakdown of organic matter), goes to microorganisms that feed on it, and then to detritivores (animals and microorganisms involved in the process of decomposition of dying organic matter).
An example of a pasture chain is its multi-channel model in the African savanna. Primary producers are grass and trees, 1st order consumers are herbivorous insects and herbivores (ungulates, elephants, rhinoceroses, etc.), 2nd order are predatory insects, 3rd order are carnivorous reptiles (snakes, etc.), 4th – predatory mammals and birds of prey. In turn, detritivores (scarab beetles, hyenas, jackals, vultures, etc.) at each stage of the grazing chain destroy the carcasses of dead animals and the food remains of predators. The number of individuals included in the food chain in each of its links consistently decreases (the rule of the ecological pyramid), i.e., the number of victims each time significantly exceeds the number of their consumers. Food chains are not isolated from one another, but are intertwined with each other to form food webs.
Question 29. What are ecological pyramids used for? Name them.
Ecological pyramid- graphic images of the relationship between producers and consumers of all levels (herbivores, predators, species that feed on other predators) in the ecosystem.
The American zoologist Charles Elton suggested schematically depicting these relationships in 1927.
In a schematic representation, each level is shown as a rectangle, the length or area of which corresponds to the numerical values of a link in the food chain (Elton’s pyramid), their mass or energy. Rectangles arranged in a certain sequence create pyramids of various shapes.
The base of the pyramid is the first trophic level - the level of producers; subsequent floors of the pyramid are formed by the next levels of the food chain - consumers of various orders. The height of all blocks in the pyramid is the same, and the length is proportional to the number, biomass or energy at the corresponding level.
Ecological pyramids are distinguished depending on the indicators on the basis of which the pyramid is built. At the same time, the basic rule has been established for all pyramids, according to which in any ecosystem there are more plants than animals, herbivores than carnivores, insects than birds.
Based on the rule of the ecological pyramid, it is possible to determine or calculate the quantitative ratios of different species of plants and animals in natural and artificially created ecological systems. For example, 1 kg of mass of a sea animal (seal, dolphin) requires 10 kg of eaten fish, and these 10 kg already need 100 kg of their food - aquatic invertebrates, which, in turn, need to eat 1000 kg of algae and bacteria to form such a mass. In this case, the ecological pyramid will be sustainable.
However, as you know, there are exceptions to every rule, which will be considered in each type of ecological pyramid.
The first ecological schemes in the form of pyramids were built in the twenties of the 20th century. Charles Elton. They were based on field observations of a number of animals of different size classes. Elton did not include primary producers and did not make any distinction between detritivores and decomposers. However, he noted that predators are usually larger than their prey, and realized that this ratio is extremely specific only to certain size classes of animals. In the forties, the American ecologist Raymond Lindeman applied Elton's idea to trophic levels, abstracting from the specific organisms that comprise them. However, while it is easy to distribute animals into size classes, it is much more difficult to determine which trophic level they belong to. In any case, this can only be done in a very simplified and generalized manner. Nutritional relationships and the efficiency of energy transfer in the biotic component of an ecosystem are traditionally depicted in the form of stepped pyramids. This provides a clear basis for comparing: 1) different ecosystems; 2) seasonal states of the same ecosystem; 3) different phases of ecosystem change. There are three types of pyramids: 1) pyramids of numbers, based on counting organisms at each trophic level; 2) biomass pyramids, which use the total mass (usually dry) of organisms at each trophic level; 3) energy pyramids, taking into account the energy intensity of organisms at each trophic level.
Types of ecological pyramids
pyramids of numbers- at each level the number of individual organisms is plotted
The pyramid of numbers displays a clear pattern discovered by Elton: the number of individuals making up a sequential series of links from producers to consumers is steadily decreasing (Fig. 3).
For example, to feed one wolf, he needs at least several hares for him to hunt; To feed these hares, you need a fairly large variety of plants. In this case, the pyramid will look like a triangle with a wide base tapering upward.
