reptiles- typical terrestrial animals and the main way of their movement is crawling, crouching on the ground. Key Features the structure and biology of reptiles helped their ancestors leave the water and spread widely across the land. These features are primarily internal fertilization And oviposition, rich in nutrients and covered with a dense protective shell, which contributes to their development on land.

The body of reptiles has protective formations in the form scales, dressing them with a continuous cover. The skin is always dry, evaporation through it is impossible, so they can live in dry places. Reptiles breathe exclusively with the help of lungs, which, compared with the lungs of amphibians, have a more complex structure. intensive breathing with lungs became possible due to the appearance of a new part of the skeleton in reptiles - chest. The chest is formed by a series of ribs connected on the dorsal side to the spine, and on the abdominal side to the sternum. The ribs, due to special muscles, are mobile and contribute to the expansion of the chest and lungs during inhalation and their subsidence at the moment of exhalation.

With a change in structure respiratory system closely related changes in blood circulation. Most reptiles have a three-chambered heart and two circles of blood circulation (as in amphibians). However, the structure of the reptile heart is more complex. In his ventricle there is a septum, which, at the moment of contraction of the heart, almost completely divides it into the right (venous) and left (arterial) halves.

Such a structure of the heart and other than in amphibians, the location of the main vessels more strongly delimits the venous and arterial flows, therefore, the body of reptiles is supplied with blood that is more saturated with oxygen. The main vessels of the systemic and pulmonary circulations are typical of all terrestrial vertebrates. The main difference between the pulmonary circulation of amphibians and reptiles is that the skin arteries and veins have disappeared in reptiles and the pulmonary circulation includes only the pulmonary vessels.

About 8,000 are known today existing species reptiles found on all continents except Antarctica. Modern reptiles are divided into groups: primordial lizards, scaly, crocodiles And turtles.

Reproduction of reptiles

Fertilization in land reptiles internal: the male injects spermatozoa into the cloaca of the female; they penetrate the egg cells, where fertilization occurs. In the body of the female, eggs develop, which she lays on land (buries in a hole). Outside, the egg is covered with a dense shell. The egg contains a supply of nutrients, due to which the development of the embryo occurs. Not larvae emerge from the eggs, as in fish and amphibians, but individuals capable of independent life.

Primal Lizard Squad

TO primordial lizards refers to "living fossil" - tuatara- the only species that has survived to our time only on small islands near New Zealand. This is a sedentary animal, leading a predominantly nocturnal lifestyle and appearance lizard-like. Hatteria in its structure has features that make reptiles related to amphibians: the vertebral bodies are biconcave, a chord is preserved between them.

Joy of the scaly

typical representative scaly - quick lizard. Its appearance indicates that it is a terrestrial animal: five-fingered limbs do not have swimming membranes, fingers are armed with claws; the legs are short, in connection with which the body, when moving, seems to be crawling along the ground, now and then in contact with it - groveling (hence the name).

lizards

Although the legs of the lizard are short, it can run fast, nimbly eluding pursuers into its burrow or climbing a tree. This was the reason for her name - nimble. The head of the lizard is connected to the cylindrical body with the help of the neck. The neck is poorly developed, but still gives the head of the lizard some mobility. Unlike a frog, a lizard can turn its head without turning its whole body. Like all land animals, it has through nostrils, and eyes have eyelids.

Behind each eye in a small depression is eardrum connected to the middle and inner ear. From time to time, the lizard protrudes from its mouth a long, thin, forked tongue at the end - the organ of touch and taste.

The body of the lizard, covered with scales, rests on two pairs of legs. The shoulder and thigh bones are parallel to the ground, causing the body to sag and drag along the ground. Attached to the thoracic vertebrae are the ribs that form the rib cage, which protects the heart and lungs from injury.

Digestive, excretory and nervous system lizards are basically similar to the corresponding amphibian systems.

Respiratory organs - lungs. Their walls have a cellular structure, which greatly increases their surface. The lizard does not have cutaneous respiration.

The brain of a lizard is better developed than that of amphibians. Although it has the same five sections, but the hemispheres of the forebrain are larger in size, the cerebellum and medulla oblongata are much more massive.

The quick lizard is very widely distributed from the Black Sea to the Arkhangelsk region, from Baltic Sea to Transbaikalia. In the north, it gives way to a viviparous lizard similar to it, but more adapted to the cold climate. In the southern regions there are many different types lizards. Lizards live in minks, which in summer weather leave in the morning and evening, but no further than 10-20 m from the mink.

