In preparing the answer to this question, I “shoveled” quite a lot of sources and I can say with a high degree of confidence that the food chain described in the task in real life can happen in a very rare case. And all because of the introduction of a tick into this chain. His place in this chain can be both at the beginning and at the end.
food chain
This is the name of the relationship between living organisms, where one of its participants eats another. In relation to the question, in descending order, one producer (manufacturer) and three consumers (consumer) are presented:
The problem with this chain is where the tick comes from, and even a special bird species.
But knowing our education system, this is exactly the kind of chain construction that the teacher will expect.
Why is such a chain unlikely?
With the first link of the chain, everything is clear and with the second one too: cones grew on the tree and the squirrel ate them. All this is permissible. Suppose that a tick appears next, which must first feed on a squirrel, and then switch to a hawk when it catches it. The squirrel is a rodent that lives in trees, rarely descending to the ground. A tick lives only on the ground in the grass. Let's make a hypothesis that the squirrel descended to the ground and there, in the grass, a tick attached itself to it. Then this tick will die along with the squirrel when it becomes the prey of the hawk, because the species of forest ticks do not attack the birds. In a hawk, a tick can appear only with an aviary lifestyle, and such ticks are called down-eaters.
1. Producers(manufacturers) produce organic substances from inorganic ones. These are plants, as well as photo- and chemosynthetic bacteria.
2. Consumers(consumers) consume the finished organic matter.
- consumers of the 1st order feed on producers (cow, carp, bee)
- consumers of the 2nd order feed on consumers of the first (wolf, pike, wasp)
etc.
3. decomposers(destroyers) destroy (mineralize) organic substances to inorganic - bacteria and fungi.
Food chain example: cabbage → cabbage white caterpillar → tit → hawk. The arrow in the food chain is directed from the one being eaten towards the one who is eating. The first link in the food chain is a producer, the last is a 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, the rule of the ecological pyramid). For example, a cow ate 100 kg of grass, but gained only 10 kg fat, because.
a) she did not digest part of the grass and threw it away with feces
b) part of the digested grass was oxidized to carbon dioxide and water for 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 manufacturers, they are the most, at the very top are consumers of a higher order, they are the least). In addition to the pyramid of biomass, you can build a pyramid of energy, abundance, etc.
Establish a correspondence between the function performed by the organism in the 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
B) mineralize organic matter
D) are consumers of different orders
D) provide nitrogen uptake by plants
E) transfer substances and energy in food chains
Answer
Answer
Choose three options. Algae in the ecosystem of the reservoir constitute the initial link in most food chains, as they
1) accumulate solar energy
2) absorb organic matter
3) capable of chemosynthesis
4) synthesize organic substances from inorganic
5) provide energy and organic matter to animals
6) grow throughout life
Answer
Choose one, the most correct option. In the coniferous forest ecosystem, second-order consumers include
1) Norway spruce
2) forest mice
3) taiga ticks
4) soil bacteria
Answer
1. Establish the correct sequence of links in the food chain using all the named objects
1) infusoria-shoe
2) hay stick
3) seagull
4) fish
5) clam
6) silt
Answer
2. Set 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. Put the organisms in the correct order in the decomposition chain (detritus). Write down the corresponding sequence of numbers.
1) small carnivores
2) animal remains
3) insectivorous animals
4) saprophage beetles
Answer
4. Put the organisms in the correct order in the detrital food chain. Write down the corresponding sequence of numbers.
1) mouse
2) honey agaric
3) hawk
4) rotten stump
5) snake
Answer
5. Set 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) odorous beetle
Answer
6. Set the correct sequence of organisms in the food chain.
1) wheat grains
2) red fox
3) a bug is a harmful turtle
4) steppe eagle
5) common quail
Answer
7. Establish the sequence of organisms in the food chain. Write down the corresponding sequence of numbers.
1) frog
2) already
3) butterfly
4) meadow plants
Answer
8. Set 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 order in which the listed objects should be located in the food chain.
