The mechanism of adaptation to the environment in animals and plants. Adaptation of organisms to their environment Key words habitat body shape adaptation

The aquatic environment is significantly different from the terrestrial one. It has special temperature and light regimes, different gas and mineral compositions, and a different density of the medium.

Light and depth

There is always less light in a body of water than on land, since some of the sun's rays are reflected from the water surface, while others are absorbed by its thickness. The intensity of light penetrating into a body of water depends on the transparency of the water. Thus, in oceans with high transparency, 1% of radiation reaches a depth of 140 m, and tenths of a percent reaches a depth of 2 meters in small lakes with turbid water. The spectral composition of light also changes with depth. Mainly green rays reach deep layers of water, and blue and violet rays reach even deeper. Submerged plants have to adapt not only to the lack of light, but also to changes in its composition by producing additional pigments. It is known that algae living at different depths have different colors: in shallow water zones they predominate green algae, found in deeper brown, and live even deeper red algae. In low-transparent waters, plants are found mainly in the surface layers, and in reservoirs with clear water - at a depth of 100 m or more.

Gas composition of water (oxygen content)

An important factor in the life of aquatic plants is the oxygen content in water. It enters water from the air and is released by plants during photosynthesis. There is usually little oxygen in water, especially at the bottom of a reservoir, where water is not moved by currents, therefore aquatic plants have a developed system of air cavities in all organs

Mineral composition of water

Mineral salts necessary for plant nutrition are contained in water in small quantities. They are absorbed by the entire surface of submerged plants, or their parts. For aquatic plants to absorb dissolved gases and minerals, a large contact surface with the aquatic environment is required. Therefore, the leaves of aquatic plants immersed in water are strongly dissected into narrow thread-like lobes ( hornwort, pemphigus vulgaris -- Utriculariavulgaris, or have a very thin translucent plate (leaves of submerged pondweed). They have a completely undeveloped cuticle and no stomata. Some submerged plants have reduced roots ( hornwort, bladderwort), in others they are poorly developed (Elodea canadensis) and do not play a significant role in the absorption of nutrients. The roots of rooting hydrophytes are weakly branched and without root hairs. At the same time, a number of species have thick and strong rhizomes ( water lily, water lily), which play the role of an “anchor”, a repository of reserve substances and an organ of vegetative propagation.

In plants partially immersed in water, there is a well-pronounced variety of leaves -- difference in the structure of above-water and underwater leaves on the same plant. The former have features common to the leaves of terrestrial plants, the latter have dissected or very thin leaf blades (water lily, egg capsule, arrow leaf, broad-leaved grazing grass - Siumlatifolium)

Density of water

Water differs from air in being more dense, which is reflected in the body structure of hydrophytes. Their mechanical tissues are greatly reduced, since the plants are supported by water itself. Mechanical elements and conductive bundles are often located in the center of the stem or leaf petiole, which gives the ability to bend when water moves.

Submerged hydrophytes have good buoyancy, which is created both by special devices (air chambers, swellings) and by an increase in the surface of the body.

Water temperature

The temperature regime in water is characterized by less heat influx and greater stability. The water slowly heats up and cools down, and this is reflected in the development of plants: hydrophytes awaken in the spring much later than land plants. Daily and annual temperature fluctuations are less than on land. The temperature does not drop below +4 °C.

Reproduction of aquatic plants

The aquatic environment creates specific conditions for seed propagation of plants. The pollen of some hydrophytes is transported by water. Water also plays an important role in the distribution of fruits and seeds, which in many aquatic plants have the ability to remain on the surface of the water for a long time.

Target: to form students’ knowledge about the adaptability of organisms to the environment.

Tasks:

educational: the formation of knowledge about the various ways in which organisms adapt to the environment;

developing: the ability to work with a textbook, analyze, compare, highlight the main thing, think logically

educational: promoting aesthetic education, forming a scientific worldview.

Equipment: table “Adaptability and its relative nature”, photographs, drawings, collections of plant and animal organisms, presentation.

Lesson progress

In the form of a frontal conversation, it is proposed to answer questions.

1. How to explain the adaptability of living beings to their environment?

2. How did the diversity of species existing in nature arise?

3. Why does the organization of living beings increase during evolution?

To the questions: what explanation of the fitness of organisms was common in the 18th century? How did Lamarck explain these phenomena? - students easily give answers, which the teacher summarizes with a remark about the contradictions between scientific facts that reveal the perfection of the organic world and the explanations offered at that time.

