Interesting such observation. In animal northern populations, all elongated parts of the body - limb, tail, ears are covered with a dense layer of wool and look relatively shorter than representatives of the same species, but inhabitant in a hot climate.

This pattern, known as alena, is distributed both on wild and on pets.

The difference in the structure of the body of north foxes and phenka in the south, northern boar and boar in the Caucasus are noticeable. Mongrel homemade dogs in the Krasnodar Territory, the cattle of local selection are characterized by a smaller live weight compared to representatives of these species, say, Arkhangelsk.

Often animals from southern populations of long-legs and longs. Large ears, unacceptable in low temperatures, arose as a device for life in a hot belt.

And animal tropics have just huge ears (elephants, rabbits, hoofs). The ears of the African Elephant are indicative, the area of \u200b\u200bwhich is 1/6 of the surface of the entire body of the animal. They have abundant innervation and vascularization. In hot weather, an elephant through the circulatory system, the sinks of the ears runs about 1/3 of the entire circulating blood. As a result of reinforced blood flow to the external environment, it is excessive heat.

More impressive with its adaptation abilities to high temperatures, a resident of the desert hare Lapus Alleni. This rodent has 25% of the entire body surface falls on naked ear shells. It is unclear what is the main biological task of such ears: in time to fix the approach of danger or participate in thermoregulation. Both the first and the second task are solved by the animal very effectively. The rodent has a thin rumor. The developed circulatory system of the oars with a unique vascular ability serves only thermoregulation. Due to the strengthening and limiting blood flow through ear sinks, the animal changes the heat transfer by 200-300%. His hearing organs perform the function of maintaining thermal homeostasis and water saving.

Due to the saturation of the abnormal sinks by heat-sensitive nerve endings and rapid vascular reactions from the surface of the auricles into the external environment, a large number of extra thermal energy is given to the external environment, and especially at Lepusa.

Well fits into the context of the problem discussed and the structure of the body of a relative of contemporary elephants - Mammoth. This northern analogue of the elephant, judging by the preserved remains found in the tundra, was significantly larger than his southern relative. But the ears of the mammoth had a smaller relative area and besides were covered with thick wool. Mammoth had relatively short limbs and a short trunk.

Long limbs are unprofitable under conditions of low temperatures, since too many thermal energy is lost from their surface. But in the conditions of hot climate, long limbs are useful adaptation. In the desert conditions of camels, goats, horses of local selection, as well as sheep, cats, as a rule, long-legs.

According to N. Hensen, as a result of adaptation to low temperatures, animals change the properties of fat sediments and bone marrow. The Arctic animals have bone fat from the phalange of the fingers have a low melting point and does not freeze even into the tall frosts. However, bone fat from bones that cannot be contacted with a cold surface, for example, from the femur, has conventional physicochemical properties. Liquid fat in the bones of the lower part of the limbs ensures thermal insulation and mobility of the joints.

The accumulation of fat is not only not only in northern animals for which it serves as thermal insulation and source of energy during the period when the feed is unavailable due to heavy bad weather. Fat accumulates and animals living in a hot climate. But the quality, quantity and distribution of fat by body in the northern and southern animals is different. In wild arctic animals, fat is distributed in the subcutaneous tissue evenly throughout the body. In this animal, a peculiar heat insulating capsule is formed.

In animals moderate belt fat as the heat insulator accumulates only at species with a weakly developed coat. In most cases, the accumulated fat serves as a source of energy into a hungry winter (or summer) period.

In the hot climate, subcutaneous greases carry another physiological burden. The distribution of fatty sediments on the body of animals is characterized by a large unevenness. Fat is localized in the upper and rear parts of the body. For example, at the uncoid African savannah, the fat subcutaneous layer is localized along the spine. She protects the animal from the scorching sun. Belo at the same time absolutely free from fat. It also has a lot of meaning. A colder land, grass or water compared to air provides an effective heat removal through the abdominal wall in the absence of a fat layer. Small fatty deposits and animals in the hot climate are the source of energy for the period of drought and the hungry existence of herbivores associated with it.

The inner fat of animals in a hot and arid climate performs another extremely useful feature. In the context of a lack or complete lack of water, the inner fat serves as a source of water. Special studies show that the oxidation of 1000 g of fat is accompanied by the formation of 1100 g of water.

A sample of unpretentiousness in dry conditions of the desert is served by camels, roasted and fatty sheep, zebuvid cattle. The mass of the camel accumulated in the humps and the kurdyuk the fat sheep is 20% of their live masses. Calculations show that 50-kilogram roasted sheep with itself has a supply of about 10 liters, and the camel is even more - about 100 liters. Recent examples illustrate morphophysiological and biochemical adaptation of animals to extreme temperatures. Morphological adaptations apply to many organs. Northern animals have a large volume of the gastrointestinal tract and a large relative intestinal length, they have more inland fat in the glands and an octopic capsule.