However, this form of a pyramid of numbers is not typical for all ecosystems. Sometimes they can be reversed, or upside down. This applies to forest food chains, where trees serve as producers and insects serve as primary consumers. In this case, the level of primary consumers is numerically richer than the level of producers (a large number of insects feed on one tree), therefore the pyramids of numbers are the least informative and least indicative, i.e. the number of organisms of the same trophic level largely depends on their size.
biomass pyramids- characterizes the total dry or wet mass of organisms at a given trophic level, for example, in units of mass per unit area - g/m2, kg/ha, t/km2 or per volume - g/m3 (Fig. 4)
Usually in terrestrial biocenoses the total mass of producers is greater than each subsequent link. In turn, the total mass of first-order consumers is greater than that of second-order consumers, etc.
In this case (if the organisms do not differ too much in size) the pyramid will also have the appearance of a triangle with a wide base tapering upward. However, there are significant exceptions to this rule. For example, in the seas, the biomass of herbivorous zooplankton is significantly (sometimes 2-3 times) greater than the biomass of phytoplankton, represented mainly by unicellular algae. This is explained by the fact that algae are very quickly eaten by zooplankton, but they are protected from being completely eaten away by the very high rate of division of their cells.
In general, terrestrial biogeocenoses, where producers are large and live relatively long, are characterized by relatively stable pyramids with a wide base. In aquatic ecosystems, where producers are small in size and have short life cycles, the pyramid of biomass can be inverted or inverted (with the tip pointing down). Thus, in lakes and seas, the mass of plants exceeds the mass of consumers only during the flowering period (spring), and during the rest of the year the opposite situation can occur.
Pyramids of numbers and biomass reflect the statics of the system, that is, they characterize the number or biomass of organisms in a certain period of time. They do not provide complete information about the trophic structure of an ecosystem, although they allow solving a number of practical problems, especially related to maintaining the sustainability of ecosystems.
The pyramid of numbers allows, for example, to calculate the permissible amount of fish catch or shooting of animals during the hunting season without consequences for their normal reproduction.
energy pyramids- shows the amount of energy flow or productivity at successive levels (Fig. 5).
In contrast to the pyramids of numbers and biomass, which reflect the statics of the system (the number of organisms at a given moment), the pyramid of energy, reflecting the picture of the speed of passage of food mass (amount of energy) through each trophic level of the food chain, gives the most complete picture of the functional organization of communities.
The shape of this pyramid is not affected by changes in the size and metabolic rate of individuals, and if all energy sources are taken into account, the pyramid will always have a typical appearance with a wide base and a tapering apex. When constructing a pyramid of energy, a rectangle is often added to its base to show the influx of solar energy.
In 1942, the American ecologist R. Lindeman formulated the law of the energy pyramid (the law of 10 percent), according to which, on average, about 10% of the energy received at the previous level of the ecological pyramid passes from one trophic level through food chains to another trophic level. The rest of the energy is lost in the form of thermal radiation, movement, etc. As a result of metabolic processes, organisms lose about 90% of all energy in each link of the food chain, which is spent on maintaining their vital functions.
If a hare ate 10 kg of plant matter, then its own weight may increase by 1 kg. A fox or wolf, eating 1 kg of hare meat, increases its mass by only 100 g. In woody plants, this proportion is much lower due to the fact that wood is poorly absorbed by organisms. For grasses and seaweeds, this value is much greater, since they do not have difficult-to-digest tissues. However, the general pattern of the process of energy transfer remains: much less energy passes through the upper trophic levels than through the lower ones.
Target: expand knowledge about biotic environmental factors.
Equipment: herbarium plants, stuffed chordates (fish, amphibians, reptiles, birds, mammals), insect collections, wet preparations of animals, illustrations of various plants and animals.
Progress:
1. Use the equipment and make two power circuits. Remember that the chain always starts with a producer and ends with a reducer.
Plants → insects→lizard → bacteria
Plants → grasshopper→ frog → bacteria
Remember your observations in nature and make two food chains. Label producers, consumers (1st and 2nd orders), decomposers.
Violet → Springtails→predatory mites→predatory centipedes→ bacteria
Producer - consumer1 - consumer2 - consumer2 - decomposer
Cabbage→ slug→ frog →bacteria
Producer – consumer1 - consumer2 - decomposer
What is a food chain and what underlies it? What determines the stability of a biocenosis? State your conclusion.