Students in groups receive assignments and different objects to work on:

Consider the fruits and seeds of birch, pine, dandelion, poppy, etc. and determine the nature of their adaptability to distribution.

Students record the results of their work in a table.

Each group of students makes a report on the results of their work, showing objects. Generalizations are then made about the variety of adaptations in the same environment based on the findings from the groups.

Much attention should be paid to the explanation of the emergence of adaptations according to Darwin's doctrine of natural selection in comparison with Lamarck's explanation.

It is necessary to ensure that students can correctly explain from the perspective of Darwin’s teaching how this or that device arose.

The description of the formation of long legs and a long neck according to Lamarck and Darwin is read and analyzed.

Students are then asked to explain the occurrence:

• white coloration of polar animals;
• hedgehog quills;
• shells of mollusks;
• wild rose aroma;
• similarities between the moth caterpillar and a twig

When answering, students give explanations of facts based on Darwinian teaching; comparisons with a possible interpretation of the same examples according to Lamarck reveal its ideological essence.

The main attention is paid to elucidating the reasons why Lamarck's theory was powerless to explain the origin of organic evolution, which was brilliantly done by Charles Darwin.

Adaptation, or adaptation, is the ability of an organism to survive and leave offspring in a given environment.

Examples of fitness

TO morphological adaptations include: protective coloring, camouflage, mimicry, warning coloring.

TO ethological or behavioral include threatening postures, stockpiling food.

Physiological adaptation is a set of physiological reactions that underlie the body’s adaptation to changes in environmental conditions and aimed at maintaining the relative constancy of its internal environment - homeostasis.

Chemical interaction (ants secrete enzymes that are used by family members to coordinate activities)

Conservation of water in a cactus

Caring for offspring is a chain of sequential reflexes developed during the process of evolution, ensuring the preservation of the species.

The tilapia fish carries eggs and young fish in its mouth! The fry calmly swim around their mother, swallow something, and wait. But as soon as the slightest danger arises, the mother gives a signal, sharply moving her tail and quivering her fins in a special way, and... the fry immediately rush to the shelter - the mother's mouth.

Some species of frogs carry eggs and larvae in special brood pouches.

In mammals - in the construction of lairs, burrows and other shelters for future offspring, maintaining the cleanliness of the body of the cubs, this instinct, apparently, is characteristic of all mammals without exception.

The origin of adaptations and their relativity

C. Darwin showed that adaptations arise as a result of the action of natural selection. The following examples can serve as proof of the relativity of adaptations:

1) useful organs in some conditions become useless in others: the relatively long wings of swifts, adapted for rapid flight, create certain difficulties when taking off from the ground

2) protective devices from enemies are relative: poisonous snakes (for example, vipers) are eaten by hedgehogs

3) the manifestation of instincts may also be inappropriate: for example, a defensive reaction (releasing a stream of foul-smelling liquid) of a skunk directed against a moving car

4) the observed “overdevelopment” of some organs, which becomes a hindrance for the body: the growth of incisors in rodents when switching to eating soft food.

Students must firmly understand that Darwin's doctrine of relative fitness as a result of natural selection completely refutes idealistic statements about the divine origin and absolute nature of organic purposiveness (C. Linnaeus), as well as about the innate ability of the organism to change under influence only in a direction beneficial to them (Lamarck ).

1. An example of a protective coloring is:

a) the similarity of the shape and color of the body with surrounding objects;

b) imitation of the less protected by the more protected;

c) alternating light and dark stripes on the tiger’s body.

2. The bright coloring of ladybugs, many species of butterflies, some species of snakes and other animals with odorous or poisonous glands is called:

a) camouflage;

b) demonstrating;

c) mimicry;

d) warning.

3. The variety of devices is explained by:

a) only the influence of environmental conditions on the body;

b) interaction of genotype and environmental conditions;

c) only by the characteristics of the genotype.

4. Example of mimicry:

b) bright red color of the ladybug;

c) similarity in the color of the abdomen of the hoverfly and the wasp.

