All-Russian Olympiad for Schoolchildren in Ecology
School stage. 6th grade.
Task No. 1. Each correct answer is worth 1 point. Maximum - 10 points.
Choose one correct answer from the given options:
- An individual is:
a) biological species
b) a single living organism
c) animal community
d) family of living organisms
2. Ecology translated from Greek words means:
A. warmth, light;
B. plants, animals;
V. house, dwelling.
D) environmental protection
3. Birds mark their territories:
a) excrement
b) sounds
c) feathers
d) nests
- The main component of the ecosystem that creates organic matter:
a) plants
b) bacteria
c) mushrooms
d) animals
- Phytocenosis is:
A) different types animals
b) different types of plants
c) different types of bacteria
d) different types of mushrooms
6. Habitat is:
A. predators that influence organisms.
B. only light that affects organisms;
B. only water that affects organisms;
G. alive and inanimate nature affecting organisms;
- Autotrophs are:
a) bacteria
b) plants
c) insects
- The phenomenon of starvation, i.e. mass death fish, is called:
a) lack of food
b) lack of oxygen
c) lack of light
9. What features are not typical for the inhabitants of the soil environment:
A. presence of gills;
B. skin respiration;
B. elongated body;
G. burrowing limbs
10. What is the name of the profession of a person who works with animals in nature reserves??
a) huntsman;
b) forester;
c) poacher.
d) observer
Task No. 2. Each correct answer is worth 0.5 points. Maximum - 12.5 points.
Choose several correct answers (from one to five) from the given options:
1. The plant organism is affected by:
A. other plants;
B. animals;
B. inanimate nature;
G. person.
D. bacteria and fungi
2. What types of plants predominate in the coniferous forest:
A. birch;
B. aspen;
V. pine;
G. willows.
Delhi
E. larch
3. Among fish, those with caviar are characterized by low fertility:
A) It is large in size.
B) Guarded by the female.
B) Floats in the water column.
D) Buries itself in the sand.
d) is small in size
4. Which measures are most effective in protecting rare species animals and plants:
a) Protection of each individual individually.
b) Protection of habitats.
c) Protection of breeding sites.
d) Protection of food resources of these species.
e) Growing under artificial conditions.
5. Examples of competition are the relationships between:
a) Predators and prey.
c) Species that use the same resources.
d) Individuals of the same species.
e) symbiotic organisms
Task No. 3. Each correct answer is worth 1 point.
Maximum - 10 points.
Choose the correct judgments:
- The life of organisms outside their habitat is impossible.
- Weeds are less hardy than cultivated plants.
- Species living in strictly defined conditions have broad ecological adaptability.
- Plants of different life forms form tiers.
- Human activity does not affect the living conditions of plants.
- Plants grow throughout their lives.
- Plants short day- people from the northern regions.
- Light is absorbed by the green pigment - chlorophyll.
- Plants need oxygen for respiration.
- Loosening the soil does not affect soil inhabitants.
Task No. 4
Answers to tasks of the All-Russian Olympiad for schoolchildren in ecology
School stage. 6th grade.
Task No. 1.
1-b, 2-c, 3-b, 4-a, 5-b, 6-d, 7-b, 8-b, 9-a, 10-a.
Task No. 2.
1-a, b, c, d, e.
2-c, d, f.
3-a, b.
4-c, d.
5-c, g.
Task No. 3.
1,4, 6, 8, 9.
Task No. 4.
Why are green plants called the “lungs of the planet”? (3 points).
ANSWER: During photosynthesis, plants absorb carbon dioxide and release oxygen. All living organisms use oxygen when breathing. Like lungs, green plants provide all organisms on the planet with the oxygen they need for their life.
There is an opinion that forests are the “lungs of the planet”, since it is believed that they are the main suppliers of oxygen to the atmosphere. However, in reality this is not the case. The main producers of oxygen live in the ocean. These babies cannot be seen without the help of a microscope. But all living organisms on Earth depend on their livelihoods.
