Bacteria capable of binding as a result of their vital activity. Bacteria. How do bacteria feed?

Introduction.

1. The structure and activity of bacteria.

   Sensory functions and behavior.

   Reproduction and genetics.

   Metabolism.

2. Main sources of energy.

3. Classification.

   Ecology.

   Bacteria in industry.

   Diseases from bacteria.

Introduction

Bacteria - a large group of unicellular microorganisms characterized by the absence of a cell nucleus surrounded by a membrane. At the same time, the genetic material of the bacterium (deoxyribonucleic acid, or DNA) occupies a very specific place in the cell - a zone called the nucleoid. Organisms with such a cell structure are called prokaryotes (“pre-nuclear”), in contrast to all others - eukaryotes (“truly nuclear”), whose DNA is located in a nucleus surrounded by a shell.

Bacteria, previously considered microscopic plants, are now separated into an independent kingdom Monera- one of five in the current classification system along with plants, animals, fungi and protists.

Story

Bacteria are probably the oldest known group of organisms. Layered stone structures - stromatolites - dated in some cases to the beginning of the Archeozoic (Archean), i.e. arose 3.5 billion years ago, is the result of the vital activity of bacteria, usually photosynthesizing, the so-called. blue-green algae. Similar structures (bacterial films impregnated with carbonates) are still formed now, mainly off the coast of Australia, the Bahamas, in the California and Persian Gulfs, but they are relatively rare and do not reach large sizes, because herbivorous organisms feed on them, for example gastropods. Nowadays, stromatolites grow mainly where these animals are absent due to high salinity of water or for other reasons, but before the emergence of herbivorous forms during the evolution, they could reach enormous sizes, constituting an essential element of oceanic shallow water, comparable to modern coral reefs. In some ancient rocks, tiny charred spheres have been found, which are also believed to be the remains of bacteria. The first nuclear ones, i.e. eukaryotic, cells evolved from bacteria approximately 1.4 billion years ago.

The structure and activity of bacteria

Bacteria are much smaller than the cells of multicellular plants and animals. Their thickness is usually 0.5–2.0 µm, and their length is 1.0–8.0 µm. Some forms are barely visible at the resolution of standard light microscopes (approximately 0.3 microns), but species are also known with a length of more than 10 microns and a width that also goes beyond the specified limits, and a number of very thin bacteria can exceed 50 microns in length. On the surface corresponding to the point marked with a pencil, a quarter of a million medium-sized representatives of this kingdom will fit.

Based on their morphological features, the following groups of bacteria are distinguished: cocci (more or less spherical), bacilli (rods or cylinders with rounded ends), spirilla (rigid spirals) and spirochetes (thin and flexible hair-like forms). Some authors tend to combine the last two groups into one - spirilla. Prokaryotes differ from eukaryotes mainly in the absence of a formed nucleus and the typical presence of only one chromosome - a very long circular DNA molecule attached at one point to the cell membrane. Prokaryotes also do not have membrane-enclosed intracellular organelles called mitochondria and chloroplasts. In eukaryotes, mitochondria produce energy during respiration, and photosynthesis occurs in chloroplasts. In prokaryotes, the entire cell (and primarily the cell membrane) takes on the function of a mitochondrion, and in photosynthetic forms, it also takes on the function of a chloroplast. Like eukaryotes, inside bacteria there are small nucleoprotein structures - ribosomes, necessary for protein synthesis, but they are not associated with any membranes. With very few exceptions, bacteria are unable to synthesize sterols, important components of eukaryotic cell membranes.

Outside the cell membrane, most bacteria are covered with a cell wall, somewhat reminiscent of the cellulose wall of plant cells, but consisting of other polymers (they include not only carbohydrates, but also amino acids and bacteria-specific substances). This membrane prevents the bacterial cell from bursting when water enters it through osmosis. On top of the cell wall is often a protective mucous capsule. Many bacteria are equipped with flagella, with which they actively swim. Bacterial flagella are structured simpler and somewhat differently than similar structures of eukaryotes.

Figure 1 – Structure of a typical bacterial cell

People are trying to find new ways to protect themselves from their harmful influence. But there are also beneficial microorganisms: they promote the ripening of cream, the formation of nitrates for plants, decompose dead tissue, etc. Microorganisms live in water, soil, air, on the body of living organisms and inside them.

Shapes of bacteria

There are main 4 forms of bacteria, namely:

1. Micrococci – located separately or in irregular clusters. They are usually motionless.
2. Diplococci are arranged in pairs and can be surrounded by a capsule in the body.
3. Streptococci occur in the form of chains.
4. Sarcines form clusters of cells shaped like packets.
5. Staphylococci. As a result of the division process, they do not diverge, but form clusters (clusters).

The bacterium has a complex structure:

• Wall cells protect a single-celled organism from external influences, give it a certain shape, provide nutrition and preserve its internal contents.
• Cytoplasmic membrane contains enzymes, participates in the process of reproduction and biosynthesis of components.
• Cytoplasm serves to perform vital functions. In many species, the cytoplasm contains DNA, ribosomes, various granules, and a colloidal phase.
• Nucleoid is the irregularly shaped nuclear region in which DNA is located.
• Capsule is a surface structure that makes the shell more durable and protects against damage and drying out. This mucous structure has a thickness of more than 0.2 microns. With a smaller thickness it is called microcapsule. Sometimes around the shell there is slime, has no clear boundaries and is soluble in water.
• flagella are called surface structures that serve to move cells in a liquid environment or on a solid surface.
• Drank- thread-like formations, much thinner and fewer flagella. They come in various types, differ in purpose and structure. Pili are needed to attach the organism to the affected cell.
• Controversy. Sporulation occurs when unfavorable conditions arise and serves to adapt the species or preserve it.

We suggest considering the main types of bacteria:

Nutrients enter the cell through its entire surface. Microorganisms have become widespread due to the existence of different types of nutrition. To live, they need a variety of elements: carbon, phosphorus, nitrogen, etc. The supply of nutrients is regulated using a membrane.

The type of nutrition is determined by how carbon and nitrogen are absorbed and by the type of energy source. Some of them can obtain these elements from the air and use solar energy, while others require substances of organic origin to exist. They all need vitamins and amino acids that can act as catalysts for reactions occurring in their body. The removal of substances from the cell occurs through the process of diffusion.

In many types of microorganisms, oxygen plays an important role in metabolism and respiration. As a result of respiration, energy is released, which they use to form organic compounds. But there are bacteria for which oxygen is lethal.

Reproduction occurs by dividing the cell into two parts. After it reaches a certain size, the separation process begins. The cell elongates and a transverse septum is formed in it. The resulting parts disperse, but some species remain connected and form clusters. Each of the newly formed parts feeds and grows as an independent organism. When placed in a favorable environment, the reproduction process occurs at high speed.

Microorganisms are able to decompose complex substances into simple ones, which can then be used again by plants. Therefore, bacteria are indispensable in the cycle of substances; without them, many important processes on Earth would be impossible.

Do you know?

Conclusion: Don't forget to wash your hands every time you come home after going outside. When you go to the toilet, also wash your hands with soap. A simple rule, but so important! Keep it clean and bacteria won't bother you!

To reinforce the material, we invite you to complete our exciting assignments. Good luck!

Task No. 1

Look carefully at the picture and tell me which of these cells is bacterial? Try to name the remaining cells without looking at the clues:

The soils that are present on Earth today were formed as a result of the activity of bacteria. By processing mineral particles of rocks and mixing them with the products of processing dead organic compounds and the result of their own vital activity, microorganisms gradually turned the lifeless rocky valleys of our planet into fertile lands. Living microorganisms and bacteria are the most important element of the natural cycle chain in nature. It is believed that they are the engine of this process.

There are a lot of them in nature: just one gram of forest soil contains tens and even hundreds of millions of soil bacteria of different species and subspecies.

Natural cycle

During the growth process, plants reproduce complex organic substances from simple substances: water, mineral salts and carbon dioxide. Microorganisms living in the soil, as a result of their vital activity, process dead parts of plants and dead organisms into humus, thereby decomposing complex substances into simple ones. Plants can use these components again for their development and growth.