1) spider-cross
2) caress
3) dung fly larva
4) frog
5) manure
Answer
10. Establish the sequence of objects in the food chain of the 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 characteristic 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
B) include plants, some bacteria
D) feed on ready-made organic substances
D) include saprotrophic bacteria and fungi
E) break down organic matter into minerals
Answer
1. Choose three correct answers from six. Write down the numbers under which they are indicated. The producers are
1) pathogenic prokaryotes
2) brown algae
3) phytophages
4) cyanobacteria
5) green algae
6) symbiont mushrooms
Answer
2. Choose three correct answers from six and write down the numbers under which they are indicated. The producers of biocenoses include
1) penicillium mushroom
2) lactic acid bacterium
3) drooping birch
4) white planaria
5) camel thorn
6) sulfur bacteria
Answer
3. Choose three correct answers from six and write down the numbers under which they are indicated. The producers are
1) freshwater hydra
2) cuckoo flax
3) cyanobacteria
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. The producers are
A) yeast
Choose three correct answers from six and write down the numbers under which they are indicated. In the 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 matter 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 down the numbers 1 and 2 in the order corresponding to the letters.
A) they 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 down the numbers 1-3 in the order corresponding to the letters.
A) return free nitrogen to the atmosphere
B) form primary products
B) form organic substances as a result of chemosynthesis
D) make up 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 down the numbers 1 and 2 in the order corresponding to the letters.
A) naked slug
B) common mole
B) gray toad
D) black ferret
D) leafy cabbage
E) common colza
Answer
2. Establish a correspondence between organisms and functional groups: 1) producers, 2) consumers. Write down the 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 an ecosystem, starting with photosynthesis. Write down the corresponding sequence of numbers.
1) destruction and mineralization of organic residues
2) primary synthesis by autotrophs of organic substances from inorganic
3) the use of organic substances by consumers of the second order
4) the use of the energy of chemical bonds by herbivorous animals
5) the use of organic substances by consumers of the III 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) fungi
B) tinder fungi that live on living trees
D) birds
D) birch and spruce
E) decay 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 barley
B) spruce, larch
D) fungi
D) putrefactive bacteria
E) amoeba 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 down the numbers 1-3 in the order corresponding to the letters.
A) spirogyra
B) sulfur bacteria
B) mucor
D) freshwater hydra
D) kelp
E) decay 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 down the numbers 1-3 in the order corresponding to the letters.
A) dandelion officinalis
B) putrefactive bacteria
B) warty birch
D) common frog
D) common mole
E) mold fungus penicillium
Answer
Choose three correct answers from six and write down the numbers under which they are indicated in the table. Which of the following organisms are consumers of ready-made organic matter in a pine forest community?
1) soil green algae
2) common viper
3) sphagnum moss
4) pine undergrowth
5) black grouse
6) forest mouse
Answer
1. Establish a correspondence between an organism and its belonging to a certain functional group: 1) producers, 2) decomposers. Write the numbers 1 and 2 in the correct sequence.
A) red clover
B) chlamydomonas
B) putrefactive bacteria
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) Decomposer. Write the numbers 1 and 2 in the correct order.
A) sphagnum
B) Aspergillus
B) Laminaria
D) Pine
D) Penicillium
E) putrefactive bacteria
Answer
3. Establish a correspondence between organisms and their functional groups in the ecosystem: 1) producers, 2) decomposers. Write down the numbers 1 and 2 in the order corresponding to the letters.
A) sulfur bacterium
B) cyanobacteria
B) fermentation bacteria
D) soil bacterium
D) mucor
E) kelp
Answer
Choose three options. What is the role of bacteria and fungi in an ecosystem?
1) convert organic substances of organisms into minerals
2) ensure the closure of the circulation of substances and the transformation of energy
3) form the 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 from 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 circulation 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 the numbers 1 and 2 in the correct order.
A) coastal vegetation
B) fish
B) larvae of amphibians
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 down the numbers 1 and 2 in the order corresponding to the letters.