Animal arid zone has a series of morphofunctional features of the system of urica and selection. Even at the beginning of the XX century. Morphologists have discovered differences in the structure of kidney of desert animals and animal temperate climates. In animals of hot climate, it is more developed by a brain layer due to an increase in the straight-span part of the nephron.

For example, in African Lion, the thickness of the cereal brain layer is 34 mm, and the home pig is only 6.5 mm. The ability of the kidneys to concentrate urine correlates with the length of the loop of the gendle.

In addition to the structural features, the animals of the arid zone found the functional features of the urinary system. So, for a kangaron rat, the pronounced bladder ability to reabsorb water from the composition of secondary urine is normal. In the ascending and downward channels of the loop Gentle, urea filtration occurs - the process, usual for the nodule of the nephron.

The adaptation functioning of the urinary system is neuro-humoral regulation with a pronounced hormonal component. In Kangarur Rat, the concentration of vasopressin hormone is increased. Thus, in the urine of Kangaron rat, the concentration of this hormone is 50 units / ml, in a laboratory rat - only 5-7 units / ml. In the tissue of the kangarur rat, the vasopressin content is 0.9 units / mg, in the laboratory rat - three times less (0.3 units / mg). When water deprivation, the differences between animals are preserved, although the secretory activity of neurohypophyse is enhanced by one and another animal.

Loss of live masses when deprivation of water in arid animals below. If a camel for a working day, obtaining only low quality hay, loses 2-3% of the living mass, then the horse and donkey in the same conditions will lose 6-8% of the live weight due to dehydration.

The temperature of the habitat has a significant effect on the structure of animal skin. In the cold climate, the skin is thicker, the wool is thick, there is puffs. All this helps to reduce the thermal conductivity of the body surface. In animals of hot climate, the opposite: thin skin, rare wool, low thermal insulating properties of the skin as a whole.

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Reactions to adverse environmental factors only under certain conditions are detachious for living organisms, and in most cases they have an adaptive value. Therefore, these responses were named Selle "General Adaptation Syndrome". In later works, the terms "Stress" and "Common Adaptation Syndrome" he used as synonyms.

Adaptation - This is a genetically deterministic process for the formation of protective systems that ensure an increase in the stability and the flow of ontogenesis into unfavorable conditions for it.

Adaptation is one of the most important mechanisms that increases the stability of the biological system, including vegetable organism, in the changed conditions of existence. The better the body is adapted to some factor, the more stable to its oscillations.

The genotypically determined ability of the body to change metabolism within certain limits, depending on the action of the external environment is called round reaction. It is controlled by genotype and is peculiar to all living organisms. Most modifications that occur within the reaction rate are adaptive. They correspond to changes in habitat and provide better plant survival with fluctuations in environmental condition. In this regard, such modifications have evolutionary importance. The term "reaction rate" was introduced by V.L. Johansen (1909).

The greater the ability of the type or variety to be modified in accordance with the environment, the wider its reaction rate and the above ability to adapt. This property is distinguished by stable agricultural crops. As a rule, non-core and short-term changes in the factors of the external environment do not lead to essential violations of physiological functions of plants. This is due to their ability to maintain a relative dynamic equilibrium of the inner medium and the stability of the main physiological functions in the conditions of a changing external environment. At the same time, sharp and long exposure leads to a violation of many plants functions, and often to his death.

Adaptation includes all processes and devices (anatomical, morphological, physiological, behavioral, etc.), which contribute to increasing stability and contribute to the survival of the species.

1. Anatomo morphological devices. In some representatives of xerophytes, the length of the root system reaches several tens of meters, which allows the plant to use groundwater and not to test the lack of moisture under conditions of soil and atmospheric drought. In other xerophytes, the presence of thick cuticle, the pubescence of the leaves, the conversion of leaves in the spins reduce the loss of water, which is very important in conditions of lack of moisture.

Burning hairs and spines protect plants from eating animals.

Trees in the tundra or at large mountain altitudes have the kind of squat steering shrubs, in the winter they fall asleep with snow, which protects them from severe frosts.

In mountainous areas with large daily fluctuations in the temperature of the plant often have the form of splashing pillows with tightly located numerous stems. This allows you to maintain inside the pillows moisture and relatively uniform temperatures during the day.

The marsh and aqueous plants are formed a special air-capable parenchyma (Aerrenhima), which is the air tank and makes it easier to breathing the parts of the plant, immersed in water.