Conclusion:
Food (trophic) chain- a series of species of plants, animals, fungi and microorganisms that are connected to each other by the relationship: food - consumer (a sequence of organisms in which a gradual transfer of matter and energy occurs from source to consumer). Organisms of the next link eat the organisms of the previous link, and thus a chain transfer of energy and matter occurs, which underlies the cycle of substances in nature. With each transfer from link to link, a large part (up to 80-90%) of the potential energy is lost, dissipated in the form of heat. For this reason, the number of links (types) in the food chain is limited and usually does not exceed 4-5. The stability of a biocenosis is determined by the diversity of its species composition. Producers- organisms capable of synthesizing organic substances from inorganic ones, that is, all autotrophs. Consumers- heterotrophs, organisms that consume ready-made organic substances created by autotrophs (producers). Unlike decomposers
, consumers are not able to decompose organic substances into inorganic ones. Decomposers- microorganisms (bacteria and fungi) that destroy dead remains of living beings, turning them into inorganic and simple organic compounds.3. Name the organisms that should be in the missing place in the following food chains.
1) Spider, fox
2) tree-eater-caterpillar, snake-hawk
3) caterpillar
4. From the proposed list of living organisms, create a trophic network:
grass, berry bush, fly, tit, frog, grass snake, hare, wolf, rotting bacteria, mosquito, grasshopper. Indicate the amount of energy that moves from one level to another.
1. Grass (100%) - grasshopper (10%) - frog (1%) - snake (0.1%) - rotting bacteria (0.01%).
2. Shrub (100%) - hare (10%) - wolf (1%) - rotting bacteria (0.1%).
3. Grass (100%) - fly (10%) - tit (1%) - wolf (0.1%) - rotting bacteria (0.01%).
4. Grass (100%) - mosquito (10%) - frog (1%) - snake (0.1%) - rotting bacteria (0.01%).
5. Knowing the rule for the transfer of energy from one trophic level to another (about 10%), build a pyramid of biomass for the third food chain (task 1). Plant biomass is 40 tons.
Grass (40 tons) -- grasshopper (4 tons) -- sparrow (0.4 tons) -- fox (0.04).
6. Conclusion: what do the rules of ecological pyramids reflect?
The rule of ecological pyramids very conditionally conveys the pattern of energy transfer from one level of nutrition to the next in the food chain. These graphic models were first developed by Charles Elton in 1927. According to this pattern, the total mass of plants should be an order of magnitude greater than that of herbivorous animals, and the total mass of herbivorous animals should be an order of magnitude greater than that of first-level predators, etc. to the very end of the food chain.
Laboratory work No. 1
Topic: Studying the structure of plant and animal cells under a microscope
Goal of the work: get acquainted with the structural features of plant and animal cells, show the fundamental unity of their structure.
Equipment: microscope , onion scale skin , epithelial cells from the human oral cavity, teaspoon, cover glass and slide glass, blue ink, iodine, notebook, pen, pencil, ruler
Progress:
1. Separate a piece of the skin covering it from the scales of the bulb and place it on a glass slide.
2. Apply a drop of a weak aqueous solution of iodine to the preparation. Cover the preparation with a coverslip.
3. Use a teaspoon to remove some mucus from the inside of your cheek.
4. Place the mucus on a slide and tint with blue ink diluted in water. Cover the preparation with a coverslip.
5. Examine both preparations under a microscope.
6. Enter the comparison results in tables 1 and 2.
7. Draw a conclusion about the work done.
Option #1.
Table No. 1 “Similarities and differences between plant and animal cells.”
| Features of cell structure | plant cell | animal cell |
| Drawing | ||
| Similarities | Nucleus, cytoplasm, cell membrane, mitochondria, ribosomes, Golgi complex, lysosomes, abilities for self-renewal, self-regulation. | Nucleus, cytoplasm, cell membrane, mitochondria, ribosomes, lysosomes, Golgi complex, abilities for self-renewal, self-regulation. |
| Features of difference | There are plastids (chroloplasts, leucoplasts, chromoplasts), a vacuole, a thick cell wall consisting of cellulose, capable of photosynthesis. Vacuole – contains cell sap and toxic substances accumulate in it (plant leaves). | Centriole, elastic cell wall, glycocalyx, cilia, flagella, heterotrophs, storage substance - glycogen, integral cell reactions (pinocytosis, endocytosis, exocytosis, phagocytosis). |
Option number 2.