Distribution of soil microorganisms

There are a great many bacteria around us and they are distributed almost everywhere. They are not found except in the craters of active volcanoes and in small areas of test sites where explosions of atomic weapons are carried out. No other harsh environmental conditions interfere with the existence of bacteria. They calmly endure the glaciers of the Antarctic and live in the water of scalding boiling springs, calmly adapt to the hot sands of hot deserts and live on the rocky slopes of mountain peaks. There are so many of them that it is quite possible that we don’t even know some of the names of soil bacteria. On Earth, all living beings constantly interact with microflora, often playing the role of its guardian and distributor.

The soil microflora is very rich and diverse. Up to a billion bacteria can be found in just one cubic centimeter. However, the population of soil microorganisms can change. This depends on the type and composition of the soil, its condition, as well as the depth of the layer being studied.

How do bacteria feed?

Soil microorganisms can obtain energy in several ways. Some of the bacteria in this group are autotrophic, that is, they can independently produce their own substances for nutrition, and some of them use organic compounds as food. It is the last group, representing heterotrophic bacteria, that deserves special attention. Among the heterotrophic representatives of the kingdom of microorganisms, three main groups of bacteria are distinguished:

Each of these categories not only has a different way of eating, but also a completely different lifestyle. Some species can only exist in an airy or fermented milk environment, some microorganisms need the process of rotting and decomposition to fully exist, and some representatives can feel great in an airless space. Such bacteria can be found absolutely everywhere on our planet.

Soil bacteria

The habitat of such bacteria is soil. They are the smallest single-celled microorganisms. These creatures live in thin films of water in the soil around the root systems of various plants. Due to their small size, they can grow, develop and adapt to rapidly changing environmental conditions much faster than other larger and more complex microorganisms. The peculiarities of their shape allow these bacteria to perfectly adapt to their environment, so their structure has remained unchanged throughout the history of evolution. Typically, such microorganisms are spherical, rod-shaped, or have a curved geometry.

For the most part, soil bacteria are chemosynthetics, that is, they feed on products obtained as a result of redox reactions with the participation of carbon dioxide. In the process of their life activity, they produce substances necessary for the growth and development of other microorganisms.

The family of soil microorganisms is quite diverse. Bacteria present here are:

Nitrogen fixers

The unique ability of this group of soil bacteria is the ability to absorb nitrogen molecules from the air, which is impossible for plants. However, as a result of the synthesis produced by nitrogen fixers, nitrogen can be absorbed by plants. Based on their mode of existence, these bacteria are divided into free-living and symbionts, that is, those that need to interact with other microorganisms.

Nodule nitrogen fixers are symbionts that have an oblong oval or rod-shaped shape. They usually interact with legumes such as peas, lentils, alfalfa, etc.

Having settled in the root system, they form spherical nodules that are visible even to the naked eye, and live inside them. The symbiosis of bacteria and plants brings mutual benefits. This type of microorganism supplies nitrogen to the rhizomes, while the nutrition of soil bacteria occurs through the processing of products obtained directly from the plant and its dead particles. For many plants, nodule seals are the only source of nitrogen-containing compounds. However, in environments with a high nitrogen content, nodule microorganisms stop interacting with some plants. They are very selective and are activated only in certain types and varieties.

Today it is customary to divide nitrogen-fixing organisms into two groups. The first group is microbes that can enter into symbiosis with plants. These include species such as Rhizobium, Bradyrhizobium, Mezorhizobium, Sinorhizobium and Azorhizobium, which can live freely without interacting. The second group of soil associative nitrogen fixers are those more adapted to free existence in the soil. Examples of soil bacteria include Azospirillum, Pseudomonas, Agrobacterium, Klebsiella, Bacillus, Enterobacter, Flavobacterium Arthrobacter, Clostridium, Azotobacter, Beijerinckia and other genera.

Rotting bacteria

Saprophytes (rotting bacteria) usually live on the soil surface. They live in the upper layers of soil, on dead parts of plant root systems, and on the surface of dead larvae. They use organic dead tissue as a source of their vital activity: they are found in huge quantities on the remains of animals, fallen leaves and plant fruits. The result of their vital activity is the rapid decomposition and disposal of dead tissue. They significantly improve the composition of the soil, filling it with nutrients.

Most of the representatives of soil bacteria belong to the saprophyte family. There are two types of such microorganisms. Some of them live in oxygen-free environments, while others definitely need air for full life. These are free-living organisms that never enter into symbiosis.

Saprophytes are quite demanding when it comes to nutritional organic compounds. Any product they process must contain certain components, which affects the process of their growth, development and life. Essential nutritional compounds are:

• nitrogen-containing compounds or a certain set of amino acids;
• vitamins, protein and carbohydrate compounds;
• peptides, nucleotides.

How the process works

The decay of organic matter occurs due to the fact that microorganisms that contribute to the decomposition of matter have metabolism. As a result of this process, the chemical bonds of tissue molecules containing nitrogen compounds are destroyed. Nutrition of microorganisms is carried out due to the capture of elements containing protein and amino acids. As a result of fermentation of products entering the body of the bacteria, ammonia and hydrogen sulfide are released from protein compounds. In this way, microorganisms receive energy for their further existence.

In nature, decay bacteria play a primary role in soil restoration and mineralization. Hence the common name for bacteria of this type - decomposer. In the process of their life activity, decomposers convert organic substances and biomass into the simplest compounds CO 2, H 2 O, NH 3 and others. Among putrefactive bacteria, ammonifying microorganisms are widespread - non-spore-forming enterobacteria, bacilli, and spore-forming clostridia.

Fermentation bacteria

The way soil fermentation bacteria feed is through the processing of organic sugars. In the natural environment, they are usually found on the surface of plants, fruits and berries, in dairy products and in various layers of the epithelium of birds, animals, fish and humans. As a result of their vital activity, products sour with the formation of lactic acid. Due to this property, they are widely used in the preparation of all kinds of starters and fermented milk products. Lactic acid bacteria are also primary participants in the ensiling of plant feed for farm animals.

Soil lactic acid microorganisms predominantly have two forms - they can be elongated in the form of a stick or have a spherical shape.

Pathogenic bacteria

Putrefaction bacteria (saprophytes) and other opportunistic microbes that enter the human body from the environment can, under certain conditions, cause severe illness in both humans and animals. People with weakened immune systems and patients suffering from vitamin deficiency, neuroses and constant overwork are especially susceptible to this effect. There are cases when diseases caused by resident microflora are fatal.

Saprophytic microorganisms, having entered the human body, can cause bacterial shock, which develops as a result of the entry into the blood of a large number of conditionally pathogenic microorganisms and their metabolic products. Typically, this phenomenon occurs against the background of long-term focal infections.

Often, representatives of resident soil microflora contribute to the occurrence of purulent-inflammatory processes and abscesses in the body.

However, opportunistic microorganisms can have a negative impact on the body of living beings only when factors favorable to their vital activity appear. To improve soil soils, their enrichment and mineralization, such microflora is necessary. After all, without it, the lands will cease to be fertile at all, and this will undoubtedly become a negative factor for the natural cycle of life on Earth.

Fighting malicious guests

It is well known that saprophytes, once in food, cause spoilage. As a rule, such a process is accompanied by a large release of substances toxic to humans, hydrogen sulfide and ammonia. The substrate can heat up, sometimes to the point of spontaneous combustion. Therefore, man creates conditions in which microorganisms that cause rotting and decomposition lose their ability to reproduce or die altogether. Such measures include pasteurization, sterilization, salting, smoking, boiling, sugaring or drying of products.

Functions and importance of bacteria

Soil microorganisms contribute to the rapid decomposition of non-living organic matter, while forming high-quality humus in various layers of soil, necessary for the normal development of plants. Some bacteria are able to assimilate soil sources of nitrogen, phosphorus and iron. They can transform or redistribute metabolites between plant parts. Endorphytic microorganisms living in the inner layers of the root system of plants have a positive effect on their growth and development. This group of bacteria not only fights pathogenic microorganisms, but is even capable of producing vitamins and hormones for the plant. Therefore, the importance of soil microflora is difficult to overestimate.