2. Physiology-biochemical devices. Succulent adaptation for growing in the conditions of deserts and semi-desert is the assimilation of CO 2 during the photosynthesis by the CAM path. These plants are closed in these plants. Thus, the plant retains the internal reserves of water from evaporation. In the deserts, water is the main factor limiting the growth of plants. Stitza open at night, and at this time there is an admission of CO 2 into photosynthetic fabrics. The subsequent involvement of CO 2 to the photosynthetic cycle occurs during the day with closed dusts.

Physiological and biochemical devices include the ability of alloys to open and close, depending on external conditions. Synthesis in abscissoic acid cells, proline, protective proteins, phytooaexins, phytoncides, increasing the activity of enzymes, opposing the oxidative decay of organic substances, accumulation of sugars in cells and a number of other changes in the metabolism contributes to increasing plant resistance to adverse environmental conditions.

The same biochemical reaction can be carried out by several molecular forms of the same enzyme (isoenzymes), while each isoform exhibits catalytic activity in a relatively narrow range of some environmental parameter, such as temperature. The presence of a number of isoenzymes allows the plant to react to a significantly wider range of temperatures, compared with each individual isoenzyme. This makes it possible to plant successfully perform life functions in changing temperature conditions.

3. Behavioral devices, or avoiding the action of an adverse factor. An example is epfemeers and ephemeroids (poppy, star, crocuses, tulips, snowdrops). They pass the whole cycle of their development in the spring for 1.5-2 months, even before the onset of heat and drought. Thus, they seek, or avoid entering the influence of the stressor. Similarly, the early-weighted varieties of crops form a harvest before the occurrence of adverse seasonal phenomena: August fogs, rains, frosts. Therefore, the selection of many crops is aimed at creating early varieties. Perennial plants winter in the form of rhizomes and bulbs in the soil under snow protecting them from freezing.

Adaptation of plants to adverse factors is carried out simultaneously at many levels of regulation - from a separate cell to phytocenosis. The higher the level of the organization (cell organism, population). The greater the number of mechanisms simultaneously participates in the adaptation of plants to stress.

Regulation of metabolic and adaptation processes inside the cell is carried out using systems: metabolic (enzymatic); genetic; Membrane. These systems are closely related to each other. Thus, the properties of membranes depend on gene activity, and the differential activity of the genes themselves is under the control of membranes. Enzyme synthesis and their activity are controlled at the genetic level, at the same time enzymes regulate nucleic exchange in the cell.

On the organize level New, reflecting the interaction of organs is added to the cellular mechanisms of adaptation. In adverse conditions, plants create and preserve such a number of fruit elements, which in sufficient quantities are provided with the necessary substances to form full-fledged seeds. For example, in the inflorescences of cultural cereals and in crowns of fruit trees in unfavorable conditions, more than half of the laid barriers may fall. Such changes are based on competitive relations between organs for physiologically active and nutrients.

In conditions of stress, the processes of aging and the fear of the lower leaves are sharply accelerated. At the same time, the substances desired by plants move from them into young organs, responding to the body survival strategy. Thanks to the reutilization of nutrients from the lower leaves, viable younger - the upper leaves are preserved.

There are mechanisms for regeneration of lost bodies. For example, the surface of the injury is covered by a secondary coating cloth (wounded periderma), the wound on the trunk or branch is frozen (calls). With the loss of the top shooting, the plants are awakening sleeping kidneys and lateral shoots are developing. Spring restoration of leaves instead of fallen autumn is also an example of natural regeneration of organs. Regeneration as a biological device, providing vegetative reproduction of plants with sections of the root, rhizomes, layers, stroke and sheet cuttings, isolated cells, individual protoplasts, is of great practical importance for crop production, fruit growing, forestry, decorative gardening, etc.

In the processes of protection and adaptation at the plant level, the hormonal system is also involved. For example, under the action of unfavorable conditions in the plant, the content of growth inhibitors: ethylene and abscissa acid increases. They reduce metabolism, inhibit growth processes, accelerate aging, exhausting organs, transition of plants into rest state. The inhibition of functional activity in stress conditions under the influence of growth inhibitors is a reaction characteristic of plants. At the same time, the content of growth stimulants is reduced in the tissues: cytokinin, auxin and gibbersellin.

On the population level The selection is joined, which leads to the appearance of more adapted organisms. The possibility of selection is determined by the existence of intrapopulation variability of plant resistance to various factors of the external environment. An example of inspirational variability in stability can be the non-departure of the emergence of seractions on saline soil and an increase in varying germination time when the stressor is increased.