A) alder
B) typographer beetle
B) elm
D) sour
D) crossbill
E) magpie
Answer
3. Establish a correspondence between the organism and the functional group of the biocenosis, to which it belongs: 1) producers, 2) consumers. Write down the numbers 1 and 2 in the order corresponding to the letters.
A) tinder fungus
B) creeping wheatgrass
B) sulfur bacterium
D) cholera vibrio
D) infusoria-shoe
E) malarial plasmodium
Answer
4. Establish a correspondence between examples and ecological groups in the food chain: 1) producers, 2) consumers. Write down the numbers 1 and 2 in the order corresponding to the letters.
A) 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 the numbers 1 and 2 in the correct order.
A) nutcracker
B) goshawk
B) common fox
D) red deer
D) hare
E) common wolf
Answer
2. Establish a correspondence between the animal and its role in the savannah: 1) consumer of the first order, 2) consumer of the second order. Write down the numbers 1 and 2 in the order corresponding to the letters.
A) antelope
B) lion
B) a cheetah
D) rhinoceros
D) ostrich
E) neck
Answer
3. Establish a correspondence between organisms and functional groups of the ecosystem to which they belong: 1) consumer of the 1st order, 2) consumer of the 2nd order. Write down the 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 the numbers 1 and 2 in the correct order.
A) is the first link in the food chain
B) synthesize organic substances from inorganic
C) use the energy of sunlight
D) They feed on ready-made organic substances.
D) Return minerals to ecosystems
E) decompose organic matter into minerals
Answer
Choose three correct answers from 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 producers
3) decomposition of consumers by decomposers
4) consumption by producers of finished organic substances
5) nutrition of producers with consumers
6) consumption of finished organic substances by consumers
Answer
1. Select organisms related to 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 from six and write down the numbers under which they are indicated. The decomposers in an ecosystem are
1) decay bacteria
2) mushrooms
3) nodule bacteria
4) freshwater crustaceans
5) bacteria-saprophytes
6) may beetles
Answer
Choose three correct answers from 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 minerals?
1) bacteria-saprotrophs
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 a cytoplasm with organelles and a nucleus with chromosomes
2) asexual reproduction using spores
3) their destruction of organic substances to inorganic
4) existence in the form of unicellular and multicellular organisms
Answer
Choose three correct answers from 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) fireweed
6) dragonfly rocker
Answer
1. Choose three correct answers from 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 from six and write down the numbers under which they are indicated. The second trophic level of an ecosystem is
1) Russian desman
2) black grouse
3) cuckoo flax
4) reindeer
5) European marten
6) field mouse
Answer
Choose three correct answers from six and write down the numbers under which they are indicated. In food chains, first-order consumers are
1) echidna
2) locust
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 chosen numbers, in the order corresponding to the letters.
1) secondary predators
2) first level
3) saprotrophic bacteria
4) decomposers
5) consumers of the second order
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 given in the list. For each lettered cell, select the appropriate term from the list provided. Write down the chosen 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 the ecosystem." For each lettered cell, select the appropriate term from the list provided. Write down the chosen 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 the food chain and indicate (A) the type of food chain, (B) the producer and (C) the consumer of the second order. For each lettered cell, select the appropriate term from the list provided. Write down the chosen numbers, in the order corresponding to the letters.
1) detritus
2) Canadian pondweed
3) osprey
4) pasture
5) big pond
6) green frog
Answer
Answer
Choose three correct answers from six and write down the numbers under which they are indicated. Decomposers in the forest ecosystem are involved in the cycle of substances and energy transformations, since
1) synthesize organic substances from mineral
2) release the energy contained in organic residues
3) accumulate solar energy
4) decompose organic matter
5) contribute to the formation of humus
6) enter into symbiosis with consumers
Answer
Choose three options. In the ecosystem of the forest, frogs are considered consumers, since they
1) consume ready-made organic matter
2) participate in the decomposition of organic residues
3) eat insects
4) have a patronizing color
5) make up the third trophic level
6) synthesize organic substances from inorganic
Answer
Choose two correct answers from five and write down the numbers under which they are indicated. Ecological terms are
1) heterosis
2) population
3) outbreeding
4) consumer
5) divergence
Answer
Choose three correct answers from six and write down the numbers under which they are indicated. Which of the following animals can be attributed to 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
Set the sequence of growth of 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
© D.V. Pozdnyakov, 2009-2019
Target: expand knowledge of biotic environmental factors.