Bacteria are the most ancient organism on earth, and also the simplest in their structure. It consists of just one cell, which can only be seen and studied under a microscope. A characteristic feature of bacteria is the absence of a nucleus, which is why bacteria are classified as prokaryotes.

Some species form small groups of cells; such clusters may be surrounded by a capsule (case). The size, shape and color of the bacterium are highly dependent on the environment.

Bacteria are distinguished by their shape into rod-shaped (bacillus), spherical (cocci) and convoluted (spirilla). There are also modified ones - cubic, C-shaped, star-shaped. Their sizes range from 1 to 10 microns. Certain types of bacteria can actively move using flagella. The latter are sometimes twice the size of the bacterium itself.

Types of forms of bacteria

To move, bacteria use flagella, the number of which varies—one, a pair, or a bundle of flagella. The location of the flagella can also be different - on one side of the cell, on the sides, or evenly distributed throughout the entire plane. Also, one of the methods of movement is considered to be sliding thanks to the mucus with which the prokaryote is covered. Most have vacuoles inside the cytoplasm. Adjusting the gas capacity of the vacuoles helps them move up or down in the liquid, as well as move through the air channels of the soil.

Scientists have discovered more than 10 thousand varieties of bacteria, but according to scientific researchers, there are more than a million species in the world. The general characteristics of bacteria make it possible to determine their role in the biosphere, as well as to study the structure, types and classification of the bacterial kingdom.

Habitats

Simplicity of structure and speed of adaptation to environmental conditions helped bacteria spread over a wide range of our planet. They exist everywhere: water, soil, air, living organisms - all this is the most acceptable habitat for prokaryotes.

Bacteria were found both at the south pole and in geysers. They are found on the ocean floor, as well as in the upper layers of the Earth's air envelope. Bacteria live everywhere, but their number depends on favorable conditions. For example, a large number of bacterial species live in open water bodies, as well as soil.

Structural features

A bacterial cell is distinguished not only by the fact that it does not have a nucleus, but also by the absence of mitochondria and plastids. The DNA of this prokaryote is located in a special nuclear zone and has the appearance of a nucleoid closed in a ring. In bacteria, the cell structure consists of a cell wall, capsule, capsule-like membrane, flagella, pili and cytoplasmic membrane. The internal structure is formed by cytoplasm, granules, mesosomes, ribosomes, plasmids, inclusions and nucleoid.

The cell wall of a bacterium performs the function of defense and support. Substances can flow freely through it due to permeability. This shell contains pectin and hemicellulose. Some bacteria secrete a special mucus that can help protect against drying out. Mucus forms a capsule - a polysaccharide in chemical composition. In this form, the bacterium can tolerate even very high temperatures. It also performs other functions, such as adhesion to any surfaces.

On the surface of the bacterial cell there are thin protein fibers called pili. There may be a large number of them. Pili help the cell pass on genetic material and also ensure adhesion to other cells.

Under the plane of the wall there is a three-layer cytoplasmic membrane. It guarantees the transport of substances and also plays a significant role in the formation of spores.

The cytoplasm of bacteria is 75 percent made from water. Composition of the cytoplasm:

• Fishsomes;
• mesosomes;
• amino acids;
• enzymes;
• pigments;
• sugar;
• granules and inclusions;
• nucleoid

Metabolism in prokaryotes is possible both with and without the participation of oxygen. Most of them feed on ready-made nutrients of organic origin. Very few species are capable of synthesizing organic substances from inorganic ones. These are blue-green bacteria and cyanobacteria, which played a significant role in the formation of the atmosphere and its saturation with oxygen.

Reproduction

In conditions favorable for reproduction, it is carried out by budding or vegetatively. Asexual reproduction occurs in the following sequence:

1. The bacterial cell reaches its maximum volume and contains the necessary supply of nutrients.
2. The cell lengthens and a septum appears in the middle.
3. Nucleotide division occurs inside the cell.
4. The main and separated DNA diverge.
5. The cell divides in half.
6. Residual formation of daughter cells.

With this method of reproduction, there is no exchange of genetic information, so all daughter cells will be an exact copy of the mother.

The process of bacterial reproduction under unfavorable conditions is more interesting. Scientists learned about the ability of sexual reproduction of bacteria relatively recently - in 1946. Bacteria do not have division into female and reproductive cells. But their DNA is heterogeneous. When two such cells approach each other, they form a channel for the transfer of DNA, and an exchange of sites occurs - recombination. The process is quite long, the result of which is two completely new individuals.

Most bacteria are very difficult to see under a microscope because they do not have their own color. Few varieties are purple or green in color due to their bacteriochlorophyll and bacteriopurpurin content. Although if we look at some colonies of bacteria, it becomes clear that they release colored substances into their environment and acquire a bright color. In order to study prokaryotes in more detail, they are stained.

Classification

Classification of bacteria can be based on indicators such as:

• Form
• way to travel;
• method of obtaining energy;
• waste products;
• degree of danger.

Bacteria symbionts live in community with other organisms.

Bacteria saprophytes live on already dead organisms, products and organic waste. They promote the processes of rotting and fermentation.

Rotting cleanses nature of corpses and other organic waste. Without the process of decay there would be no cycle of substances in nature. So what is the role of bacteria in the cycle of substances?

Rotting bacteria are an assistant in the process of breaking down protein compounds, as well as fats and other compounds containing nitrogen. After carrying out a complex chemical reaction, they break the bonds between the molecules of organic organisms and capture protein molecules and amino acids. When broken down, the molecules release ammonia, hydrogen sulfide and other harmful substances. They are poisonous and can cause poisoning in people and animals.

Rotting bacteria multiply quickly in conditions favorable to them. Since these are not only beneficial bacteria, but also harmful ones, in order to prevent premature rotting of products, people have learned to process them: drying, pickling, salting, smoking. All these processing methods kill bacteria and prevent them from multiplying.

Fermentation bacteria with the help of enzymes are able to break down carbohydrates. People noticed this ability back in ancient times and still use such bacteria to make lactic acid products, vinegars, and other food products.

Bacteria, working together with other organisms, do very important chemical work. It is very important to know what types of bacteria there are and what benefits or harm they bring to nature.

Meaning in nature and for humans

The great importance of many types of bacteria (in the processes of decay and various types of fermentation) has already been noted above, i.e. fulfilling a sanitary role on Earth.

Bacteria also play a huge role in the cycle of carbon, oxygen, hydrogen, nitrogen, phosphorus, sulfur, calcium and other elements. Many types of bacteria contribute to the active fixation of atmospheric nitrogen and convert it into organic form, helping to increase soil fertility. Of particular importance are those bacteria that decompose cellulose, which is the main source of carbon for the life of soil microorganisms.

Sulfate-reducing bacteria are involved in the formation of oil and hydrogen sulfide in medicinal mud, soils and seas. Thus, the layer of water saturated with hydrogen sulfide in the Black Sea is the result of the vital activity of sulfate-reducing bacteria. The activity of these bacteria in soils leads to the formation of soda and soda salinization of the soil. Sulfate-reducing bacteria convert nutrients in rice plantation soils into a form that becomes available to the roots of the crop. These bacteria can cause corrosion of metal underground and underwater structures.

Thanks to the vital activity of bacteria, the soil is freed from many products and harmful organisms and is saturated with valuable nutrients. Bactericidal preparations are successfully used to combat many types of insect pests (corn borer, etc.).

Many types of bacteria are used in various industries to produce acetone, ethyl and butyl alcohols, acetic acid, enzymes, hormones, vitamins, antibiotics, protein-vitamin preparations, etc.

Without bacteria, the processes of tanning leather, drying tobacco leaves, producing silk, rubber, processing cocoa, coffee, soaking hemp, flax and other bast-fiber plants, sauerkraut, wastewater treatment, leaching of metals, etc. are impossible.