They feed on insects, slugs, and in the south - locusts, caterpillars of butterflies and beetles. During the day, one lizard can destroy up to 70 insects, plant pests. Therefore, lizards deserve protection as very useful animals.

The body temperature of the lizard is unstable (the animal is active only in warm time year), it falls sharply even if a cloud runs over the sun. With a longer decrease in temperature, the lizard loses mobility and stops eating. For the winter, she hibernates; can tolerate freezing and cooling of the body to -5 °, -7 ° C, while all the vital processes of the animal are significantly slowed down. Gradual warming returns the lizard to an active life.

In addition to the quick and viviparous lizard, there are many other types of lizards. Distributed in Ukraine and the Caucasus large green lizard: in desert areas - agama lizards with a long flexible and non-brittle tail.

predatory lizard gray monitor lizard desert dweller Central Asia. Its length is up to 60 cm. The monitor lizard eats arthropods, rodents, eggs of turtles and birds. The largest specimens of monitor lizards discovered by scientists herpetologists (a science that studies reptiles) on the island of Komolo reach 36 cm. In the northern regions, a legless lizard is common - spindle.

Chameleons

Chameleons in appearance they resemble medium-sized lizards, with a helmet-like outgrowth on the head and a body compressed from the sides. It is a highly specialized animal adapted to an arboreal lifestyle. His fingers are fused like pincers, with which he tightly wraps around the branches of trees. The long and prehensile tail is also used for climbing. The chameleon has a very peculiar eye structure. The movements of the left and right eyes are not coordinated and independent of each other, which gives some advantages when catching insects. An interesting feature chameleon is its ability to change the color of the skin - a protective device. Chameleons are common in India, Madagascar, Africa, Asia Minor and southern Spain.

snakes

The squamous order, in addition to lizards, includes snakes. Unlike chameleons, snakes are adapted for crawling on their stomachs and for swimming. In connection with wave-like movements, the legs gradually completely lost the role of organs of movement, only some snakes preserved their rudiments (boa constrictor). Snakes move by bending their legless bodies. Adaptability for crawling manifested itself in the structure internal organs snakes, some of them have completely disappeared. snakes don't have Bladder and just one easy one.

They see snakes badly. Their eyelids are fused, transparent and cover their eyes like a watch glass.

Among the snakes there are non-venomous and poisonous species. The largest non-venomous snake - boa- lives in the tropics. There are boas up to 10 m long. They attack birds and mammals, suffocate their prey by squeezing it with their body, and then swallow it whole. Large boas living in tropical forests are also dangerous to humans.

From not poisonous snakes widespread snakes. The common one is already easily distinguished from poisonous snakes by two orange crescent spots on the head and round pupils of the eyes. He lives near rivers, lakes, ponds, eating frogs, and sometimes small fish, swallowing them alive.

Venomous snakes are viper, cobra, or spectacle snake , rattlesnake and etc.

Viper easily recognizable by the long zigzag dark stripe running along the back. In the upper jaw of the viper are two poisonous teeth with tubules inside. Through these tubules, a poisonous liquid secreted by the victim enters the wound. salivary glands snakes, and the victim, such as a mouse or a small bird, dies.

Destroying great amount mice and locusts, vipers are beneficial to man. However, their bites can cause long-term illness and even death in animals and even humans. The venom of snakes such as asian cobra, american rattlesnake.

The wounds formed when a person is bitten by a snake look like two red dots. A painful swelling quickly develops around them, gradually spreading throughout the body. A person develops drowsiness, cold sweat appears, nausea, delirium appear, in severe cases death occurs.

When a person is bitten by a venomous snake, urgent first aid measures must be taken, remove excess poison near the wound with blotting paper, cotton wool or a clean cloth, if possible, disinfect the bite site with manganese solution, strictly protect the wound from contamination, give the victim strong tea or coffee, and ensure peace. Then get him to the hospital as soon as possible for an emergency injection of anti-snake serum. Where there are poisonous snakes, you can not walk barefoot. Care must be taken when picking berries, protecting your hands from snake bites.

Otrad crocodiles

crocodiles- these are large and most highly organized predatory reptiles, adapted to an aquatic lifestyle, live in tropical countries. Nile crocodile spends most of its life in the water, where it swims well, using a strong, laterally compressed tail, as well as hind limbs that have swimming membranes. The eyes and nostrils of the crocodile are elevated, so it is enough for him to put his head out of the water a little and he already sees what is happening above the water, and also breathes atmospheric air.