Equipment: herbarium plants, stuffed chordates (fish, amphibians, reptiles, birds, mammals), insect collections, animal wet preparations, illustrations of various plants and animals.
Working process:
1. Use the equipment and make up two power circuits. Remember that a chain always starts with a producer and ends with a decomposer.
Plants → insects→lizard → bacteria
Plants → Grasshopper→ frog → bacteria
Recall your observations in nature and make two food chains. Sign producers, consumers (1st and 2nd orders), decomposers.
Violet → Springtails→predatory mites→carnivorous 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 the biocenosis? Formulate a conclusion.
Output:
food (trophic) chain- rows of species of plants, animals, fungi and microorganisms that are related to each other by relationships: food - consumer (a sequence of organisms in which there is a phased transfer of matter and energy 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 is carried out, 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, dissipating in the form of heat. For this reason, the number of links (species) in the food chain is limited and usually does not exceed 4-5. The stability of the biocenosis is determined by the diversity of its species composition. Producers- organisms capable of synthesizing organic substances from inorganic, that is, all autotrophs. Consumers- heterotrophs, organisms that consume ready-made organic substances created by autotrophs (producers). Unlike reducers
, consumers are not able to decompose organic substances to inorganic ones. Decomposers- microorganisms (bacteria and fungi) that destroy the dead remains of living beings, turning them into inorganic and simple organic compounds.3. Name the organisms that should be in the missing place of the following food chains.
1) Spider, fox
2) caterpillar tree eater, snake hawk
3) caterpillar
4. From the proposed list of living organisms, make a food web:
grass, berry bush, fly, titmouse, frog, snake, hare, wolf, decay bacteria, mosquito, grasshopper. Indicate the amount of energy that passes from one level to another.
1. Grass (100%) - grasshopper (10%) - frog (1%) - already (0.1%) - decay bacteria (0.01%).
2. Shrub (100%) - hare (10%) - wolf (1%) - decay bacteria (0.1%).
3. Grass (100%) - fly (10%) - titmouse (1%) - wolf (0.1%) - decay bacteria (0.01%).
4. Grass (100%) - mosquito (10%) - frog (1%) - already (0.1%) - decay bacteria (0.01%).
5. Knowing the rule of energy transfer from one trophic level to another (about 10%), build a biomass pyramid of 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. For the first time, these graphic models were developed by C. Elton in 1927. According to this regularity, 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, and so on. to the very end of the food chain.
Lab #1
Topic: Studying the structure of plant and animal cells under a microscope
Objective: to get acquainted with the structural features of the cells of plants and animal organisms, to show the fundamental unity of their structure.
Equipment: microscope , bulb scale skin , epithelial cells from the human oral cavity, teaspoon, coverslip and slide, blue ink, iodine, notebook, pen, pencil, ruler
Working process:
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 specimen with a cover slip.
3. Remove a little mucus from the inside of the cheek with a teaspoon.
4. Place the slime on a glass slide and tint with blue ink diluted in water. Cover the specimen with a cover slip.
5. Examine both preparations under a microscope.
6. Record the comparison results in Tables 1 and 2.
7. Make a conclusion about the work done.
Option number 1.