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Biology, ME_MO–2012, 11th grade

Tasks
municipal stage of the XXVIII All-Russian Olympiad
schoolchildren in biology. Moscow region – 2011-12 school year. year

Grade 11

Part II. You are offered test tasks with one answer option out of four possible, but requiring preliminary multiple choice. The maximum number of points that can be scored is 30 (2 points for each test task). The index of the answer that you consider to be the most complete and correct, indicate in the answer matrix.

1. The following characteristics are common to fungi and plants:
   1) heterotrophy; 2) the presence of a well-defined cell wall, including chitin; 3) the presence of chloroplasts; 4) accumulation of glycogen as a reserve substance; 5) the ability to reproduce by spores.
   a) only 1;
   b) only 1, 2;
   c) only 1, 2, 5;
   d) only 1, 3, 4, 5;
   e) 1, 2, 3, 4, 5.
2. Lichens:
   1) can settle on bare rocks and are able to absorb moisture over the entire surface of the body;
   2) can be restored from part of the thallus;
   3) have a stem with leaves;
   4) with the help of adventitious filiform roots they are held on the rocks;
   5) are a symbiotic organism.
   a) only 1;
   b) only 1, 2;
   c) only 1, 2, 5;
   d) only 1, 3, 4, 5;
   e) 1, 2, 3, 4, 5.
3. The following organisms can produce silk-like threads:
   1) spiders; 2) ticks; 3) insects; 4) horseshoe crabs; 5) centipedes.
   a) 1, 2, 4;
   b) 1, 2, 3;
   c) 1, 3, 5;
   d) 1, 4, 5;
   e) 2, 3, 4.
4. It is known that in the process of making paint for dyeing fabric, people used animals: 1) insects; 2) echinoderms; 3) gastropods;
   4) cephalopods; 5) protozoa.
   a) 1, 3;
   b) 2, 5;
   c) 1, 3, 4;
   d) 3, 4, 5;
   e) 2, 3, 5.
5. Don't meet in fresh water bodies, representatives of the following groups of invertebrates: 1) sponges; 2) flatworms; 3) cephalopods; 4) echinoderms;
   5) annelids.
   a) 1, 2;
   b) 2, 5;
   c) 3, 4;
   d) 1, 4, 5;
   e) 2, 3, 4.
6. Insects with a front pair of wings not used for flight:
   1) earwigs; 2) dragonflies; 3) Hymenoptera; 4) dipterans; 5) Coleoptera.
   a) 1, 2;
   b) 2, 4;
   c) 1, 5;
   d) 1, 2, 5;
   e) 3, 4, 5.
7. The housefly's legs contain the following sensory organs:
   1) vision; 2) sense of smell; 3) touch; 4) taste; 5) hearing.
   a) 2, 3;
   b) 3, 4;
   c) 1, 4, 5;
   d) 2, 3, 5;
   e) 1, 2, 3, 4, 5.
8. Of the following organisms, the following overwinter in the zygote state:
   1) hydra
   2) crayfish
   3) daphnia
   4) dragonfly
   5) silver carp.
   a) 1, 2;
   b) 1, 3;
   c) 2, 4;
   d) 3, 5;
   e) 1, 3, 4.
9. A four-chambered heart is found in representatives of the following classes:
   1) bony fish; 2) amphibians, 3) reptiles; 4) birds; 5) mammals.
   a) 1, 2;
   b) 1, 2, 3;
   c) 2, 3;
   d) 2, 3, 4;
   e) 3, 4, 5.
10. To carry out blood clotting, the following substances are needed:
    1) potassium; 2) calcium; 3) prothrombin; 4) fibrinogen; 5) heparin.
    a) 1, 2, 3;
    b) 2, 3, 4;
    c) 2, 3, 5;
    d) 1, 3, 4;
    e) 2, 4, 5.
11. When you exhale calmly, air “leaves” the lungs because:
    1) the volume of the chest decreases;
    2) muscle fibers in the walls of the lungs contract;
    3) the diaphragm relaxes and protrudes into the chest cavity;
    4) the chest muscles relax;
    5) the chest muscles contract.
    a) 1, 2;
    b) 1, 3;
    c) 1, 3, 5;
    d) 1, 3, 4, 5;
    e) 1, 2, 3, 4, 5.
12. Of the listed substances, polymers are: 1) adenine; 2) cellulose;
    3) alanine; 4) thymine; d) insulin.
    a) 1, 2;
    b) 2, 3;
    c) 2, 5;
    d) 1, 3, 4;
    e) 2, 4, 5.
13. From the Golgi apparatus, proteins can enter: 1) into lysosomes; 2) in mitochondria;
    3) to the core; 4) on the outer membrane; 5) into the extracellular environment.
    a) 1, 2, 4;
    b) 1, 3, 5;
    c) 1, 4, 5;
    d) 1, 2, 4, 5;
    e) 1, 3, 4, 5.
14. RNA is found in:
    1) cytoplasmic membrane;
    2) smooth endoplasmic reticulum;
    3) rough endoplasmic reticulum;
    4) Golgi apparatus;
    5) core.
    a) 1, 2;
    b) 1, 3;
    c) 3, 4;
    d) 3, 5;
    e) 1, 3, 4.
15. Crossing over usually occurs in meiosis during conjugation:
    1) in men and women in any of 22 pairs of autosomes;
    2) in women in a pair of sex chromosomes; 3) in men in a pair of sex chromosomes;
    4) in chickens in a pair of sex chromosomes;
    5) in roosters in a pair of sex chromosomes.
    a) 1, 2, 4;
    b) 1, 3, 5;
    c) 1, 2, 5;
    d) 2, 4, 5;
    e) 3, 4, 5.

Part 3. You are offered test tasks in the form of judgments, with each of which you must either agree or reject. In the answer matrix, indicate the answer option “yes” or “no”. The maximum number of points that can be scored is 25 (1 point for each test task).

1. All ferns require water for fertilization.
2. The petiole performs the most important function - it orients the leaf blade relative to the light.
3. Photosynthesis is characteristic of all cells of green plants.
4. All protozoa have locomotor organs that ensure their activity.
5. Euglena green reproduces only vegetatively.
6. The circulatory system of annelids is closed.
7. A characteristic feature of reptiles is breathing only with the help of the lungs and a constant body temperature.
8. Amphibians have a three-chambered heart and one circulation.
9. Hedgehog quills are modified hair.
10. Adaptation to a nocturnal lifestyle in animals is expressed primarily in the structure of the eye.
11. Bats have a keel on their sternum.
12. The wall of the right ventricle of the human heart is thicker than that of the left ventricle.
13. In the absence of pathologies, female sex hormones are never formed in the male body.
14. Expiratory reserve volume is the volume of air that can be exhaled after a quiet inhalation.
15. The length of the food chain of living organisms in an ecosystem is limited by the amount of food at each trophic level.
16. When it gets very cold, some birds may hibernate.
17. It has been proven that artificial selection can lead to the formation of new species.
18. Mammals appeared after the extinction of dinosaurs.
19. Arachnoid warts in spiders are homologous to the abdominal limbs.
20. Actin and myosin are not only found in muscle cells.
21. Each codon corresponds to no more than one amino acid.
22. The sucrose molecule consists of two glucose residues.
23. Hydrogen bonds are involved in the formation of the primary structure of a protein.
24. Proteins are unbranched polymers whose monomers are nucleotides.
25. Catabolism is a set of reactions of breakdown and oxidation of various compounds in the body.

Part 4. You are offered test tasks that require matching. The maximum number of points that can be scored is 14.5. Fill out the answer matrices in accordance with the requirements of the tasks.

Task 1. [max. 3 points] The figure shows two types of leaf blades - simple (A) and complex (B). Correlate their numerical designations (1-12) with the type of leaf blade to which they belong.

Task 2. [max. 3 points] Blood (hemolymph) in invertebrate animals has different colors. Select the characteristic color of blood/hemolymph (A–E) for objects (1–6).

Task 3. [max. 3 points] Match the orders of insects (A, B) with the characteristics (1 – 6) characteristic of their representatives.

Task 4. [max. 3 points] Match the formed elements of human blood (A, B) with the signs (1 – 6) characteristic of them.