5. Masking example:

a) green coloration of the singing grasshopper;

b) similarity in the color of the abdomen of the hoverfly and the wasp;

c) bright red color of the ladybug;

d) the similarity in color of the caterpillar and moth butterfly with a knot.

6. Any fitness of organisms is relative, because:

a) life ends in death;

b) adaptation is appropriate in certain conditions;

c) there is a struggle for existence;

d) adaptation may not lead to the formation of a new species.

References

1. Mamontov S.G. General biology: Textbook. for students of secondary specialization. textbook institutions – 5th ed., erased. – M.: Higher. school, 2003.
2. General biology: textbook. for students Educated institutions prof. education / V.M. Konstantinov, A.G. Rezanov, E.O. Fadeeva; edited by V.M. Konstantinov. -M.: Publishing Center “Academy”, 2010.

The habitat of living organisms influences them both directly and indirectly. Creatures constantly interact with the environment, receiving food from it, but at the same time releasing the products of their metabolism.

The environment includes:

• natural - appeared on Earth regardless of human activity;
• technogenic - created by people;
• external is everything that is around the body and also affects its functioning.

How do living organisms change their environment? They contribute to changes in the gas composition of the air (as a result of photosynthesis) and take part in the formation of relief, soil, and climate. Thanks to the influence of living beings:

• oxygen content increased;
• the amount of carbon dioxide has decreased;
• the composition of the waters of the World Ocean has changed;
• rocks of organic content appeared.

Thus, the relationship between living organisms and their habitat is a strong circumstance that provokes various transformations. There are four distinct living environments.

Ground-air habitat

It includes air and ground parts and is excellent for the reproduction and development of living beings. This is a rather complex and diverse environment, which is characterized by a high degree of organization of all living things. Soil exposure to erosion and pollution leads to a decrease in the number of living beings. In the terrestrial world, organisms have a fairly well developed external and internal skeleton. This happened because the density of the atmosphere is much less than the density of water. One of the significant conditions for existence is the quality and structure of air masses. They are in continuous motion, so the air temperature can change quite quickly. Living things that live in this environment must adapt to its conditions, so they have developed an adaptation to sudden temperature fluctuations.

The air-terrestrial habitat is more diverse than the aquatic one. Pressure differences are not so pronounced here, but a lack of moisture occurs quite often. For this reason, terrestrial living creatures have mechanisms that help them with the supply of water to the body, mainly in arid areas. Plants develop a strong root system and a special waterproof layer on the surface of the stems and leaves. Animals have an exceptional structure of external integument. Their lifestyle helps maintain water balance. An example would be migration to watering holes. The composition of the air also plays an important role for terrestrial living beings, providing the chemical structure of life. The raw material source for photosynthesis is carbon dioxide. Nitrogen is required to connect nucleic acids and proteins.

Adaptation to the environment

The adaptation of organisms to their environment depends on their place of residence. Flying species have developed a certain body shape, namely:

• light limbs;
• lightweight design;
• streamlining;
• presence of wings for flight.

In climbing animals:

• long grasping limbs, as well as a tail;
• thin long body;
• strong muscles that allow you to pull your body up and throw it from branch to branch;
• sharp claws;
• powerful grasping fingers.

Running living creatures have the following features:

• strong limbs with low mass;
• reduced number of protective horny hooves on the toes;
• strong hind legs and short forelimbs.

In some species of organisms, special adaptations allow them to combine the characteristics of flight and climbing. For example, having climbed a tree, they are capable of long jumps and flights. Other types of living organisms can run fast and also fly.

Aquatic habitat

Initially, the life activity of creatures was associated with water. Its features include salinity, flow, food, oxygen, pressure, light and contribute to the systematization of organisms. Pollution of water bodies has a very bad effect on living creatures. For example, due to a decrease in water levels in the Aral Sea, most of the flora and fauna, especially fish, have disappeared. A huge variety of living organisms live in the expanses of water. From water they extract everything they need for life, namely food, water and gases. For this reason, the entire diversity of aquatic living creatures must adapt to the basic features of existence, which are formed by the chemical and physical properties of water. The salt composition of the environment is also of great importance for aquatic inhabitants.