Table No. 1 "Similarities and differences between plant and animal cells."
| Features of the structure of the cell | plant cell | animal cage |
| Picture | ||
| similarities | Nucleus, cytoplasm, cell membrane, mitochondria, ribosomes, Golgi complex, lysosomes, self-renewal, self-regulation abilities. | Nucleus, cytoplasm, cell membrane, mitochondria, ribosomes, lysosomes, Golgi complex, self-renewal, self-regulation abilities. |
| Features of difference | There are plastids (chloroplasts, leukoplasts, chromoplasts), a vacuole, a thick cell wall consisting of cellulose, capable of photosynthesis. Vacuole - contains cell sap and toxic substances (leaves of plants) accumulate in it. | 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 | The 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, which ensure 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 size. | contains genetic information that performs the main functions: storage, transmission and implementation of hereditary information with the provision of protein synthesis. | There is a thick cell wall made of cellulose. | Plastids (chloroplasts, leukoplasts, chromoplasts) are present. Chloroplasts are green plastids found in photosynthetic eukaryotic cells. They are used for photosynthesis. Chloroplasts contain chlorophyll, the formation of starch with the release of oxygen. Leukoplasts - synthesize and accumulate starch (the so-called amyloplasts), fats, proteins. They are 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. They are found in the fruits of plants, give color to vegetables, fruits, berries and flower petals (attract insects and animals for pollination and distribution in nature). |
| Animal | It is present, it consists of a colloidal solution of proteins and other organic substances, 85% of this solution is water, 10% is proteins and 5% is other compounds. | containing genetic information (DNA molecules), performing the main functions: storage, transmission and implementation of hereditary information with the provision of protein synthesis. | Present, cell wall elastic, glycalix | No. |
4. Formulate a conclusion.
Output: _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, a vacuole and plastids; animals, unlike plants, have a thin glycogen membrane (performs pinocytosis, endocytosis, exocytosis, phagocytosis), and there are no vacuoles (except for protozoa).
Lab #2
Question 28. Food chain. Types of food chains.
FOOD CHAIN(trophic chain, food chain), the relationship of organisms through the relationship of food - consumer (some serve as food for others). In this case, the transformation of matter and energy from producers(primary producers) through consumers(consumers) to decomposers(converters of dead organics into inorganic substances digestible by producers). There are 2 types of food chains - pasture and detrital. The pasture chain begins with green plants, goes to grazing herbivorous animals (consumers of the 1st order) and then to predators that prey on these animals (depending on the place in the chain - consumers of the 2nd and subsequent orders). The detrital chain starts with detritus (a product of the decomposition of organic matter), goes to microorganisms that feed on it, and then to detritus feeders (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 savannah. Primary producers are herbage and trees, consumers of the 1st order are herbivorous insects and herbivores (ungulates, elephants, rhinos, 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 pasture chain destroy the carcasses of dead animals and the remains of predators' food. The number of individuals included in the food chain consistently decreases in each of its links (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 each other, but are intertwined with each other, forming 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 proposed in 1927 to schematically depict these relationships.
In a schematic representation, each level is shown as a rectangle, the length or area of \u200b\u200bwhich corresponds to the numerical values \u200b\u200bof the food chain link (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, the 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, for all the pyramids, the basic rule is established, 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 plant and animal species in natural and artificially created ecological systems. For example, 1 kg of the mass of a sea animal (seal, dolphin) needs 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 stable.
However, as you know, there are exceptions to every rule, which will be considered in each type of ecological pyramids.
The first ecological schemes in the form of pyramids were built in the twenties of the XX century. Charles Elton. They were based on field observations of a number of animals of various size classes. Elton did not include primary producers in them and did not make any distinction between detritophages and decomposers. However, he noted that predators are usually larger than their prey, and realized that such a ratio is extremely specific only for certain size classes of animals. In the 1940s, the American ecologist Raymond Lindeman applied Elton's idea to trophic levels, abstracting away from the specific organisms that make them up. However, if it is easy to distribute animals into size classes, then determining which trophic level they belong to is much more difficult. In any case, this can only be done in a very simplified and generalized way. Nutritional ratios and the efficiency of energy transfer in the biotic component of an ecosystem are traditionally depicted as 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 of each trophic level; 2) biomass pyramids, which use the total mass (usually dry) of organisms at each trophic level; 3) pyramids of energy, taking into account the energy intensity of organisms of each trophic level.