Task 5. [max. 2.5 points] Match the organic substance (A-D) and the name of the biological material in which it can be found (1-5).

Preview:

Grade 10

Task 1. For each question, choose only one answer, which you consider the most complete and correct. Place a “+” sign next to the index of the selected answer. In case of correction, the “+” sign must be duplicated.

1. The flexibility of the protocuticle of arthropods provides:

a) resilin;

b) chitin;

c) arthropodine;

c) lime.

2. The emergence of the first vertebrates on land in the process of evolution was facilitated by the appearance of:

a) feeding on prepared organic substances and sexual reproduction;

b) five-fingered limbs and warm-bloodedness;

c) devices for breathing atmospheric oxygen and moving on the land surface;

d) pulmonary respiration and sexual process.

3. The mammalian placenta is:

a) the organ in which the embryo develops;

b) the respiratory organ of the embryo;

c) the area of ​​the uterine wall into which the villi of the embryo’s membrane grow;

d) the area of ​​the abdominal wall in which the embryo develops.

4. Fish that can withstand very low oxygen levels in water include:

a) tench;

b) grayling;

c) brown trout;

d) minnow.

5. Badger, polecat, otter belong to the order:

a) predatory;

b) rodents;

c) insectivores;

d) incomplete teeth.

6. General features of the organization of sturgeon and cartilaginous fish:

a) lower transverse mouth, rostrum, equal-lobed caudal fin;

b) rostrum, paired fins arranged horizontally, axial skeleton notochord;

c) arterial cone at the heart, spiral valve in the intestine, unequal-lobed caudal fin, rostrum;

d) long small intestine, aortic bulb, chord, pyloric processes.

7. Hymenoptera insects include;

a) locusts;

b) rider;

c) praying mantis;

d) horseflies.

8. Change in the life cycle of two intermediate hosts: the first – a copepod, the second – a fish:

a) liver fluke;

b) bovine tapeworm;

c) echinococcus;

d) wide tapeworm.

9. The rudiments of subcutaneous muscles first appear in:

a) amphibians;

b) reptiles;

c) birds;

d) mammals.

10. Unlike amphibians, reptiles' eyes:

a) can be retracted;

b) can rotate;

c) push food;

d) have a nictitating membrane.

11. Functions of the root cap:

a) plays the role of a lubricant;

b) excretory function;

c) educational function;

d) suction function.

12. The sexual process called conjugation occurs in:

a) cladophores;

b) chlamydomonas;

b) spirogyra;

d) chlorella.

13. The odd pinnate leaf has:

a) rosehip;

b) birch;

c) rank;

d) rowan.

14. Cocci are:

a) viruses;

b) bacteria;

c) algae;

d) mushrooms.

15. Lactic acid bacteria are:

a) nicrophytes;

b) saprophytes;

d) free-living.

16. Blue-green algae are:

a) heterotrophs;

c) autotrophs;

d) nicrophytes.

17. Mushrooms are:

a) saprophytes;

b) heterotrophs;

c) autotrophs;

18. Cap mushrooms:

a) smut;

b) rusty

c) boletus;

d) moldy.

19. Air cells in:

a) cuckoo flax;

b) corn;

c) sphagnum;

d) goldfish.

20. R 4 L 4 T 9+1 R 1 – this formula refers to:

a) pine;

b) rosehip;

c) radish;

d) potatoes.

21. DNA contains:

a) in the nucleus;

b) mitochondria;

c) lysosomes;

d) nucleus, mitochondria, cytoplasm.

22. Triplets encode:

a) proteins;

b) amino acids;

c) activity;

d) synthesis.

23. Norm of reaction:

a) limits adaptation;

b) expands adaptation;

c) characterizes the variation range of the trait;

d) stabilizes symptoms.

24 Non-cellular life forms are:

a) worms;

b) person;

c) viruses;

d) bacteria.

25. Between adenine and thymine:

a) 2 hydrogen bonds;

b) 1 hydrogen bond;

c) 3 hydrogen bonds;

d) there are no hydrogen bonds.

26. Cristas are formations:

a) nuclear membranes;

b) blind branches of the EPS;

c) lysosome membranes;

d) the inner membrane of mitochondria.

27. Non-homologous chromosomes differ in:

a) color;

b) size;

in the shape of;

d) structure, size, shape.

28. Man exists as a species with:

a) Mesozoic era

b) Paleozoic era

c) Cenozoic era

d) Proterozoic era

29. Mesosoma is:

a) the shell of the ring chromosome

b) nuclear matter

c) multilayer membrane complex

d) part of a ribosome

30. Double-membrane organelles:

a) mitochondria

b) cell center

c) lysosomes

d) EPS

31. Irreversible cell processes:

a) breathing

b) irritability

in motion

d) growth and development

32. Triplet:

a) combination of 3 nucleotides

b) combination of ribosome, enzyme and RNA

c) connection between DNA, protein and enzyme

d) 3 gene sections

33. There is no sympathetic innervation in:

a) heart;

b) lungs;

c) sweat glands;

d) sphincters.

34. Obligatory blood clotting factor:

a) fibrin;

b) hemoglobin;

c) calcium ion;

d) sodium chloride.

35. What process occurs in the large intestine:

a) absorption of the main part of the water;

b) splitting of bile pigments;

c) fermentation of carbohydrates;

d) intensive absorption of nutrients.

a) one joint;

b) two joints;

c) three joints;

d) four joints.

37. An antibody is:

a) enzyme molecule;

b) protein molecule;

c) bone marrow cells;

d) one of the types of leukocytes.

38. The primary centers of the micturition reflex are located in:

a) anterior horns of the spinal cord;

b) medulla oblongata;

c) midbrain;

d) lateral horns of the spinal cord.

39. The function of the convoluted tubule is:

a) reabsorption of substances into the blood;

b) excretion of urine into the external environment;

c) blood filtration;

d) formation of primary urine.

40. Second signaling system:

a) provides concrete thinking

b) present in mammals and humans

c) analyzes specific signals from the external world

d) provides abstract thinking

Task 2. Task with multiple answer options (from 0 to 5). Place a “+” sign next to the indices of the selected answers. In case of corrections, the “+” sign must be duplicated.

1. Circulatory system of mollusks:

a) closed;

b) has capillaries from which blood flows into the space between organs;

c) open;

d) has a heart consisting of chambers;

d) the heart has only an atrium.

2. The fat body of insects performs the function:

a) storage of nutrients;

b) storing water;

c) accumulation of waste products;

d) removal of metabolic products;

e) endocrine gland.

3. Bivalves:

a) slugs,

b) oysters;

c) mussels;

d) scallops;

d) coils.

a) primary body cavity filled with parenchyma;

b) the body is covered with ciliated epithelium;

c) there are sense organs;

d) hermaphroditism;

e) protonephridial excretory system.

5. Bamboo Bear:

a) lives in China;

b) differs from real bears in the structure of teeth and a longer tail;

c) listed in the International Red Book;

d) has long limbs;

d) lives in North America.

6. Plant respiratory organs:

a) mouth;

b) trachea;

c) lentils;

d) sieve tubes;

e) sclereids.

7. The forest is:

a) biogeocenosis;

b) biocenosis;

c) a system of tiers;

d) independent structure;

e) agrocenosis.

8. Sphagnum has:

a) bactericidal properties;

b) the ability to reserve water;

c) photosynthesis;

d) heterotrophy;

e) active movement in space.

9. In the development cycle of cuckoo flax the following take place:

a) outgrowth;

b) teenager;

c) gametophytes;

d) sporophyte;

d) disputes.

10. Chromosome conjugation:

a) occurs in interphase;

b) occurs during cell division;

c) leads to crossing over;

d) ensures the exchange of allelic genes;

e) occurs in a homologous pair.

11. Heterosis:

a) provides hybrid power;

b) possible during hybridization;

c) ensures the stability of a clean line;

d) occurs only in animals;

e) can only be achieved through cloning.