No one argues that forests, of course, need to be preserved and protected. However, not at all because they are these notorious “lungs”. Because in fact, their contribution to the enrichment of our atmosphere with oxygen is practically zero.
No one will deny the fact that the oxygen atmosphere of the Earth was created and continues to be maintained by plants. This happened because they learned to create organic substances from inorganic ones, using the energy of sunlight (as we remember from the school biology course, a similar process is called photosynthesis). As a result of this process, plant leaves release free oxygen as a by-product of production. This gas, which we need, rises into the atmosphere and is then evenly distributed throughout it.
According to various institutes, thus, about 145 billion tons of oxygen are released into the atmosphere on our planet every year. Moreover, most of it is spent, not surprisingly, not on the respiration of the inhabitants of our planet, but on the decomposition of dead organisms or, simply put, on decay (about 60 percent of that used by living beings). So, as you can see, oxygen not only gives us the opportunity to breathe deeply, but also acts as a kind of stove for burning garbage.
As we know, any tree is not eternal, so when the time comes, it dies. When the trunk of a forest giant falls to the ground, its body is decomposed by thousands of fungi and bacteria over a very long period of time. All of them use oxygen, which is produced by surviving plants. According to researchers' calculations, such “cleaning up the territory” consumes about eighty percent of the “forest” oxygen.
But the remaining 20 percent of oxygen does not enter the “general atmospheric fund” at all, and is also used by forest inhabitants “on the ground” for their own purposes. After all, animals, plants, fungi and microorganisms also need to breathe (without oxygen, as we remember, many living beings would not be able to obtain energy from food). Since all forests are usually very densely populated areas, this residue is only enough to satisfy the oxygen needs of only its own inhabitants. There is nothing left for neighbors (for example, residents of cities where there is little native vegetation).
Who, then, is the main supplier of this gas necessary for breathing on our planet? On land these are, oddly enough... peat bogs. Everyone knows that when plants die in a swamp, their organisms do not decompose, since the bacteria and fungi that do this work cannot live in swamp water - there are many natural antiseptics secreted by mosses.
So, dead parts of plants, without decomposing, sink to the bottom, forming peat deposits. And if there is no decomposition, then oxygen is not wasted. Therefore, swamps contribute about 50 percent of the oxygen they produce to the general fund (the other half is used by the inhabitants of these inhospitable, but very useful places).
Nevertheless, the contribution of swamps to the total " charitable foundation oxygen" is not very large, because there are not so many of them on Earth. Microscopic ocean algae, the totality of which scientists call phytoplankton, are much more actively involved in “oxygen charity”. These creatures are so small that it is almost impossible to see them with the naked eye. However, their total very large, the number goes into millions of billions.
The entire world's phytoplankton produces 10 times more oxygen than it needs for breathing. Enough to provide useful gas to all other inhabitants of the waters, and quite a lot gets into the atmosphere. As for the oxygen consumption for the decomposition of corpses, in the ocean they are very low - approximately 20 percent of the total production.
This happens due to the fact that dead organisms are immediately eaten by scavengers, which sea water a great multitude live. Those, in turn, will be eaten by other scavengers after death, and so on, that is, corpses almost never lie in the water. The same remains, which are no longer of particular interest to anyone, fall to the bottom, where few people live, and there is simply no one to decompose them (this is how the well-known silt is formed), that is, in this case, oxygen is not consumed.
So, the ocean supplies the atmosphere with about 40 percent of the oxygen that phytoplankton produced. It is this reserve that is consumed in those areas where very little oxygen is produced. The latter, in addition to cities and villages, include deserts, steppes and meadows, as well as mountains.
So, oddly enough, the human race lives and thrives on Earth precisely due to the microscopic “oxygen factories” floating on the surface of the ocean. It is they who should be called “the lungs of the planet.” And protect in every possible way from oil pollution, heavy metal poisoning, etc., because if they suddenly stop their activities, you and I will simply have nothing to breathe.