Table No. 2 “Comparative characteristics of plant and animal cells.”
| Cells | Cytoplasm | Core | Dense cell wall | Plastids |
| Vegetable | Cytoplasm consists of a thick, viscous substance in which all other parts of the cell are located. It has a special chemical composition. Various biochemical processes take place in it, ensuring the vital activity of the cell. In a living cell, the cytoplasm is constantly moving, flowing throughout the entire volume of the cell; it can increase in volume. | contains genetic information that performs the main functions: storage, transmission and implementation of hereditary information, ensuring protein synthesis. | There is a thick cell wall consisting of cellulose. | There are plastids (chroloplasts, leucoplasts, chromoplasts). Chloroplasts are green plastids that are found in the cells of photosynthetic eukaryotes. With their help, photosynthesis occurs. Chloroplasts contain chlorophyll, the formation of starch and the release of oxygen. Leukoplasts - synthesize and accumulate starch (so-called amyloplasts), fats, and proteins. Found in plant seeds, roots, stems and flower petals (attract insects for pollination). Chromoplasts - contain only yellow, orange and reddish pigments from a number of carotenes. Found in plant fruits, they give color to vegetables, fruits, berries and flower petals (attract insects and animals for pollination and distribution in nature). |
| Animal | Present, it consists of a colloidal solution of proteins and other organic substances, 85% of this solution is water, 10% are proteins and 5% are other compounds. | containing genetic information (DNA molecules), performing the main functions: storage, transmission and implementation of hereditary information, ensuring protein synthesis. | Present, cell wall elastic, glycalyx | No. |
4. State your conclusion.
Conclusion: _All plants and animals are made up of cells. A cell is an elementary unit of structure and vital activity of all living organisms. A plant cell has a thick cellulose membrane, vacuole and plastids; animals, unlike plants, have a thin glycogen membrane (carries out pinocytosis, endocytosis, exocytosis, phagocytosis), and there are no vacuoles (except in protozoa).
Laboratory work No. 2
1. Producers(producers) produce organic substances from inorganic ones. These are plants, as well as photo- and chemosynthetic bacteria.
2. Consumers(consumers) consume finished organic substances.
- 1st order consumers feed on producers (cow, carp, bee)
- 2nd order consumers feed on first order consumers (wolf, pike, wasp)
etc.
3. Decomposers(destroyers) destroy (mineralize) organic substances to inorganic ones - bacteria and fungi.
Example of a food chain: cabbage → cabbage white caterpillar → tit → hawk. The arrow in the food chain is directed from the one who is eaten towards the one who eats. The first link of the food chain is the producer, the last is the higher-order consumer or decomposer.
The food chain cannot contain more than 5-6 links, because when moving to each next link, 90% of the energy is lost ( 10% rule, rule of the ecological pyramid). For example, a cow ate 100 kg of grass, but gained weight only by 10 kg, because...
a) she did not digest part of the grass and threw it away with feces
b) some of the digested grass was oxidized to carbon dioxide and water to produce energy.
Each subsequent link in the food chain weighs less than the previous one, so the food chain can be represented as biomass pyramids(at the bottom are producers, there are the most of them, at the very top are consumers of the highest order, there are the fewest of them). In addition to the biomass pyramid, you can build a pyramid of energy, numbers, etc.
Establish a correspondence between the function performed by an organism in a biogeocenosis and the representatives of the kingdom performing this function: 1) plants, 2) bacteria, 3) animals. Write the numbers 1, 2 and 3 in the correct order.