12. Prokaryotes differ from eukaryotes in the absence

a) kernels;

b) ribosomes;

c) EPS;

d) shells;

e) nuclear membrane

13. The peptide chain is characterized by the presence of:

a) peptide bond;

B) amino acids;

c) amino groups;

d) carboxyl group;

e) citrochrome

14. Distance between two neighboring genes:

a) measured in Morganids;

b) calculated in %;

c) determines the probability of crossing over;

d) indicates gene linkage;

e) characterizes the integrity of the chromosome.

15. The work of skeletal muscles is controlled by parts of the nervous system:

a) spinal cord;

b) somatic;

c) cerebral cortex;

d) cerebellum;

e) autonomic nervous system.

16. Speech:

a) is reflexive in nature;

b) 2nd signaling system;

c) 3rd signal system;

d) conditioned reflex function;

e) due to the activity of the cerebral hemispheres.

17. Academician I.P. Pavlov is the founder of the teachings:

a) catch reflexes;

b) analyzers;

c) functional systems;

d) phagocytosis;

e) types of internal income.

Task 3. Task to determine the correctness of judgments (Put a “+” sign next to the numbers of correct judgments).

1. Development with complete metamorphosis is indirect development and is characteristic of mole crickets.
2. The connection between the swim bladder and the balance organ is called Weber's apparatus.
3. Antheridia, as a rule, produce a large number of small male gametes - sperm.
4. Somatic cells differ from each other because they have different genotypes.
5. A neuron and a sperm contain the same number of chromosomes.
6. Down's disease is caused by polyploidy in the chromosome set.
7. Genomic mutations are changes in the number of chromosomes.
8. p 2 – 2pq + q 2 =1 - mathematical model of population genetics according to Chetverikov.
9. In a growing body, dissimilation processes predominate; therefore, it is necessary to consume large amounts of protein
10. In athletes, when performing physical activity, the frequency and depth of breathing simultaneously increases; in fans, this reaction is absent and oxygen starvation of the heart muscle occurs.
11. The cortical centers account for most of the area of ​​the cerebral cortex.
12. Parathyroid hormone introduced into the human body causes a decrease in the concentration of calcium in the blood.

Answer: 2, 5, 6, 10, 11 – (+)

Task 4. Distribute the listed characteristics according to their types:

Coelenterates_____ 01, 03, 04

Flatworms __________ 02, 05, 06, 09 .

Roundworms___________ 02, 05, 07, 0,9.

Arthropods ____________ 02, 05, 08, 09

Chordates _________________ 02, 05, 08, 10

Signs:

1. radially symmetrical;
2. bilaterally symmetrical;
3. lower multicellular organisms;
4. two-layer;
5. three-layer;
6. cavityless;
7. primary cavity;
8. secondary cavity;
9. protostomes;
10. deuterostomes.

Task 5. Solve a biological problem.

The child received different groups of genes from his parents. From the mother - 2% penetrant, 5% complementary, 40% dominant and 15% polymeric. From the father - 1% penetrant, 5% polymer, 20% dominant 10% polymer genes. Penetrant and complementary genes had an allelic arrangement. Which parent is the child more phenotypically similar to? Specify in %.

Answer:

1. with mother (0.5 points)
2. 26% more than with father (0.5 points)

Preview:

ALL-RUSSIAN OLYMPIAD FOR SCHOOLCHILDREN IN BIOLOGY

V.V.Pasechnik, A.M.Rubtsov, G.G.Shvetsov

Moscow 2012

All-Russian Olympiad for schoolchildren in biology in the 2012/2013 academic year

PART II.

EXAMPLES OF ASSIGNMENTS FOR THE ALL-RUSSIAN OLYMPIADS

SCHOOLCHILDREN IN BIOLOGY

Part I. You are offered test tasks that require you to select only one answer.

out of four possible. The maximum number of points that can be scored is

60 (1 point for each test task). The answer index that you think is the most

complete and correct, please indicate in the answer matrix.

1. Under favorable bacterial spore conditions:

a) divides, forming 3–6 new spores;

b) merges with another spore followed by division;

c) dies;

d) germinates into a new bacterial cell.+

2. There are no shelled nuclei in algae cells:

a) green;

b) red;

c) brown;

d) blue-green. +

3. The following cannot be detected in fungal cells:

a) vacuoles;

b) mitochondria;

c) plastids; +

d) ribosomes.

4. Sphagnum reproduces:

a) seeds;

b) pollen;

c) disputes; +

d) zoospores.

5. Most cells of the embryo sac of flowering plants have:

a) haploid set of chromosomes;+

b) diploid set of chromosomes;

c) triploid set of chromosomes;

d) tetraploid set of chromosomes.

6. A person eats the organ(s) of cauliflower:

a) modified apical bud;

b) thickened turnip-like stem;

c) modified inflorescence;+

d) lateral modified buds.

7. The inflorescence of the spike is characteristic of:

a) lily of the valley;

b) lilac;

c) rye;

d) plantain. +

8. Seeds without endosperm for:

a) castor beans;

b) linden;

c) tomato;

d) plantain chastuha.+

9. Root cones are very thick:

a) adventitious roots;+

b) root hairs;

c) main roots;

d) aerial tubers.

10. Infertility is typical for:

a) pears;

b) pineapple; +

c) banana;

d) quince.

11. Root shoot plants include:

a) sea buckthorn;

b) field sow thistle;

c) trembling aspen;

d) all of the listed plants.+

12. Vanilla fragrant is a perennial clinging vine of the family. Orchidaceae. IN

in confectionery production it is used:

a) stems;

b) stems and leaves;

c) inflorescences;

d) fruits. +

13. Semolina is made from:

a) wheat; +

b) millet;

c) oats;

d) barley.

a) development from spores;

b) the presence of a flower;

c) development from seed;+

d) reduction of the sporophyte.

a) rhizomes;

b) flagellates;

c) sunflowers;

d) sporozoans. +

16. The tsetse fly is a carrier of trypanoses that cause in humans:

a) sleeping sickness;+

b) eastern ulcer;

c) malaria;

d) coccidiosis.

17. The study of the obtained specimen of the sponge revealed the presence of durable,

but a fragile silicon skeleton. It is most likely that this sponge is:

a) shallow-water inhabitant;

b) deep-sea inhabitant;+

c) ground dweller;

d) an inhabitant of the tidal zone.

18. Spectrum of color vision in the honey bee:

a) the same as in humans;

b) shifted to the infrared part of the spectrum;

c) shifted to the ultraviolet part of the spectrum;+

d) significantly wider than in humans, on both sides of the spectrum.

19. The development of larvae from eggs laid by roundworms occurs:

a) at a temperature of 37°C, high concentration of CO2, for two weeks;

b) at a temperature of 20-30°C, high concentration of CO2, for two weeks;

c) at a temperature of 37°C, high O2 concentration, for a week;

d) at a temperature of 20-30°C, high O2 concentration, for two weeks.+

20. Unlike roundworms, annelids have:

a) digestive system;

b) excretory system;

c) circulatory system;+

d) nervous system.

21. The wings of insects are on the dorsal side:

a) chest and abdomen;

b) breasts; +

c) cephalothorax and abdomen;

d) cephalothorax.

22. Worker bees are:

a) females who have laid eggs and begun caring for their offspring;

b) females whose gonads are not developed;+

c) young females capable of laying eggs in a year;

d) males developing from unfertilized eggs.

23. Marine iguanas living on the Galapagos Islands excrete excess

salts from the body:

a) with urine;

b) through the salt glands;+

c) through pores in the skin;

d) with excrement.

24. The rhea of ​​the ostrich incubates the eggs and takes care of the chicks:

a) only female;

b) only male; +

c) both parents take turns;

d) adoptive parents into whose nest eggs were thrown.

25. The largest nests among birds are built by:

a) eagles;

b) pelicans;

c) ostriches;

d) African weavers.+

26. Of the listed organisms, the most progressive features

buildings have:

a) amoeba;

b) earthworm;+

c) hydra;

d) Volvox.

27. The complication of the circulatory system corresponds to the evolution of chordates in

a number of the following animals:

a) toad – rabbit – crocodile – shark;

b) shark - frog - crocodile - rabbit;+

c) shark – crocodile – frog – rabbit;

d) crocodile – shark – toad – dog.