A huge number of representatives of flora and fauna, which spend their lives in suspension, are regularly found in the thickness of the water body. The ability to soar is ensured by the physical properties of water, that is, the force of buoyancy, as well as by the special mechanisms of the creatures themselves. For example, multiple appendages, which significantly increase the surface of the body of a living organism compared to its mass, increase friction with water. The next example of inhabitants of an aquatic habitat is jellyfish. Their ability to stay in a thick layer of water is determined by the unusual shape of the body, which looks like a parachute. In addition, the density of water is very similar to the density of the body of a jellyfish.

Living organisms whose habitat is water have adapted to movement in different ways. For example, fish and dolphins have a streamlined body shape and fins. They are able to move quickly thanks to the unusual structure of the outer integument, as well as the presence of special mucus, which reduces friction with water. In certain species of beetles that live in an aquatic environment, the exhaust air released from the respiratory tract is retained between the elytra and the body, thanks to which they are able to rapidly rise to the surface, where the air is released into the atmosphere. Most protozoa move using cilia that vibrate, for example, ciliates or euglena.

Adaptations for the life of aquatic organisms

Different habitats for animals allow them to adapt and exist comfortably. The body of organisms is able to reduce friction with water due to the characteristics of the cover:

• hard, smooth surface;
• the presence of a soft layer present on the outer surface of the hard body;
• mucus.

Limbs represented:

• flippers;
• membranes for swimming;
• fins.

The shape of the body is streamlined and has a variety of variations:

• flattened in the dorso-abdominal region;
• round in cross section;
• laterally flattened;
• torpedo-shaped;
• teardrop-shaped.

In an aquatic habitat, living organisms need to breathe, so they developed:

• gills;
• air intakes;
• breathing tubes;
• bubbles that replace the lung.

Features of habitat in reservoirs

Water is able to accumulate and retain heat, so this explains the absence of strong temperature fluctuations, which are quite common on land. The most significant property of water is the ability to dissolve other substances in itself, which are subsequently used both for respiration and for nutrition by organisms living in the water element. In order to breathe, oxygen is necessary, so its concentration in water is of great importance. The water temperature in the polar seas is close to freezing, but its stability has allowed the formation of certain adaptations that ensure life even in such harsh conditions.

This environment is home to a huge variety of living organisms. Fish, amphibians, large mammals, insects, mollusks, and worms live here. The higher the temperature of the water, the less diluted oxygen it contains, which dissolves better in fresh water than in sea water. Therefore, few organisms live in tropical waters, while polar waters contain a huge variety of plankton, which is used as food by fauna, including large cetaceans and fish.

Breathing is carried out over the entire surface of the body or through special organs - gills. For successful breathing, regular renewal of water is required, which is achieved by various vibrations, primarily by the movement of the living organism itself or its adaptations, such as cilia or tentacles. The salt composition of water is also of great importance for life. For example, mollusks and crustaceans require calcium to build their shells or shells.

Soil environment

It is located in the upper fertile layer of the earth's crust. This is a rather complex and very important component of the biosphere, which is closely connected with its other parts. Some organisms remain in the soil their entire life, others - half. For plants, soil plays a vital role. What living organisms have mastered the soil habitat? It contains bacteria, animals, and fungi. Life in this environment is largely determined by climatic factors such as temperature.

Adaptations for soil habitats

For a comfortable existence, organisms have special body parts:

• small digging limbs;
• long and thin body;
• digging teeth;
• streamlined body without protruding parts.

The soil may lack air and be dense and heavy, which in turn has led to the following anatomical and physiological adaptations:

• strong muscles and bones;
• resistance to oxygen deficiency.

The body coverings of underground organisms must allow them to move both forward and backward in dense soil without problems, so the following characteristics have evolved:

• short wool, resistant to abrasion and able to be ironed back and forth;
• lack of hair;
• special secretions that allow the body to slide.

Specific sense organs have developed:

• the ears are small or completely absent;
• no eyes or they are significantly reduced;
• tactile sensitivity has become highly developed.

It is difficult to imagine vegetation without soil. A distinctive feature of the soil habitat of living organisms is that the creatures are associated with its substrate. One of the significant differences in this environment is the regular formation of organic matter, usually due to dying plant roots and falling leaves, and this serves as a source of energy for the organisms growing in it. The pressure on land resources and environmental pollution negatively affect the organisms living here. Some species are on the verge of extinction.