A) the main producers of glucose in the biogeocenosis
B) primary consumers of solar energy
C) mineralize organic matter
D) are consumers of different orders
D) ensure the absorption of nitrogen by plants
E) transfer substances and energy in food chains
Answer
Answer
Choose three options. Algae in a reservoir ecosystem constitute the initial link in most food chains, since they
1) accumulate solar energy
2) absorb organic substances
3) capable of chemosynthesis
4) synthesize organic substances from inorganic ones
5) provide energy and organic matter to animals
6) grow throughout life
Answer
Choose one, the most correct option. In the ecosystem of a coniferous forest, consumers of the 2nd order include
1) spruce
2) forest mice
3) taiga ticks
4) soil bacteria
Answer
1. Establish the correct sequence of links in the food chain using all named objects
1) ciliate-slipper
2) Bacillus subtilis
3) seagull
4) fish
5) mollusk
6) silt
Answer
2. Establish the correct sequence of links in the food chain, using all the named representatives
1) hedgehog
2) field slug
3) eagle
4) plant leaves
5) fox
Answer
3. Place the organisms in the correct order in the decomposition chain (detritus). Write down the corresponding sequence of numbers.
1) small carnivorous predators
2) animal remains
3) insectivores
4) saprophagous beetles
Answer
4. Arrange the organisms in the correct order in the detrital food chain. Write down the corresponding sequence of numbers.
1) mouse
2) honey fungus
3) hawk
4) rotten stump
5) snake
Answer
5. Establish the sequence of organisms in the food chain, starting with the organism that absorbs sunlight. Write down the corresponding sequence of numbers.
1) gypsy moth caterpillar
2) linden
3) common starling
4) sparrowhawk
5) fragrant beetle
Answer
6. Establish the correct sequence of organisms in the food chain.
1) wheat grains
2) red fox
3) bug harmful turtle
4) steppe eagle
5) common quail
Answer
7. Establish the sequence of arrangement of organisms in the food chain. Write down the corresponding sequence of numbers.
1) frog
2) already
3) butterfly
4) meadow plants
Answer
8. Establish the sequence of organisms in the food chain. Write down the corresponding sequence of numbers.
1) fish fry
2) algae
3) perch
4) daphnia
Answer
9. Establish the sequence in which the listed objects should be located in the food chain.
1) cross spider
2) weasel
3) dung fly larva
4) frog
5) manure
Answer
10. Establish the sequence of objects in the food chain of an ecosystem. Write down the corresponding sequence of numbers.
1) marten
2) wolf
3) leaf litter
4) earthworm
5) mole
Answer
Establish a correspondence between the characteristics of organisms and the functional group to which it belongs: 1) producers, 2) decomposers
A) absorb carbon dioxide from the environment
B) synthesize organic substances from inorganic ones
B) include plants, some bacteria
D) feed on ready-made organic substances
D) include saprotrophic bacteria and fungi
E) decompose organic substances into minerals
Answer
1. Choose three correct answers out of six. Write down the numbers under which they are indicated. Producers include
1) pathogenic prokaryotes
2) brown algae
3) phytophages
4) cyanobacteria
5) green algae
6) symbiont mushrooms
Answer
2. Choose three correct answers out of six and write down the numbers under which they are indicated. Producers of biocenoses include
1) penicillium mushroom
2) lactic acid bacterium
3) silver birch
4) white planaria
5) camel thorn
6) sulfur bacteria
Answer
3. Choose three correct answers out of six and write down the numbers under which they are indicated. Producers include
1) freshwater hydra
2) cuckoo flax
3) cyanobacterium
4) champignon
5) ulotrix
6) planaria
Answer
FORMED: Choose three correct answers out of six and write down the numbers under which they are indicated. Producers include
A) yeast
Choose three correct answers out of six and write down the numbers under which they are indicated. In biogeocenosis, heterotrophs, unlike autotrophs,
1) are producers
2) provide a change in ecosystems
3) increase the supply of molecular oxygen in the atmosphere
4) extract organic substances from food
5) convert organic residues into mineral compounds
6) act as consumers or decomposers
Answer
1. Establish a correspondence between ecological groups in the ecosystem and their characteristics: 1) producers, 2) consumers. Write numbers 1 and 2 in the order corresponding to the letters.