The view in the modern presentation consists of a large number of biotypes - smaller environmental units, genetically identical, but manifesting different resistance to the factors of the external environment. In various conditions, not all biotypes are equally vitality, and as a result of competition, only those of them remain, which most meaning these conditions. That is, the stability of the population (varieties) to one or another factor is determined by the stability of the components of the population of organisms. Sustainable varieties are in their composition a set of biotypes that provide good productivity even in adverse conditions.

At the same time, in the process of many years of cultivation in varieties, the composition and the ratio of biotypes in the population is changed, which is reflected on productivity and quality of the variety, often not for the better.

So, adaptation includes all processes and devices that increase the stability of plants to adverse environmental conditions (anatomical, morphological, physiological, biochemical, behavioral, population, etc.)

But to select the most effective way to adapt the main time during which the body should adapt to new conditions.

In case of a sudden action of an extreme factor, the answer cannot be postponed, it must follow immediately to eliminate irreversible damage to the plant. With prolonged exposure to a small force, adaptive restructuring occurs gradually, while the choice of possible strategies increases.

In this regard, three main adaptation strategies are distinguished: evolutionary, ontogenetic and urgered. The task of the strategy is to efficiently use available resources to achieve the main goal - the survival of the body in stress. The adaptation strategy is aimed at maintaining the structural integrity of vital macromolecules and the functional activity of cellular structures, the preservation of system regulation systems, providing plants with energy.

Evolutionary, or phylogenetic adaptation (Phylogenesis - the development of biological species in time) is adaptations arising during the evolutionary process based on genetic mutations, selection and inherited. They are most reliable to survive plants.

Each type of plants in the process of evolution developed certain needs for the conditions of existence and the adaptation to the ecological niche occupied by it, the resistant adaptation of the body to the habitat. Moistlability and shadowness, heat resistance, cold resistance and other environmental features of specific plant species were formed as a result of a long action of the relevant conditions. Thus, the thermal loving and short-lasting plants are characteristic of southern latitudes, less demanding to heat and the long-term plants - for the northern. Numerous evolutionary adaptations for drought-xerophyte plants are well known: economical water spending, a deeply occurring root system, dropping the leaves and the transition to the rest state and other devices.

In this regard, agricultural plant varieties are sustainable precisely to the factors of the external environment, against the background of which the selection and selection of productive forms is carried out. If the selection passes in a number of consecutive generations against the background of the constant influence of any adverse factor, then the stability of the grade to it can be significantly increased. It is natural that the breeding varieties of the southeast agriculture (Saratov), \u200b\u200bmore resistant to drought than grades created in the selection centers of the Moscow region. In the same way, in ecological zones with unfavorable short-lumility conditions, sustainable local varieties of plants were formed, and endemic plants are stable precisely to the stressor, which is expressed in the arale of their habitat.

Characteristics of the stability of varieties of spring wheat from the collection of the All-Russian Planting Institute (Semenov et al., 2005)

Variety Origin Sustainability
Enita Moscow region Medium drought-resistant
Saratov 29. Saratov region Drought-resistant
Comet Sverdlovsk region. Drought-resistant
Karazino Brazil Acid-resistant
Prelude Brazil Acid-resistant
Colonias. Brazil Acid-resistant
Trintany Brazil Acid-resistant
PPG-56. Kazakhstan Soleustable
Osh Kyrgyzstan Soleustable
Surhak 5688. Tajikistan Soleustable
Meskel Norway Solenostable

In the natural environment, the environment conditions usually change very quickly, and the time during which the stressful factor reaches the damaging level, is not enough to form evolutionary devices. In these cases, plants are not constant, and the protective mechanisms induced by stressor, the formation of which is genetically predetermined (deterministic).

Ontogenetic (phenotypic) adaptation Not related to genetic mutations and are not inherited. The formation of this kind of adaptation requires a relatively long time, so they are called long-term adaptation. One such mechanisms is the ability of a row of plants to form the water-saving path of the Cam-type photosynthesis in a water deficit caused by drought, salinization, the action of low temperatures and other stressors.

This adaptation is associated with the induction of the expression of "inactive" under normal conditions of phosphoenolpiruvataukarboxylase genes and genes of other CAM-path enzymes of CO 2, with the osmolite biosynthesis (proline), with activation of antioxidant systems and the change in the daily rhythms of alloying movements. All this leads to very economical water spending.

In field crops, for example, in corn, Aerrenakhim is absent under normal conditions. But in the conditions of flooding and disadvantage in oxygen tissues in the roots, it occurs the death of a part of the cells of the primary root and stem cell (apoptosis, or programmable cell death). In their place, cavities are formed by which oxygen from the above-ground part of the plant is transported to the root system. The signal for cell death is ethylene synthesis.