Types of ecological pyramids
pyramids of numbers- at each level, the number of individual organisms is postponed
The pyramid of numbers reflects a clear pattern discovered by Elton: the number of individuals that make up a sequential series of links from producers to consumers is steadily decreasing (Fig. 3).
For example, to feed one wolf, you need at least a few hares that he could hunt; to feed these hares, you need a fairly large number of various plants. In this case, the pyramid will look like a triangle with a wide base tapering upwards.
However, this form of a pyramid of numbers is not typical for all ecosystems. Sometimes they can be reversed, or inverted. This applies to forest food chains, when trees serve as producers, and insects 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), so 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 / m 2, kg / ha, t / km 2 or per volume - g / m 3 (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 second-order consumers, and so on.
In this case (if the organisms do not differ too much in size), the pyramid will also look like a triangle with a wide base tapering upwards. 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, which is represented mainly by unicellular algae. This is explained by the fact that algae are very quickly eaten away by zooplankton, but the very high rate of division of their cells protects them from complete eating.
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 biomass pyramid can be reversed or inverted (pointed downwards). So, in lakes and seas, the mass of plants exceeds the mass of consumers only during the flowering period (spring), and in the rest of the year the situation may be reversed.
Pyramids of numbers and biomass reflect the statics of the system, i.e., 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 the ecosystem, although they allow solving a number of practical problems, especially those related to maintaining the stability of ecosystems.
The pyramid of numbers makes it possible, for example, to calculate the allowable value of catching fish or shooting animals during the hunting period without consequences for their normal reproduction.
energy pyramids- shows the magnitude of the 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 a mass of food (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 intensity of metabolism of individuals, and if all sources of energy are taken into account, then the pyramid will always have a typical appearance with a wide base and a tapering top. When building a pyramid of energy, a rectangle is often added to its base, showing the influx of solar energy.
In 1942, the American ecologist R. Lindeman formulated the law of the pyramid of energies (the law of 10 percent), according to which, on average, about 10% of the energy received by 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. Organisms, as a result of metabolic processes, lose about 90% of all the energy that is expended to maintain their vital activity in each link of the food chain.
If a hare ate 10 kg of plant matter, then its own weight could increase by 1 kg. A fox or a wolf, eating 1 kg of hare, 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 algae, this value is much higher, since they do not have hard-to-digest tissues. However, the general regularity of the process of energy transfer remains: much less energy passes through the upper trophic levels than through the lower ones.
For me, nature is a kind of well-oiled mechanism, in which everything is provided for to the smallest detail. It's amazing how everything is thought out, and it is unlikely that a person will ever be able to create something like this.
What does the term food chain mean?
According to the scientific definition, this concept includes the transfer of energy through a number of organisms, where the first link is the producers. This group includes plants that absorb inorganic substances, from which they synthesize nutritious organic compounds. Consumers feed on them - such organisms that are not capable of independent synthesis, which means that they are forced to eat ready-made organic matter. These are herbivores and insects, which act as a "lunch" for other consumers - predators. As a rule, the chain contains about 4-6 levels, where the closing link is represented by decomposers - organisms that decompose organic matter. In principle, there can be much more links, but there is a natural "limiter": on average, each link receives little energy from the previous one - up to 10%.
Examples of food chains in a forest community
Forests have their own characteristics, depending on their type. Coniferous forests do not have rich herbaceous vegetation, which means that food chains will have a certain set of animals. For example, a deer enjoys eating elderberry, and he himself becomes the prey of a bear or lynx. For a broad-leaved forest there will be a set. For example:
- bark - bark beetles - titmouse - falcon;
- fly - reptile - ferret - fox;
- seeds and fruits - squirrel - owl;
- plant - beetle - frog - already - hawk.
It is worth mentioning the scavengers who "recycle" organic remains. There are a great many of them in the forests: from the simplest unicellular to vertebrates. Their contribution to nature is enormous, because, otherwise, the planet would be covered with the remains of animals. They also convert dead bodies into inorganic compounds that plants need, and everything starts anew. In general, nature is perfection itself!