On land, crocodiles are not very agile and, in case of danger, rush into the water. They quickly drag their prey into the water. These are various animals that the crocodile lies in wait for at watering places. It can also attack humans. Crocodiles hunt mainly at night. During the day, often large and in groups lie motionless on the shallows.

Turtle Squad

Turtles differ from other reptiles in well-developed strong shell. It is formed from bone plates, covered on the outside with horny substance, and consists of two shields: the upper convex and the lower flat. These shields are connected to each other from the sides, and there are large gaps in front and behind the junctions. The head and forelimbs are exposed from the front, and the hind limbs from the back. Almost all aquatic turtles- predators, land - herbivores.

Turtles usually lay hard-shelled eggs on land. Turtles grow slowly, but they are among the centenarians (up to 150 years). There are giant turtles (soup turtle up to 1 m long. Weight - 450 kg. bog turtle- up to 2 m and up to 400 kg). They are commercial objects.

Meat, fat, eggs are used for food, and a variety of horn products are made from the shell. We have one kind of turtle - bog turtle lives up to 30 years. It hibernates for the winter.

Reptiles are the ancient inhabitants of our planet. They differ in classes and types, each of which has distinguishing characteristic. This article will introduce the reader to the environment in which and how the reptile embryo develops.

General information

Reptiles are those that have adapted to life in land conditions. These first terrestrial are characterized by the following features:

  • Reproduction occurs by eggs and on land.
  • Breathing is done with the lungs. Its mechanism is of a suction type, that is, when the reptile breathes, the volume of the chest changes.
  • The presence of horny scales or scutes on the skin.
  • Skin glands are absent in almost all reptiles.
  • Separation of the ventricle of the heart by partitions is complete and incomplete.
  • The reptile skeleton and musculature received progressive development due to an increase in their mobility: the limb belt became stronger and their position in relation to the body and to each other changed. The spine was divided into different sections, and the head became more mobile.

Reptiles today are represented by scattered remains of reptiles that lived on the planet many thousands of years ago. Now there are six thousand species, almost three times more than amphibians.

Reptiles living today are divided into the following orders of reptiles:

  • beakheads;
  • scaly;
  • crocodiles;
  • turtles.

The first species is represented by the only representative - the hatteria, which has resemblance with a lizard, but its structure is different primitive features. The habitat of the hatteria is New Zealand.

crocodiles

This order includes the following types of reptiles: caiman, gharial, nile crocodile. aquatic lifestyles are characterized by high organization, the presence of a four-chambered heart and a septum that separates the toes of the hind legs. Eyes raised high above the muzzle help crocodiles monitor prey.

Females lay eggs on the shore near water bodies, but in a high, unflooded place. Nests are built from nearby materials. Gharials use the sand where they bury their eggs. Tropical crocodiles mix grass and fallen leaves with earth to build a nest.

The female is able to lay up to 100 eggs, which are fertilized by different partners. Laying occurs at night, a few weeks after the mating process. The eggs are large, similar in size to duck eggs.

And where the embryo develops occurs in the egg, which is in the mother's body. During laying, an embryo is already developing in it. The female is always near the nest, protecting future offspring from predators. Three months later, little crocodiles hatch.

Turtles

Turtles belong to this detachment: red-eared, marsh and steppe. Their body is covered with a bony shell, fused with the vertebrae and ribs. The jaws of turtles do not have teeth. Air enters the lungs in the same way as in amphibians.

Turtles build nests before laying. Aquatic reptiles - in the sand on the shore of reservoirs, and land - on the ground, in a dug hole. They no longer show any concern for their offspring.

Many species of turtles mate in April-early May. Only next spring can be expected from birth adapted to life without parents.

Orders of reptiles: scaly

These include lizards:

  • viviparous;
  • yellowbell;
  • iguana.

Almost all of them, except for the yellowbell, have four limbs for movement and eyes protected by eyelids. The eyelids of the reptiles of this order are mobile.

Egg laying time is May-June. The animal acquires a mink or a hole of small depth and places eggs there. They are from 6 to 16 pieces. Egg large. Inside is the yolk, which contains food reserves for the embryo. In lizards, the egg shell is soft, in crocodiles and turtles it is hard.

Snakes are snakes, vipers, muzzles. They are legless reptiles, when moving, their body bends. The structure of reptiles is distinguished by a long spine of the body and the absence of a chest. Snakes have one lung. The shell of the eyes is formed by fused eyelids.

Reptiles have the ability to swallow large prey. This is achieved by movably connected lower jaws. The front teeth of poisonous snakes are endowed with a channel through which the poison enters the victim.