A) are autotrophs
B) heterotrophic organisms
C) the main representatives are green plants
D) produce secondary products
D) synthesize organic compounds from inorganic substances
Answer
Answer
Establish a correspondence between the characteristics of organisms and functional groups in the ecosystem: 1) consumers, 2) producers, 3) decomposers. Write numbers 1-3 in the order corresponding to the letters.
A) return free nitrogen to the atmosphere
B) form primary production
B) form organic substances as a result of chemosynthesis
D) constitute the second trophic level
D) mineralize organic residues
Answer
1. Establish a correspondence between organisms and functional groups in the ecosystems to which they belong: 1) producers, 2) consumers. Write numbers 1 and 2 in the order corresponding to the letters.
A) naked slug
B) common mole
B) gray toad
D) black polecat
D) kale
E) common cress
Answer
2. Establish a correspondence between organisms and functional groups: 1) producers, 2) consumers. Write numbers 1 and 2 in the order corresponding to the letters.
A) sulfur bacteria
B) field mouse
B) meadow bluegrass
D) honey bee
D) creeping wheatgrass
Answer
Establish the sequence of the main stages of the cycle of substances in the ecosystem, starting with photosynthesis. Write down the corresponding sequence of numbers.
1) destruction and mineralization of organic residues
2) primary synthesis of organic substances from inorganic substances by autotrophs
3) use of organic substances by consumers of the second order
4) use of the energy of chemical bonds by herbivorous animals
5) use of organic substances by consumers of the third order
Answer
1. Establish a correspondence between organisms and their function in the forest ecosystem: 1) producers, 2) consumers, 3) decomposers. Write the numbers 1, 2 and 3 in the correct order.
A) horsetails and ferns
B) molds
C) tinder fungi that live on living trees
D) birds
D) birch and spruce
E) putrefaction bacteria
Answer
2. Establish a correspondence between organisms - inhabitants of the ecosystem and the functional group to which they belong: 1) producers, 2) consumers, 3) decomposers.
A) mosses, ferns
B) toothless and pearl barley
B) spruce, larches
D) molds
D) putrefactive bacteria
E) amoebas and ciliates
Answer
3. Establish a correspondence between organisms and functional groups in the ecosystems to which they belong: 1) producers, 2) consumers, 3) decomposers. Write numbers 1-3 in the order corresponding to the letters.
A) spirogyra
B) sulfur bacteria
B) mukor
D) freshwater hydra
D) kelp
E) putrefaction bacteria
Answer
4. Establish a correspondence between the organism and the functional group to which this organism belongs: 1) producers, 2) consumers, 3) decomposers. Write numbers 1-3 in the order corresponding to the letters.
A) dandelion
B) putrefactive bacterium
B) warty birch
D) grass frog
D) common mole
E) penicillium mold
Answer
Choose three correct answers out of six and write down the numbers under which they are indicated in the table. Which of the following organisms are consumers of finished organic matter in the pine forest community?
1) soil green algae
2) common viper
3) sphagnum moss
4) pine undergrowth
5) black grouse
6) wood mouse
Answer
1. Establish a correspondence between an organism and its membership in a certain functional group: 1) producers, 2) decomposers. Write numbers 1 and 2 in the correct order.
A) red clover
B) chlamydomonas
B) putrefaction bacterium
D) birch
D) kelp
E) soil bacterium
Answer
2. Establish a correspondence between the organism and the trophic level at which it is located in the ecosystem: 1) Producer, 2) Reducer. Write numbers 1 and 2 in the correct order.
A) Sphagnum
B) Aspergillus
B) Laminaria
D) Pine
D) Penicill
E) Putrefactive bacteria
Answer
3. Establish a correspondence between organisms and their functional groups in the ecosystem: 1) producers, 2) decomposers. Write numbers 1 and 2 in the order corresponding to the letters.
A) sulfur bacteria
B) cyanobacterium
B) fermentation bacterium
D) soil bacterium
D) mukor
E) kelp
Answer
Choose three options. What is the role of bacteria and fungi in the ecosystem?