Urgent adaptation It occurs at fast and intensive changes in habitat. It is based on the formation and functioning of shock protective systems. The shock protective systems include, for example, a heat shock protein system, which is formed in response to a rapid increase in temperature. These mechanisms provide short-term survival conditions under the action of a damaging factor and thereby create prerequisites for the formation of more reliable long-term specialized adaptation mechanisms. An example of specialized adaptation mechanisms is the neoplasm of antifreeze proteins at low temperatures or synthesis of sugars in the process of overwrieving winter crops. At the same time, if the damaging effect of the factor exceeds the protective and reparation capabilities of the body, then death comes inevitably. In this case, the body dies at the stage of urgent or at the stage of specialized adaptation depending on the intensity and duration of the extreme factor.

Distinguish specific and nonspecific (general) Response reactions of plants on stressor.

Non-specific reactions Do not depend on the nature of the acting factor. They are the same under the action of high and low temperatures, lack or excess moisture, high saline concentration in soil or harmful gases in the air. In all cases, membranes permeability increases in plant cells, breathing is disturbed, the hydrolytic decay of substances increases, the synthesis of ethylene and abscisic acid increases, the division and stretching of the cells is inhibited.

The table presents a complex of non-specific changes that occur in plants under the influence of various factors of the external environment.

Changes in physiological parameters in plants under the action of stressful conditions (according to GV, Udovenko, 1995)

Parameters The nature of changes in parameters in conditions
drought salinization high temperatures low temperature
Concentration of ions in tissues Grows Grows Grows Grows
Water activity in a cell Fall Fall Fall Fall
Osmotic potential of cells Grows Grows Grows Grows
Water-holding ability Grows Grows Grows —
Water deficit Grows Grows Grows —
Permeability of protoplasm Grows Grows Grows —
Transpiration intensity Fall Fall Grows Fall
Transpiration efficiency Fall Fall Fall Fall
Energy efficiency of breathing Fall Fall Fall —
Intensity of breathing Grows Grows Grows —
Photo phosphorylation Reduced Reduced — Reduced
Stabilization of nuclear DNA Grows Grows Grows Grows
Functional activity DNA Reduced Reduced Reduced Reduced
Concentration of Proline Grows Grows Grows —
The content of water-soluble proteins Grows Grows Grows Grows
Synthetic reactions Depressed Depressed Depressed Depressed
The absorption of ions roots Depressed Depressed Depressed Depressed
Transportation substances Depressed Depressed Depressed Depressed
Pigments concentration Fall Fall Fall Fall
Cell division Brake Brake — —
Stretching cells Depressed Depressed — —
Number of fruit elements Reduced Reduced Reduced Reduced
Aging organs Accelerated Accelerated Accelerated —
Biological harvest Low Low Low Low

Based on the data of the table, it can be seen that the stability of plants to several factors is accompanied by unidirectional physiological changes. This gives reason to believe that increasing the stability of plants to one factor may be accompanied by an increase in resistance to another. This is confirmed by experiments.

Experience at the Institute of Plant Physiology RAS (VL. V. Kuznetsov et al.) It is shown that short-term thermal treatment of cotton plants is accompanied by an increase in their resistance to subsequent salinization. And the adaptation of plants to salinity leads to an increase in their resistance to high temperature. The heat shock increases the ability of plants to adapt to the subsequent drought and, on the contrary, in the process of drought, the body's resistance to high temperature increases. A short-term exposure to high temperatures increases heavy metals and UV radiation resistance. The preceding drought contributes to the survival of plants in saline or cold conditions.

The process of increasing the sustainability of the body to this environmental factor as a result of adaptation to the factory of other nature is called cross adaptation.

To study the general (non-specific) stability mechanisms. Of great interest is the answer of plants on factors causing water deficiency in plants: for salinization, drought, low and high temperatures and some others. At the level of a whole body, all plants react to water deficit equally. It is characterized by the oppression of the growth of shoots, enhancing the growth of the root system, the synthesis of abscicoic acid, the decrease in the nutritional conductivity. After some time, the lower leaves are rapidly aging, and their death is observed. All these reactions are aimed at reducing water spending due to the reduction of evaporating surface, as well as by increasing the absorption activity of the root.

Specific reactions - This is a reaction to the action of a single stress factor. Thus, phytoaecxins (substances with antibiotic properties) are synthesized in plants in response to contact with pathogens of microorganisms (pathogens).

The specificity or not specificity of response reactions implies, on the one hand, the attitude of the plant to different stressors and, on the other hand, the nature of the reactions of plants of various types and varieties on the same stressor.