28. The greatest species diversity of the inhabitants of the World Ocean is observed:

a) on coral reefs;+

b) in the open ocean in the tropics;

c) in the polar regions;

d) in deep-sea depressions.

29. It is believed that when transferring information from short-term memory to

long-term information loss:

a) 5%;

b) 10%;

c) 50%;

d) more than 90%. +

30. Cellulose that has entered the human gastrointestinal tract:

a) does not break down due to the lack of a specific enzyme;

b) partially broken down by bacteria in the large intestine;+

c) is broken down by salivary amylase;

d) is broken down by pancreatic amylase.

31. What is the reaction of the environment in the duodenum:

a) slightly acidic;

b) neutral;

c) slightly alkaline;+

d) alkaline.

32. There are no known hormones that are derivatives of:

a) proteins;

b) amino acids;

c) lipids;

d) carbohydrates. +

33. During the digestion process, proteins are broken down into:

a) glycerol;

b) fatty acids;

c) monosaccharides;

d) amino acids. +

34. Symptoms such as damage to the oral mucosa, peeling

skin, cracked lips, tearing, photophobia, indicate a deficiency:

a) tocopherol;

b) pyridoxine;

c) riboflavin; +

d) folic acid.

35. Skin receptor that responds to cold:

a) Pchini body;

b) Meissner's body;

c) nerve plexus around the hair follicle;

d) Krause flask. +

36. Viral diseases do not include:

a) measles;

b) tick-borne encephalitis;

c) rubella;

d) diphtheria. +

37. The food chain is:

a) a sequence of organisms in a natural community, each element of which is

food for the next;+

b) sequential passage of food through various sections of the digestive tract;

c) the dependence of plants on herbivores, and them, in turn, on predators;

d) the totality of all food connections in the ecosystem.

38. Constant human intervention is required for existence:

a) freshwater ecosystems;

b) natural terrestrial ecosystems;

c) ecosystems of the World Ocean;

d) agrocenoses. +

39. In natural conditions, natural carriers of the plague pathogen

are:

a) birds;

b) rodents; +

c) ungulates;

d) person.

40. In the vast forests of the North, so-called

concentrated logging using heavy equipment, which results in:

a) to the replacement of forest ecosystems by swamps;+

b) to desertification or complete destruction of ecosystems;

c) to increase the share of tree species that are more valuable from an economic point of view;

d) to the process of converting organic residues into humus in the soil.

41. The leaves of succulents - plants of arid habitats - are characterized by:

a) reduced stomata; undifferentiated mesophyll; lack of cuticle;

developed aerenchyma;

b) frequent dissection, absence of mechanical tissue;

c) thick cuticle; powerful wax coating; cells with large vacuoles; submerged

stomata; +

d) well-developed sclerenchyma; predominance of bound water.

42. Of the named organisms, the superkingdom of prokaryotes includes:

a) green euglena;

b) ciliate-slipper;

c) amoeba;

d) staphylococcus. +

43. Two breeds of dogs, for example, the lapdog and the German shepherd, are animals:

a) the same type, but with different external characteristics;+

b) two species, one genus and one family;

c) two species, two genera, but one family;

d) one species, but living in different environmental conditions.

44. The science that studies the development of living nature from prints and fossils,

which are found in the earth's crust:

a) systematics;

b) history;

c) paleontology;+

d) evolution.

45. The first land vertebrates descended from fish:

a) ray-finned;

b) lobe-finned; +

c) whole-headed;

d) lungfish.

46. ​​The body contours of the flying squirrel, marsupial flying squirrel, and woolly wing are very similar.

This is a consequence:

a) divergence;

b) convergence; +

c) parallelism;

d) random coincidence.

47. The number of chromosomes during sexual reproduction increased in each generation

would have doubled if the process had not been formed during evolution:

a) mitosis;

b) meiosis; +

c) fertilization;

d) pollination.

48. One of the provisions of the cell theory says:

a) during cell division, chromosomes are capable of self-duplication;

b) new cells are formed when the original cells divide;+

c) the cytoplasm of cells contains various organelles;

d) cells are capable of growth and metabolism.

49. During parthenogenesis, the organism develops from:

a) zygotes;

b) vegetative cell;

c) somatic cell;

d) an unfertilized egg.+

50. The matrix for translation is a molecule:

a) tRNA;

b) DNA;

c) rRNA;

d) mRNA. +

51. Circular DNA is characteristic of:

a) mushroom kernels;

b) bacterial cells;+

c) animal kernels;

d) plant kernels.

52. Separate cells, organelles or organic macromolecules according to their

density can be used using the method:

a) chromatography;

b) centrifugation;+

c) electrophoresis;

53. Monomers of nucleic acids are:

a) nitrogenous bases;

b) nucleosides;

c) nucleotides; +

d) dinucleotides.

54. Magnesium ions are part of:

a) vacuoles;

b) amino acids;

c) chlorophyll; +

d) cytoplasm.

55. In the process of photosynthesis, a source of oxygen (by-product)

is:

a) ATP

b) glucose;

c) water; +

d) carbon dioxide.

56. Of the plant cell components, the tobacco mosaic virus infects:

a) mitochondria;

b) chloroplasts; +

c) core;

d) vacuoles.

57. Of the named proteins, the enzyme is:

a) insulin;

b) keratin;

c) thrombin; +

d) myoglobin.

58. In the chloroplasts of plant cells, light-harvesting complexes

located

a) on the outer membrane;

b) on the inner membrane;

c) on the thylakoid membrane;+

d) in the stroma.

59. Non-allelic interaction of genes during dihybrid crossing can

give splitting in the second generation:

a) 1:1;

b) 3:1;

c) 5:1;

d) 9:7. +

60. In marriages between people of Caucasian and Negroid races in the second

generation there are usually no people with white skin color. It's connected with:

a) incomplete dominance of the skin pigmentation gene;

b) polymerization of skin pigmentation genes;+

c) epigenomic inheritance;

d) non-chromosomal heredity.

Part II. You are offered test tasks with one answer option out of four

possible, but requiring preliminary multiple choice. Maximum amount

points that can be scored - 30 (2 points for each test task).

The index of the answer that you consider to be the most complete and correct, indicate in the matrix

answers.

1. Bacteria cause diseases:

I. relapsing fever.+

II. typhus. +

III. malaria.

IV. tularemia. +

V. hepatitis.

a) II, IV;

b) I, IV, V;

c) I, II, IV; +

d) II, III, IV, V.

2. Roots can perform the following functions:

I. kidney formation.+

II. leaf formation.

III. vegetative propagation.+

IV. absorption of water and minerals.+

V. synthesis of hormones, amino acids and alkaloids.+

a) II, III, IV;

b) I, II, IV, V;

c) I, III, IV, V;+

d) I, II, III, IV.

3. If you break off (cut off) the tip of the main root:

I. the root will die.

II. the entire plant will die.

III. root growth in length will stop.+

IV. the plant will survive, but will be weak.

V. lateral and adventitious roots will begin to grow.+

a) III, IV, V;

b) III, V;+

c) I, IV, V;

d) II, IV, V.

4. Among arachnids, development with metamorphosis is typical for:

I. spiders.

II. ticks.+

III. salpug.

IV. haymakers.

V. scorpions.

a) II;+

b) II, III;

c) I, IV;

d) I, II, III, V.

5. Animals leading an attached (sedentary) lifestyle, but

having free-swimming larvae are:

I. corals.+

II. sponges.+

III. ascidians.+

IV. rotifers.

V. barnacles.+

a) I, II, III, IV;

b) I, II, III, V;+

c) I, III, IV;

d) I, II, III, IV, V.

6. The notochord remains throughout life in:

I. perch.

II. sturgeon.+

III. sharks.

IV. lampreys.+

V. lancelet.+

a) I, II, III, IV;

b) III, IV, V;

c) II, III, V;

d) II, IV, V.+

7. Spawns only once in a lifetime:

I. stellate sturgeon.

II. sardine.

III. pink salmon.+

IV. rudd

V. river eel.+

a) II, III, V;

b) III, V;+

c) I, III, V;

d) I, II, III, V.