Organismal environment

The practical impact of humans on the environment affects the size of animal and plant populations, thereby increasing or decreasing the number of species, and in some cases, their death. Environmental factors:

• biotic - associated with the influence of organisms on each other;
• anthropogenic - associated with human influence on the environment;
• abiotic - refers to inanimate nature.

Industry is the largest sector that plays a vital role in the economy of modern society. It affects the environment at all stages of the industrial cycle, from the extraction of raw materials to the disposal of products due to their further unsuitability. The main types of negative impact of leading industries on the environment of living organisms:

• Energy is the basis for the development of industry, transport, and agriculture. The use of almost every fossil (coal, oil, natural gas, wood, nuclear fuel) negatively affects and pollutes natural systems.
• Metallurgy. One of the most dangerous aspects of its impact on the environment is considered to be the technogenic dispersion of metals. The most harmful pollutants are: cadmium, copper, lead, mercury. Metals enter the environment at almost all stages of production.
• The chemical industry is one of the dynamically developing industries in many countries. Petrochemical production emits hydrocarbons and hydrogen sulfides into the atmosphere. The production of alkalis produces hydrogen chloride. Substances such as nitrogen and carbon oxides, ammonia and others are also released in large volumes.

In conclusion

The habitat of living organisms influences them both directly and indirectly. Creatures constantly interact with the environment, receiving food from it, but at the same time releasing the products of their metabolism. In the desert, the dry and hot climate limits the existence of most living organisms, just as in the polar regions, only the hardiest representatives can survive due to the cold. In addition, they not only adapt to a particular environment, but also evolve.

Plants release oxygen and maintain its balance in the atmosphere. Living organisms influence the properties and structure of the earth. Tall plants shade the soil, thereby helping to create a special microclimate and redistribute moisture. Thus, on the one hand, the environment changes organisms, helping them improve through natural selection, and on the other, the species of living organisms change the environment.

One of the results, but not the natural guiding driving force of the process, can be called the development in all living organisms - adaptations to the environment. C. Darwin emphasized that all adaptations, no matter how perfect they are, are relative. Natural selection shapes adaptation to specific conditions of existence (at a given time and place), and not to all possible environmental conditions. The variety of specific adaptations can be divided into several groups, which are forms of adaptation of organisms to the environment.

Some forms of adaptation in animals:

Protective coloration and body shape (camouflage). For example: grasshopper, white owl, flounder, octopus, stick insect.

Warning coloring. For example: wasps, bumblebees, ladybugs, rattlesnakes.
Intimidating behavior. For example: bombardier beetle, skunk or American stink bug.

Mimicry(external similarity of unprotected animals with protected ones). For example: the hoverfly looks like a bee, harmless tropical snakes look like poisonous snakes.
Some forms of adaptation in plants:

Adaptations for extreme dryness. For example: pubescence, accumulation of moisture in the stem (cactus, baobab), transformation of leaves into needles.
Adaptations to high humidity. For example: large leaf surface, many stomata, increased evaporation intensity.
Adaptation to insect pollination. For example: bright, attractive color of a flower, presence of nectar, smell, flower shape.
Adaptations for wind pollination. For example: the stamens with anthers are carried far beyond the flower, small, light pollen, the pistil is heavily pubescent, the petals and sepals are not developed, and do not interfere with the wind blowing other parts of the flower.
Adaptability of organisms - the relative expediency of the structure and functions of the organism, which is the result of natural selection, eliminating individuals unadapted to the given conditions of existence. Thus, the protective coloring of the brown hare in the summer makes it invisible, but unexpectedly fallen snow makes this same protective coloring of the hare inappropriate, since it becomes clearly visible to predators. Wind-pollinated plants remain unpollinated in rainy weather.

Plants and animals are amazingly adapted to the environmental conditions in which they live. The concept of “adaptability of a species” includes not only external characteristics, but also the correspondence of the structure of internal organs to the functions they perform (for example, the long and complex digestive tract of ruminants that eat plant foods). The correspondence of the physiological functions of an organism to its living conditions, their complexity and diversity are also included in the concept of fitness.

For the survival of organisms in the struggle for existence, adaptive behavior is of great importance. In addition to hiding or demonstrative, scaring behavior when an enemy approaches, there are many other options for adaptive behavior that ensure the survival of adults or juveniles. Thus, many animals store food for the unfavorable season of the year. In the desert, for many species, the time of greatest activity is at night, when the heat subsides.