The manifestation of specific and nonspecific responses of plants depends on the strength of stress and the rate of its development. Specific responses occur more often if stress develops slowly, and the body has time to restructure and adapt to it. Nonspecific reactions usually occur with a shorter and strong action of the stressor. The functioning of non-specific (general) stability mechanisms allows the plant to avoid high energy costs for the formation of specialized (specific) adaptation mechanisms in response to any deviation from the norm of their habitat conditions.

The stability of plants to stressful exposure depends on the phase of ontogenesis. The most resistant plants and plant organs in a resting state: in the form of seeds, bulbs; Wood perennials - in a state of deep rest after leaffall. The most sensitive plants are in young age, since in the conditions of stress, the growth processes are damaged primarily. The second critical period is the period of formation of weights and fertilization. The action of stress in this period leads to a decrease in the reproductive function of plants and a decrease in the crop.

If stressful conditions are repeated and have a slight intensity, they contribute to the hardening of plants. This basis methods of increasing resistance to low temperatures, heat, salinization, increased maintenance of harmful gas in the air.

Reliability The vegetable organism is determined by its ability to prevent or eliminate failures at different levels of the biological organization: molecular, subcellular, cellular, tissue, organ, organized and population.

To prevent failures in the vital activity of plants under the influence of adverse factors, principles are used redundancy, heterogeneity of functionally equivalent components, reparation systems lost structures.

The redundancy of structures and functionality is one of the main ways to ensure the reliability of systems. Redundancy and reservation has diverse manifestations. At the sub-cell level, the redundancy and duplication of genetic material contribute to improving the reliability of the plant organism. This is ensured, for example, a double DNA spiral, an increase in the fluid. The reliability of the functioning of the plant organism in the changing conditions is also maintained due to the presence of various molecules of information RNA and the formation of heterogeneous polypeptides. These include and isoenzymes that catalyzize the same reaction, but differ in their physicochemical properties and the stability of the structure of molecules in the changing conditions of the medium.

At the cell level, an example of redundancy is an excess of cellular organelle. So, it was established that in order to provide a plant with photosynthesis products, there are enough parts of the existing chloroplasts. The remaining chloroplasts as it were in the reserve. The same applies to the total content of chlorophyll. Redundancy is also manifested in a large accumulation of precursors for biosynthesis of many compounds.

At the organizational level, the principle of redundancy is expressed in education and in the time-based bookmark more than it is required to change generations, the number of shoots, flowers, spikelets, in a huge amount of pollen, segments, seeds.

In the population level, the principle of redundancy is manifested in a large number of individuals differing in sustainability to one or another stress factor.

Reparation systems are also operating at different levels - molecular, cellular, organized, population and biosotic. Reparative processes go with the cost of energy and plastic substances, so reparation is possible only while maintaining sufficient metabolic intensity. If the metabolism is terminated, reparation stops. In extreme conditions of the external environment, respiratory preservation is especially important, since it is breathing that provides energy reparation processes.

The reduction capacity of cells of adapted organisms is determined by the resistance of their proteins to denaturation, namely the stability of the relationship, which determine the secondary, tertiary and quaternary structure of the protein. For example, the stability of mature seeds to high temperatures is, as a rule, is due to the fact that after dehydration, their proteins acquire resistance to denaturation.

The main source of energy material as a respiratory substrate is photosynthesis, therefore, the stability and ability of the photosynthetic apparatus is restored after damage depends the cell power supply and related reparation processes. To maintain photosynthesis in extreme conditions in plants, the synthesis of the tilacoid membranes components is activated, the lipid oxidation is braked, the ultrastructure of the plastic is restored.

At the organizational level, an example of regeneration can serve the development of replacing shoots, the awakening of sleeping kidneys during damage to growth points.

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The textbook complies with the Federal State Educational Standard of the Middle (Full) General Education, recommended by the Ministry of Education and Science of the Russian Federation and is included in the federal list of textbooks.

The textbook is addressed to students of grade 11 and is designed to teach the item 1 or 2 hours a week.

Modern design, multi-level issues and tasks, additional information and the possibility of parallel working with an electronic application contribute to the effective learning material learning.


Fig. 33. Winter painting hare

So, as a result of the action of the driving forces of evolution in organisms, adaptation to environmental conditions arise. Fixing in isolated populations of various adaptations may eventually lead to the formation of new species.

Questions for repetition and task

1. Give examples of the adaptability of organisms to the conditions of existence.

2. Why are some animals have a bright, demiscipling color, and others, on the contrary, is a patronage?

3. What is the essence of mimicry?

4. Is the effect of natural selection on animal behavior? Give examples.

5. What are the biological mechanisms for the occurrence of adaptive (hiding and warning) painting in animals?

6. Are physiological adaptation by factors determining the level of adaptability of the body as a whole?

7. What is the essence of the relativity of any adaptation to habitat? Give examples.

Think! Perform!