1) convert organic substances of organisms into minerals
2) ensure the closure of the circulation of substances and energy conversion
3) form primary production in the ecosystem
4) serve as the first link in the food chain
5) form inorganic substances available to plants
6) are consumers of the second order
Answer
Choose three correct answers out of six and write down the numbers under which they are indicated. What role do decomposers play in an ecosystem?
1) form primary organic matter
2) consume detritus
3) serve as food for predator plants
4) release soluble mineral salts into the medium
5) serve as the initial link in the pasture food chain
6) ensure the closure of the cycle of substances
Answer
1. Establish a correspondence between a group of plants or animals and its role in the pond ecosystem: 1) producers, 2) consumers. Write numbers 1 and 2 in the correct order.
A) coastal vegetation
B) fish
B) amphibian larvae
D) phytoplankton
D) bottom plants
E) shellfish
Answer
2. Establish a correspondence between the inhabitants of the terrestrial ecosystem and the functional group to which they belong: 1) consumers, 2) producers. Write numbers 1 and 2 in the order corresponding to the letters.
A) alder
B) typograph beetle
B) elm
D) sorrel
D) crossbill
E) forty
Answer
3. Establish a correspondence between the organism and the functional group of the biocenosis to which it belongs: 1) producers, 2) consumers. Write numbers 1 and 2 in the order corresponding to the letters.
A) tinder fungus
B) creeping wheatgrass
B) sulfur bacteria
D) Vibrio cholerae
D) ciliate-slipper
E) malarial plasmodium
Answer
4. Establish a correspondence between the examples and ecological groups in the food chain: 1) producers, 2) consumers. Write numbers 1 and 2 in the order corresponding to the letters.
A) hare
B) wheat
B) earthworm
D) tit
D) kelp
E) small pond snail
Answer
1. Establish a correspondence between animals and their roles in the biogeocenosis of the taiga: 1) consumer of the 1st order, 2) consumer of the 2nd order. Write numbers 1 and 2 in the correct order.
A) nutcracker
B) goshawk
B) common fox
D) red deer
D) brown hare
E) common wolf
Answer
2. Establish a correspondence between the animal and its role in the savanna: 1) consumer of the first order, 2) consumer of the second order. Write numbers 1 and 2 in the order corresponding to the letters.
A) antelope
B) lion
B) cheetah
D) rhinoceros
D) ostrich
E) neck
Answer
3. Establish a correspondence between organisms and the functional groups of the ecosystem to which they belong: 1) consumer of the 1st order, 2) consumer of the 2nd order. Write numbers 1 and 2 in the order corresponding to the letters.
A) river beaver
B) wild rabbit
B) slug
D) lake frog
D) fur seals
Answer
Answer
Establish a correspondence between the characteristics of organisms and the functional group to which they belong: 1) Producers, 2) Decomposers. Write numbers 1 and 2 in the correct order.
A) Is the first link in the food chain
B) Synthesize organic substances from inorganic ones
B) Use the energy of sunlight
D) They feed on ready-made organic substances
D) Return minerals to ecosystems
E) Decompose organic substances into minerals
Answer
Choose three correct answers out of six and write down the numbers under which they are indicated. In the biological cycle occurs:
1) decomposition of producers by consumers
2) synthesis of organic substances from inorganic by producers
3) decomposition of consumers by decomposers
4) consumption of finished organic substances by producers
5) nutrition of producers by consumers
6) consumption of finished organic substances by consumers
Answer
1. Select organisms that are decomposers. Three correct answers out of six and write down the numbers under which they are indicated.
1) penicillium
2) ergot
3) putrefactive bacteria
4) mukor
5) nodule bacteria
6) sulfur bacteria
Answer
2. Choose three correct answers out of six and write down the numbers under which they are indicated. Decomposers in an ecosystem include
1) rotting bacteria
2) mushrooms
3) nodule bacteria
4) freshwater crustaceans
5) saprophytic bacteria
6) chafers
Answer
Choose three correct answers out of six and write down the numbers under which they are indicated. Which of the following organisms are involved in the decomposition of organic residues to mineral ones?