There is a journalistic cliche that forests are the lungs of planet Earth. But what then to do with the data of science, which suggests that the oxygen atmosphere arose on our planet long before photosynthesis?
In fact, plants of both land and oceans produce approximately as much oxygen through the process of photosynthesis as they then consume during respiration.
Initially, the Earth's atmosphere was generally reducing in nature: methane + ammonia + water + carbon dioxide.
The earth's crust should also have had a restorative character - after all, it was in equilibrium with the atmosphere.
And today we have that the atmosphere contains 20% free oxygen, and most rocks are completely oxidized and the system is in a state of equilibrium (the composition of the atmosphere has not changed significantly for several hundred million years).
In order to oxidize the entire primary atmosphere and lithosphere, a huge amount of free oxygen is needed.
The balances don't add up
According to the generally accepted hypothesis, it is believed that living organisms are responsible for the release of oxygen.
But they are not suitable for this role, since despite the fact that plants release a significant amount of oxygen per unit time, in general the biosphere is quite stable - the circulation of substances occurs in it. The release of free oxygen can only be achieved through the accumulation of undecomposed residues (mainly in the form of coal). In other words:
H2O + CO2 = biomass (C + O + H) + O2 + C + CH4.
Considering that the current biomass is small compared to the mass of even free oxygen in the atmosphere (it is approximately one hundred times less), we obtain that in order for all the atmospheric and lithospheric (for the oxidation of the primary lithosphere) oxygen to be formed, it is necessary to store it somewhere in the Earth there would be similar mass reserves of coal and hydrocarbons - and this is a layer of several meters only for atmospheric oxygen, and for lithospheric oxygen it is orders of magnitude larger. No such reserves are observed (estimated reserves of coal and other hydrocarbons approximately correspond to the total biomass).
So, our balance sheets clearly don’t add up.
In the bright sun
Note that another source of oxygen is the dissociation of water molecules under the influence of solar radiation.
As is known, the speed of molecules in a gas obeys the Maxwell distribution. According to this distribution, there is always a certain proportion of molecules whose speed exceeds the second cosmic speed. And such molecules can leave the Earth freely. Moreover, light gases—hydrogen and helium—are the first to escape from the atmosphere. Calculations show that the time for complete evaporation of hydrogen from the earth's atmosphere is only a few years. But hydrogen is still present in the atmosphere. Why? For oxygen and other gases, this time exceeds the lifetime of the Earth. million years. In the earth's atmosphere, hydrogen and helium are constantly renewed due to supply from the earth's interior and a number of atmospheric processes. The hydrogen that forms the “corona” around the Earth is a product of the dissociation of water molecules under the influence of ultraviolet and X-ray radiation from the Sun.
Calculations show that over a period of about ten million years, an amount of oxygen equal to the current value appears in the atmosphere due to photodissociation.
So we get:
1) Initially, the atmosphere, lithosphere and entire mantle of the Earth are of a reducing nature.
2) Due to photodissociation, water (which, by the way, came from the mantle as a result of volcanic activity) decomposes into oxygen and hydrogen. The latter leaves the Earth.
3) The remaining oxygen oxidizes the primary lithosphere and atmosphere to its current state.
4) Why does oxygen not accumulate, since it is constantly supplied as a result of photodissociation (the current amount accumulates in 10 million years, and the age of the Earth is 4.5 billion)? It goes towards oxidation of the mantle. As a result of the movement of continents in subduction zones, new crust is formed from the mantle. The rocks of this crust are oxidized under the influence of the atmosphere and hydrosphere. These oxidized rocks from oceanic plates at subduction zones are then released back into the mantle.
Statistics of the universe
Well, what about living organisms, you ask? They actually play the role of extras - there was no free oxygen, they lived without it - at the primitive single-cell level. It appeared - they adapted and began to live with it - but in the form of advanced multicellular organisms.