1. Why is there no absolute adaptation to habitat? Give examples proving the relative nature of any fixture.

2. The cubbies have a characteristic striped color, which disappears with age. Give similar examples of changing the color in adults in comparison with the offspring. Is it possible to consider this regularity common for the whole animal world? If not, for what animals and why is it characteristic?

3. Collect information about animals with warning color living in your area. Explain why the knowledge of this material is important for everyone. Make an information booth about these animals. Take a message on this topic before schoolchildren of junior classes.

Work with computer

Contact your electronic application. Explore the material and follow the tasks.

Repeat and remember!

Human

Behavioral adaptations - congenital unconditional reflex behavior. Congenital abilities exist in all animals, including a person. A newborn baby knows how to suck, swallows and digests food, blinks and sneezes, reacts to light, sound and pain. These are examples unconditional reflexes. Such forms of behavior arose in the process of evolution as a result of adaptation to certain, relatively permanent environmental conditions. Unconditional reflexes are inherited, so all animals are already born with a ready-made complex of such reflexes.

Each unconditional reflex occurs on a strictly defined stimulus (reinforcement): Some - for food, others - on pain, third - on the emergence of new information, etc. Reflex arcs of unconditional reflexes are constant and pass through the spinal cord or brain barrel.

One of the most complete classifications of unconditional reflexes is the classification proposed by Academician P. V. Simonov. The scientist suggested split all the unconditional reflexes into three groups, differing in the features of the interaction of individuals with each other and with the environment. Vital Reflexes (from Lat. Vita - life) are aimed at preserving the life of an individual. Their failures lead to the death of individuals, and for the implementation does not require the participation of another individual of the same species. This group includes food and drinking reflexes, homeostatic reflexes (maintaining a constant body temperature, optimal respiratory frequency, palpitations, etc.), defensive, which, in turn, are divided into passive-defensive (runaway, dragging) and actively Defensive (attack on the threatening object) and some others.

TO zoosocial or role reflexes These options of congenital behavior, which arise when interacting with other individuals of their own species. This is sex, parent-parent, territorial, hierarchical reflexes.

The third group is self-development reflexes. They are not associated with adaptation to a specific situation, but as if turned into the future. Among them are research, imitative and game behavior.

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In the process of evolution as a result of natural selection and struggle for the existence there are devices (adaptation) of organisms to certain habitat. Evolution itself is essentially a continuous process of formation of adaptations originating in the following scheme: intensity of breeding -\u003e Fight for existence -\u003e selective death -\u003e Natural selection -\u003e fitness.

Adaptation affects different sides of the vital processes of organisms and therefore can be several types.

Morphological adaptation

They are associated with changing body structure. For example, the appearance of a membrane between the fingers of the waterfowl (amphibians, birds, etc.), dense cohesion in the northern mammals, long legs and long necks in marsh birds, flexible body at normal predators (for example, caressing) and so on . In warm-blooded animals, when promoting north, there is an increase in the average body sized (Bergman rule), which reduces the relative surface and heat transfer. At the bottom fish, a flat body (skates, flounders, etc.) is formed. The plants in the northern latitudes and high-mountainous areas are frequent, sharpening and pillow-shaped forms, less damage to strong winds and better warmed by the sun in the surround layer.

Protective coloration

The patronizing color is very important for animal species that have no effective means of protection against predators. Thanks to her, animals are becoming less visible on the ground. For example, females of birds, sitting eggs, are almost not distinguishable from the background of the terrain. Bird eggs are also painted under the color of the terrain. Pontrery coloring have bottom fish, most insects and many other animal species. In the north, it is more common to occur white or bright coloring, helping to disguise on the snow (polar bears, polar owls, sands, young laston-bores - Belki et al.). A number of animals appeared painting formed by alternating light and dark lanes or stains, making them less noticeable in shrubs and thick thickets (tigers, young boars, zebras, spotted deer, etc.). Some animals are capable of changing coloring very quickly depending on the conditions (chameleons, octopuses, flabble, etc.).

Disguise

The essence of masking is that the shape of the body and its painting make animals similar to leaves, bitch, branches, bark or spines of plants. It is often found in insects living on plants.

Warning or threatening color

Some types of insects having poisonous or odorous glands have a bright warning color. Therefore, predators, once faced with them, remember this color for a long time and no longer attack such insects (for example, wasps, bumblebees, ladybugs, colorado beetles and a number of others).

Mimicry

Mimicria is the coloring and shape of the body in innocuous animals that imitate them to poisonous fellows. For example, some not poisonous snakes are similar to poisonous. Cicades and crickets resemble large ants. Some butterflies on wings have large spots that resemble eyes of predators.