In most cases, the color of the body of animals matches the color of the environment in which they live, or is close to it (Fig. 32). Typically, animals of desert zones - turtles, lizards, snakes - have a color close to the color of sand, and northern animals - bear, partridge, fox - are white; praying mantises and dragonflies living among green plants are green in color; The color of the cabbage butterfly caterpillar does not differ from the color of the cabbage leaf on which it feeds. As the color of the environment changes seasonally, the color of the animals also changes. For example, foxes, hares, partridges and ermines living in the European zone have one color in winter and another color in summer.

Disguise- the shape and color of the body of animals, reminiscent of the leaves, branches, buds of plants that surround them and protects them from enemies.

The shape and color of the body of animals sometimes resemble the leaves, branches, buds, and plants that surround them. For example, the chupchik insect resembles a thin twig in its shape and color, the needle fish resembles algae, the seahorse, and the rag fish resembles underwater plants (Fig. 33). Some mollusks look like tree buds. The callima butterfly, widespread in the Malay Archipelago, has wings that are very similar in shape, patterns and veins to leaves.

Some animals have multi-colored, eye-catching bright colors. May beetles, ladybugs, bumblebees, wasps, and most butterflies seem to “warn” their enemies with their colors. Typically, animals with warning coloration have additional means of protection against enemies. These include unpleasant odors or toxic liquids they produce, bristles and needles on the body.

Mimicry(from English mimicry - imitation) - imitation of the color and shape of well-protected, rarely exterminated animals by some defenseless and edible animals (Fig. 34).

In some cases, animals, trying to protect themselves from enemies, imitate the shape and color of the animals' bodies with warning coloring. An example of mimicry is the similarity in color of some flies with wasps, cockroaches with ladybugs, non-venomous snakes with poisonous ones, and certain types of butterflies with wasps and bumblebees. It should be noted that the protective and warning coloration of animals becomes more effective in combination with their behavior. For example, the color of the plumage of the bittern that lives in the reeds is similar to the color of the reeds. Despite this, as danger approaches, she stretches her neck and, raising her beak upward, stands motionless. In this position, she becomes invisible to the enemy.

Imitation of color and shape is inherent not only in the organisms themselves, but even in their eggs. Thus, the cuckoo does not build nests for laying eggs, like other birds, but throws them into the nests of small birds - thrush warbler, garden warbler, redstart. It is interesting that before laying her eggs, she examines the eggs in the nests of these birds and lays ones that are exactly the same in color and size (Fig. 35).

Reproduction devices

There are also adaptations of animals associated with the need to leave offspring. For example, the females of some insects attract males with the help of a smell secreted by glands located on their bodies.

Caring for offspring

Some adaptations are associated with nursing offspring. For example, the American catfish carries its eggs attached to its belly. The midwife toad carries fertilized eggs on her back until young toads emerge from them. Unlike lower vertebrates, birds lay eggs in specially built nests and warm them with their bodies. After the chicks hatch from the egg, they continuously feed and protect them from enemies. Adaptations associated with caring for offspring are especially highly developed in mammals.

Species devices

In addition to adaptations in individual organisms, there are also adaptations within species. An example of such adaptations are adaptations related to nutrition, reproduction, leaving offspring, protection from enemies, and overcoming adverse weather conditions in organisms living in groups. Material from the site

Environmental factors

For the normal functioning of life in animals, in the process of evolution, vital adaptations appeared depending on abiotic environmental factors and their seasonal changes in nature:

Pictures (photos, drawings)

• Rice. 32. Protective coloration of animals: 1 - green grasshopper; 2 - caterpillar of a moth butterfly; 3 - tree frog; 4, 5 - plumage of partridge in summer and winter; 6 - nightjar; 7, 8 - ermine in summer and winter

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  Rice. 33. Animal camouflage: 1 - mantis; 2 - chupchik; 3 - bittern; 4 - seahorse; 5 - rag fish; 6 - sea “clown”; 7 - needle fish

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  Rice. 34. Warning coloration and the phenomenon of mimicry in animals: 1 - white butterfly; 2 - poisonous heliconius butterfly; 3 - glass; 4 - buzzer fly; 5 - common wasp; 6 - poisonous coral adder; 7 - non-venomous American grass snake; 8 - ladybug; 9 - cockroach

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