So whether there are forests on Earth or not, this will not affect the oxygen content in the planet’s atmosphere. Another thing is that the forest clears the air of dust, saturates it with phytoncides, provides shelter and food for many animals and birds, and gives people aesthetic pleasure... But calling the forest “green lungs” is, at the very least, illiterate.
Yes, I definitely remember from school that forests are the lungs of the planet. There were such posters. They constantly said that the forest must be protected, it produces the oxygen that we breathe. Where are we without oxygen? Nowhere. That's why they compare forested areas with the lungs of our planet Earth.
And what? Isn't that right?
Yes, not like that. The functions of forests are more reminiscent of the work of the liver and kidneys. Forests provide as much oxygen as they consume. But they cope with the task of cleaning the air and protecting the soil from erosion like no one else.
So what can be called “the lungs of the planet”?
In fact, oxygen is produced not only by those plants that grow in the forest. All plant organisms, including inhabitants of reservoirs, and inhabitants of steppes and deserts, constantly produce oxygen. Plants, unlike animals, fungi and other living organisms, can synthesize organic substances themselves, using light energy for this. This process is called photosynthesis. As a result of photosynthesis, oxygen is released. It is a by-product of photosynthesis. A lot of oxygen is released, in fact, 99% of the oxygen that is present in the Earth’s atmosphere plant origin. And only 1% comes from the mantle, the underlying layer of the Earth.
Of course, trees produce oxygen, but no one thinks about the fact that they also waste it. And not only them, all other inhabitants of the forest cannot be without oxygen. First of all, plants respire on their own, this happens in the dark when photosynthesis does not occur. And we need to somehow utilize the reserves of organic substances that they created during the day. That is, feed yourself. And in order to eat you need to spend oxygen. Another thing is that plants spend much less oxygen than they produce. And this is ten times less. However, we should not forget that in the forest there are still animals, as well as mushrooms, as well as various bacteria that do not produce oxygen themselves, but nevertheless breathe it. Significant amount The oxygen that the forest produced during daylight hours will be used by living organisms of the forest to support life. However, something will remain. And this is something like 60% of what the forest produces. This oxygen enters the atmosphere, but does not remain there for very long. Then the forest itself removes oxygen, again for its own needs. Namely, the decomposition of the remains of dead organisms. Ultimately, forests often spend 1.5 times more oxygen to dispose of their own waste than they produce. After this, it cannot be called the oxygen factory of the planet. True, there are forest communities that operate on a zero oxygen balance. These are famous rainforests.
The tropical forest is generally a unique ecosystem; it is very stable, because the consumption of substances is equal to production. But again, there was no surplus left. So even tropical forests can hardly be called oxygen factories.
So why then, after the city, does it seem to us that there is clean, fresh air in the forest, that there is a lot of oxygen there? The thing is that oxygen production is a very fast process, but consumption is a very slow process.
So what then are the oxygen factories of the planet? There are actually two ecosystems. Among the “land” ones are peat bogs. As we know, in a swamp the process of decomposition of dead matter is very, very slow, as a result of which dead parts of plants fall down, accumulate, and peat deposits are formed. Peat does not decompose, it is compressed and remains in the form of a huge organic brick. That is, during peat formation, a lot of oxygen is not wasted. Thus, swamp vegetation produces oxygen, but consumes very little oxygen itself. As a result, it is the swamps that provide exactly the increase that remains in the atmosphere. However, real peat bogs there are not so many on land, and of course it is almost impossible for them alone to maintain the oxygen balance in the atmosphere. And here another ecosystem helps, called the world ocean.
There are no trees in the world's oceans; grasses in the form of algae are observed only near the coast. However, vegetation still exists in the ocean. And most of it consists of microscopic photosynthetic algae, which scientists call phytoplankton. These algae are so small that it is often impossible to see each of them with the naked eye. But the accumulation of them is visible to everyone. When bright red or bright green spots are visible on the sea. This is phytoplankton.