8. Allantois performs the following function in amniotes:

I. gas exchange.+

II. thermoregulation.

III. storing water.

IV. urine accumulation.+

V. digestion.

a) I, III, IV;

b) I, IV;+

c) I, II, IV, V;

d) I, II, III, IV.

9. Normally, the following are practically not filtered in the renal glomerulus:

I. water.

II. glucose.

III. urea.

IV. hemoglobin.+

V. plasma albumin.+

a) I, II, III;

b) I, III, IV, V;

c) II, IV, V;

d) IV, V. +

10. Each population is characterized by:

I. density.+

II. in number.+

III. degree of insulation.

IV. independent evolutionary fate.

V. the nature of spatial distribution.+

a) I, II, V;+

b) I, IV, V;

c) II, V;

d) II, III, IV.

11. Predators that typically hunt from ambush include:

I. wolf.

II. lynx.+

III. jaguar.+

IV. cheetah.

V. bear.+

a) II, III, IV, V;

b) I, IV;

c) I, II, III, V;

d) II, III, V.+

12. Of the listed animals, the tundra biocenosis includes:

I. squirrel.

II. ferret.

III. arctic fox+

IV. lemming.+

V. green toad.

a) I, II, III, IV;

b) II, III, IV, V;

c) III, IV;+

d) III, IV, V.

13. Similar organs that developed during evolution:

I. fish gills and crayfish gills.+

II. butterfly wings and bird wings.+

III. pea tendrils and grape tendrils.+

IV. mammal hair and bird feathers.

V. cactus spines and hawthorn spines.+

a) I, III, IV, V;

b) I, II, IV, V;

c) I, II, III, V;+

d) I, II, III, IV.

14. Of the named polymers, unbranched ones include:

I. chitin.+

II. amylose+

III. glycogen.

IV. cellulose.+

V. amylopectin.

a) I, II, IV;+

b) I, II, III, IV;

c) II, IV, V;

d) III, IV, V.

15. In the human body, hormonal functions are performed by compounds:

I. proteins and peptides.+

II. nucleotide derivatives.

III. cholesterol derivatives.+

IV. amino acid derivatives.+

V. derivatives of fatty acids.+

a) III, IV, V;

b) I, III, IV, V;+

c) III, V;

d) II.

Part III. You are offered test tasks in the form of judgments, with each of which

must either agree or reject. In the answer matrix, indicate the answer option

"Yes or no". The maximum number of points you can score is 25.

1. Liver mosses are lower plants.

2. Gametes in mosses are formed as a result of meiosis.

3. Starch grains are leucoplasts with starch accumulated in them.+

4. After fertilization, the ovules turn into seeds, and the ovary into a fruit.

5. In all invertebrate animals, fertilization is external.

6. Hemolymph of insects performs the same functions as the blood of vertebrates

animals.

7. All representatives of the order of reptiles have a three-chambered heart.

8. Domestic animals tend to have larger brains than their wild counterparts.

ancestors

9. The first crocodiles were land reptiles.+

10. A characteristic feature of all mammals is viviparity.

11. Unlike most mammals, humans are characterized by the presence

seven cervical vertebrae and two occipital condyles.

12. In the human gastrointestinal tract, all proteins are completely digested.

13. Hypervitaminosis is known only for fat-soluble vitamins.+

14. The human brain consumes approximately twice as much energy per gram of weight,

than a rat.

15. During heavy physical work, body temperature can rise to 39

degrees.+

16. Viral infections are usually treated with antibiotics.

17. Nutrient cycles can be studied by introducing radioactive

markers into natural or artificial ecosystems.+

18. Succulents easily tolerate dehydration.

19. Succession after deforestation is an example of secondary succession.+

20. Genetic drift can play the role of an evolutionary factor only in very few

populations.+

21. Genetic information in all living organisms is stored in the form of DNA.

22. Each amino acid corresponds to one codon.

23. In prokaryotes, the processes of translation and transcription occur simultaneously

and in the same place.+

24. The largest molecules in living cells are DNA molecules.+

25. All hereditary diseases are associated with mutations in chromosomes.

Part IV. You are offered test tasks that require matching.

The maximum number of points you can score is 13. Fill out the matrices

answers in accordance with the requirements of the tasks.

1. [max. 3 points] Blood (hemolymph) in invertebrate animals has

different colors. Select a characteristic blood color for objects (1–6)

hemolymph (A–E).

1) earthworm; A – red;

2) serpul polychaete worm; B – blue;

3) cuttlefish; B – green;

4) crayfish; G – orange-yellow;

5) larva of the mosquito mosquito (genus Chironomus); D – black;

6) Moroccan locust. E – colorless.

2. It is known that high salt content in the soil creates

it has a sharply negative water potential, which leads to disruption of the flow

water into plant root cells, and sometimes to damage to cell membranes. Select

adaptations found in plants growing in saline areas

soils.

01. Root cells of salt-tolerant plants are able to absorb salts and release them through

secreting cells on leaves and stems;

02. The cell contents of salt-tolerant plants have a more negative water content

potential compared to cells of other plants;

03. Cells are characterized by a high salt content;

04. The cytoplasm of the cells of these plants has low hydrophilicity;

05. The cytoplasm of cells of salt-tolerant plants is highly hydrophilic;

06. Cells of salt-tolerant plants are characterized by a less negative water potential,

than in the surrounding soil solution;

07. The intensity of photosynthesis in plants growing on saline soils is low;

08. The intensity of photosynthesis in these plants is high.

3. The figure shows a transverse

cut of a vascular tuft of potato (Solanum tuberosum).

Match the main structures of the conductive bundle (A–D)

with their designations in the figure.

A – main parenchyma;

B – external phloem;

B – cambium;

G – xylem;

D – internal phloem.

4. Establish in what sequence (1 – 5) the

DNA reduplication process.

A) unwinding of the helix of the molecule

B) the effect of enzymes on the molecule

C) separation of one chain from another into parts of a DNA molecule

D) attachment of complementary nucleotides to each DNA strand

D) the formation of two DNA molecules from one

5. Match the organic compound

(A – D) and the function it performs (1 – 5).

1. Fungal cell wall component A. Starch

2. Plant cell wall component B. Glycogen

3. Bacterial cell wall component B. Cellulose

4. Plant storage polysaccharide G. Murein

5. Mushroom storage polysaccharide D. Chitin

Internet resources

1. Assignments from the All-Russian Biology Olympiad for schoolchildren from previous years, as well as

2. Official website of the International Biological Olympiadwww.ibo-info.org

3. Regional website of the All-Russian Olympiad for schoolchildren (Moscow region)

in biology, chemistry, geography and ecology –www.olimpmgou.narod.ru

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12. General biology. 10-11 grades / D.K.Belyaev, N.N.Vorontsov, G.M.Dymshits and others.

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14. Pasechnik V.V. "Biology. Bacteria. Fungi. Plants. 6th grade", - M.: Bustard,

1997 and other reissues;

15. Ponomareva I. N. et al. “Biology, 6th grade. Plants. Bacteria. Fungi. Lichens,

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16. Ponomareva I. N., Kornilova O. A., Chernova N. M. “Fundamentals of general biology.

9th grade", - M.: Ventana-Graf, 2000 and other reprints.

17. Sonin N. I. "Biology. Living organism. Grade 6", - M.: Bustard, 1997 and others

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18. Sonin N. I., Sapin M. R. "Biology. Man. 8th grade", - M.: Bustard, 2000 and

other reissues;

19. Khripkova A. G., Kolesov D. V. "Biology. Man and his health. Grade 9",

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20. Pasechnik V.V., Kalinova G.S., Sumatokhin S.V. Biology 6th grade. Textbook

for educational institutions. –M.: Education, 2008.

21. Pasechnik V.V., Kalinova G.S., Sumatokhin S.V. Biology 7th grade. Textbook

for educational institutions. –M.: Education, 2009.

22. Pasechnik V.V., Kamensky A.A., Shvetsov G.G. Biology 8th grade. Tutorial for

educational institutions. –M.: Education, 2010.

Internet source