1) saprotrophic bacteria
2) mole
3) penicillium
4) chlamydomonas
5) white hare
6) mukor
Answer
Choose one, the most correct option. What do fungi and bacteria have in common?
1) the presence of cytoplasm with organelles and a nucleus with chromosomes
2) asexual reproduction using spores
3) their destruction of organic substances to inorganic ones
4) existence in the form of unicellular and multicellular organisms
Answer
Choose three correct answers out of six and write down the numbers under which they are indicated. In a mixed forest ecosystem, the first trophic level is occupied by
1) granivorous mammals
2) warty birch
3) black grouse
4) gray alder
5) angustifolia fireweed
6) dragonfly rocker
Answer
1. Choose three correct answers out of six and write down the numbers under which they are indicated. The second trophic level in a mixed forest ecosystem is occupied by
1) moose and roe deer
2) hares and mice
3) bullfinches and crossbills
4) nuthatches and tits
5) foxes and wolves
6) hedgehogs and moles
Answer
2. Choose three correct answers out of six and write down the numbers under which they are indicated. The second trophic level of the ecosystem includes
1) Russian muskrat
2) black grouse
3) cuckoo flax
4) reindeer
5) European marten
6) field mouse
Answer
Choose three correct answers out of six and write down the numbers under which they are indicated. In food chains, first-order consumers are
1) echidna
2) locusts
3) dragonfly
4) fox
5) moose
6) sloth
Answer
Analyze the table “Trophic levels in the food chain.” For each lettered cell, select the appropriate term from the list provided. Write down the selected numbers in the order corresponding to the letters.
1) secondary predators
2) first level
3) saprotrophic bacteria
4) decomposers
5) second-order consumers
6) second level
7) producers
8) tertiary predators
Answer
Analyze the table “Trophic levels in the food chain.” Fill in the blank cells of the table using the terms in the list. For each lettered cell, select the appropriate term from the list provided. Write down the selected numbers in the order corresponding to the letters.
List of terms:
1) primary predators
2) first level
3) saprotrophic bacteria
4) decomposers
5) consumers of the first order
6) heterotrophs
7) third level
8) secondary predators
Answer
Analyze the table “Functional groups of organisms in an ecosystem.” For each lettered cell, select the appropriate term from the list provided. Write down the selected numbers in the order corresponding to the letters.
1) viruses
2) eukaryotes
3) saprotrophic bacteria
4) producers
5) algae
6) heterotrophs
7) bacteria
8) mixotrophs
Answer
Look at the picture of a food chain and indicate (A) the type of food chain, (B) the producer, and (C) the second-order consumer. For each lettered cell, select the appropriate term from the list provided. Write down the selected numbers in the order corresponding to the letters.
1) detrital
2) Canadian pondweed
3) osprey
4) pasture
5) big pond snail
6) green frog
Answer
Answer
Choose three correct answers out of six and write down the numbers under which they are indicated. Decomposers in the forest ecosystem participate in the cycle of substances and energy transformations, since
1) synthesize organic substances from minerals
2) release energy contained in organic residues
3) accumulate solar energy
4) decompose organic matter
5) promote the formation of humus
6) enter into symbiosis with consumers
Answer
Choose three options. In a forest ecosystem, frogs are considered consumers, since they
1) consume ready-made organic substances
2) participate in the decomposition of organic residues
3) feed on insects
4) have a patronizing connotation
5) constitute the third trophic level
6) synthesize organic substances from inorganic ones
Answer
Choose two correct answers out of five and write down the numbers under which they are indicated. Environmental terms include
1) heterosis
2) population
3) outbreeding
4) consumer
5) divergence
Answer
Choose three correct answers out of six and write down the numbers under which they are indicated. Which of the following animals can be classified as consumers of the second order?
1) gray rat
2) Colorado potato beetle
3) dysenteric amoeba
4) grape snail
5) ladybug
6) honey bee
Answer
Answer
Establish the sequence of increase in the biomass of organisms in accordance with the rule of the ecological pyramid, starting with the smallest. Write down the corresponding sequence of numbers.
1) squid, octopus
2) polar bear
3) plankton
4) crustaceans
5) pinnipeds
Answer
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