Each of these little algae produces enormous amounts of oxygen. It consumes very little itself. Due to the fact that they rapidly divide, the amount of oxygen they produce increases. One phytoplankton community produces 100 times more per day than a forest occupying the same volume. But at the same time they spend very little oxygen. Because when algae die, they immediately fall to the bottom, where they are immediately eaten. After that, those who ate them are eaten by other, third organisms. And so few remains reach the bottom that they quickly decompose. There is simply no decomposition that lasts as long as in the forest, in the ocean. There, recycling occurs very quickly, as a result of which oxygen is virtually not wasted. And so the “big profit” occurs, and so it remains in the atmosphere.
sources
The world of flora is diverse. We are surrounded by flowers, shrubs, trees, grasses of many shades, but the predominant color scheme is green. But why are plants green?
Reasons for green color
Plants are rightly called the lungs of the planet. By processing harmful carbon dioxide, they give humanity and environment oxygen. This process is called photosynthesis, and the pigment responsible for it is chlorophyll.
Thanks to chlorophyll molecules inorganic substances become organic. The most important of them is oxygen, but at the same time, during the process of photosynthesis, plants produce proteins, sugar, carbohydrates, fats, and starch.
Co school curriculum It is known that the beginning of a chemical reaction is when the plant gets exposed to sunlight or artificial light. Chlorophyll absorbs not all light waves, but only a certain wavelength. This occurs most quickly from red to blue-violet.
Green is not absorbed by plants, but is reflected. This is what is visible to the human eye, therefore, representatives of the flora around us have green color.
Why green?
Enough long time Scientists have struggled with the question: why is the green spectrum reflected? As a result, it turned out that nature simply does not waste energy in vain, because these tiny particles of light - photos of this color do not have any outstanding qualities, while blue photons are sources of useful energy, red ones contain greatest number. How can one not remember that nothing in nature is done just like that.
Where do bright colors come from in plants?
Biologists say with confidence that plants originated from something similar to algae, and chlorophyll appeared under the influence of evolutionary processes.
In nature, other colors change under the influence of light. When it becomes smaller, the leaves and stems begin to die off. Chlorophyll, which is responsible for the bright green color, breaks down. It is replaced by other pigments responsible for bright colors. Red and yellow leaves indicate that carotene has become predominant. Behind yellow The pigment xanthosine is also responsible. If green color cannot be found in a plant, it is the “fault” of anthocyanins.
Works of scientists on photosynthesis and chlorophyll
How was photosynthesis discovered?
The discovery of the process of converting carbon dioxide into oxygen happened by accident and was made by the English chemist Joseph Priestley. The scientist was looking for a way to purify “spoiled air” (as carbon dioxide was called at that time). And during the experiments, a plant was placed under a glass bell, instead of a mouse and a candle, which, contrary to expectations, survived. The next step was to place a mouse next to the flower in the pot. And a miracle happened - the animal did not die from suffocation. Thus, the conclusion was made about the possibility of converting carbon dioxide into oxygen.
The Russian naturalist Kliment Arkadyevich Timiryazev devoted much attention and a lot of time to the role of chlorophyll and the process of photosynthesis. His main scientific achievements:
- proof of the extension of the law of conservation of energy to the process of photosynthesis, which was denied by Western researchers;
- establishing the fact that only light rays absorbed by the plant participate in photosynthesis.
Works by K.A. Timiryazev laid a solid foundation for the doctrine of the transformation of water and carbon dioxide into organic useful substances under the influence of light. Now science has stepped far forward, some studies have undergone changes (for example, the fact that a light beam decomposes not carbon dioxide, but water), but we can say with confidence that it was they who studied the basics. The book “The Life of a Plant” will allow you to get acquainted with the work of a scientist - it’s fascinating and educational facts about the nutrition, growth, development and reproduction of green plants.
Photosynthesis and chlorophyll are closely related when it comes to why plants are green. The light beam has several spectra, some of which are absorbed and participate in the chemical process of converting carbon dioxide into oxygen. Green is reflected and gives its color to the leaves and stems - and this is visible to the human eye.
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