Physiological adaptation

This type of adaptation is associated with the restructuring of metabolism in organisms. For example, the appearance of warmth and thermoregulation in birds and mammals. In more simple cases, this is a device to certain formats of food, salt composition of the medium, high or low temperatures, humidity or dryness of soil and air, etc.

Biochemical adaptation

Behavioral adaptation

This type of adaptation is associated with a change in behavior in certain conditions. For example, the care of offspring leads to a better survival of young animals and increases the stability of their populations. In the marriage period, many animals form separate families, and in the winter, they are combined in flocks, which makes it easier for food or protection (wolves, many species of birds).

Adaptations to periodic environmental factors

This is an adaptation to the factors of a medium that has a certain frequency in its manifestation. This type includes daily alternations of periods of activity and recreation, states of partial or complete anabiosis (dropping leaves, winter or summer animal diapauses, etc.), animal migration caused by seasonal changes, etc.

Adaptations to extreme habitat conditions

Plants and animals living in deserts and polar regions also acquire a number of specific adaptations. In cacti, the leaves were transformed into spines (decrease in evaporation and protection against animal remedy), and the stem turned into a photosynthetic organ and a tank. Deserted plants have a long root system, allowing water from high depth. Desert lizards can do without water, going insects and getting water by hydrolysis of their fats. In northern animals, in addition to thick fur, there is also a large supply of subcutaneous fats that reduces the cooling of the body.

The relative nature of adaptations

All devices are suitable only for certain conditions in which they have developed. If these conditions change, adaptation can lose their value or even bring harm to having them to organisms. White painting Zaitsev, who protects them well in the snow, becomes dangerous at low-speed winter or strong thaws.

The relative nature of adaptations is well proved by these paleontology, indicating the extinction of large groups of animals and plants that have not survived the change in living conditions.

Live organisms are adapted to the environmental conditions in which their ancestors lived for a long time. Adaptations to environmental conditions are differently called adaptation. They arise in the process of evolution of the population, forming a new subspecies, view, genus, etc. The population accumulates different genotypes that are manifested in different phenotypes. Those phenotypes that most comply with environmental conditions receive more chances to survive and leave offspring. Thus, the entire population is "saturated" useful for this habitat with adaptations.

In their forms (species) adaptation are different. They may affect the structure of the body, behavior, appearance, biochemistry of cells, etc.. Distinguish the following forms of adaptations.

Adaptation of body structure (morphological adaptation). There are significant (at the level of detachments, classes, etc.) and small (at the level of species). Examples of the first are the occurrence of wool in mammals, the ability to fly in birds, lungs in amphibians. An example of small adaptations is a different structure of beak in nearby bird species that feed in different ways.

Physiological adaptation. This is a restructuring of metabolism. For each type, adapted to its habitat conditions, their features of metabolism are characteristic. So some kinds eat a lot (for example, birds), since their metabolism is quite fast (birds require a lot of energy for flight). Some species can not drink for a long time (camels). Sea animals can drink sea water, while freshwater and ground can not.

Biochemical adaptations. This is a special structure of proteins, fats that give organisms the opportunity to dwell in certain conditions. For example, at low temperatures. Or the ability of organisms to produce poisons, toxins, odorous substances for protection.

Protective coloration. Many animals in the process of evolution acquire such a color of the body, which makes them less visible against the background of grass, trees, soil, i.e., where they live. One that allows you to protect against predators, others - imperceptibly to die and attack. Often, the patrons of mammals and chicks are often patronized. While adult individuals can no longer have a patronage color.

Warning (threatening) color. This color is bright and well memorable. Characteristic for stinging and poisonous insects. For example, birds do not eat OS. After trying once, they remember the characteristic color of the wasp for life.

Mimicry - external similarity with poisonous or stained species, dangerous animals. Allows you to avoid eating predators, which "seems" that there is a dangerous look. So mugh-bullies look like bees, some unseated snakes on poisonous, on the wings of butterflies can be patterns, similar to the eyes of predators.

Disguise - similarity of the body shape of the body with an object of inanimate nature. It does not only arise a patronage color, but the body itself resembles an object of inanimate nature in its form. For example, a branch, a sheet. Masking is mainly characteristic of insects.

Behavioral adaptation. Each type of animals forms a special type of behavior that allows you to best adapt to specific habitat conditions. This is the stock of feed, care for the offspring, marriage behavior, hibernation, hopping before attacking, migration, etc.

Often different adaptations are interconnected. For example, patronessing can be combined with a fading of an animal (with behavioral adaptation) at the time of danger. Also, many morphological adaptations are due to physiological.