Snakes reproduce sexually. On this basis, they are viviparous and oviparous. In the natural environment, reproduction is seasonal. The gestation period in time for snakes is different. In snake families - 48 days, in pythons - from 60 to 110.

By the end of pregnancy, snakes begin to build nests. Their locations can be small trees, fallen trunks, rodent minks, anthills. The clutch consists of 3-40 eggs. They have an elongated or oval shape - it depends on the type of reptiles.

Almost all types of snakes do not care about their offspring. The exceptions are the four-lane snake, silt snake and King Cobra. They guard the eggs until the snakes appear.

reproduction

It takes place on dry land. Fertilization in reptiles is internal. Their offspring are born in three ways:

  1. Egg production. This is the case when the question of where the reptile embryo develops can be answered - in the egg. natural environment for him are the genital tract of the mother. It receives nutrition from the egg, after the deposition of which the cub develops from the embryo.
  2. Live birth. It is not inherent in all reptiles, but only certain types sea ​​snakes. Where does the reptile embryo develop? It happens in the mother's body. From it he receives everything necessary for his development.
  3. incubation method. It is used to increase the number of some kind of reptile. From turtles and crocodiles, females will be born if the temperature in the incubator is above 30 ° C, and males - if it is lower.

And where does the embryo of reptiles develop in some vipers and viviparous lizards? Here, the eggs in the mother's oviduct are very long. A cub is formed in them, which is immediately born from the mother's body or hatches from an egg after its laying.

reptile eggs

Reptiles evolved on land. Adapting to the land environment, their eggs were covered with a fibrous shell membrane. Modern lizards and snakes have the most primitive forms of egg shells. And in order for the eggs not to dry out, their development takes place in moist soil.

Dense shells perform not only a protective function. They are the first sign of adaptation of eggs for development on land. The stage of larval formation falls out, due to which the nutrient content increases here. Large reptile eggs.

The second stage in the adaptation of eggs for survival and further development in a land environment is the isolation of the protein shell from the walls of the oviduct. It stores the water supplies needed by the embryo. Crocodiles and turtle eggs are covered with such a shell. They have a fibrous shell replaced by a calcareous one. Water supplies do not pass through it, and with such protection from drying out, embryos can develop under any weather conditions.

Yu.Dmitriev

There are still many white spots in the history of reptiles, or reptiles, but we already know the main thing. It is believed that land pioneers - amphibians - appeared at the junction of the Devonian and the Carboniferous period. After leaving the water and acquiring some adaptations for life on land, the first amphibians, apparently, felt good: the climate was even, warm, the air was humid, and there were enough reservoirs. But at the end of the Carboniferous period, significant changes took place on Earth, the climate changed: in a number of places the globe it became hot and dry, at the same time, as evidenced by the annual rings on the trunks of fossil trees, severe and cold winters began. Naturally, the vegetation has also changed. The happy and carefree life of the first amphibians was over. It was necessary to adapt to the new conditions of existence. Part of the amphibians could not adapt and died. Others remained faithful to a semi-terrestrial, semi-aquatic lifestyle and gradually gave rise to modern amphibians. Still others took a decisive and final step on land and remained to master new living conditions.

The most ancient reptiles, extinct, of course, appeared in the middle of the Carboniferous period. And in mesozoic era, which began about 230 million years ago and lasted a little over 160 million years, the ancient reptiles experienced a rapid flowering and reached an unprecedented diversity. Mesozoic means "life in between" in Greek. But it is often called the "age of reptiles", because it was at this time in the history of the Earth that reptiles - the first truly land inhabitants of our planet - finally conquered it, became the full owners of the land. They were no longer so dependent on climatic and weather conditions, they were no longer tied to a specific place of residence - close to a reservoir, they had many advantages over amphibians. And not least due to the fact that they were able to lay eggs that had never been seen before.

Of course, a new miracle of nature - a reptile egg - did not appear immediately, of course, it took millions of years to create and improve it. But in the end, an egg in a dense "package", which was not afraid of drying out, appeared.

We already know that amphibian eggs can only develop in water. In a humid environment, they are protected from drying out. From this environment, the embryos receive the trace elements necessary for successful development. In addition, it is in water or a humid environment that the larval stage of amphibian development takes place. But what if the egg, that is, the egg of an amphibian, is out of water, out of a humid environment? The embryo of an amphibian will not develop in it. What about reptiles? They are all wrong. The egg of reptiles creates everything the necessary conditions for the normal and successful development of the new being. The embryo must be in aquatic environment. And the egg gives him this opportunity: under the shell there is a tiny "Lake". The fetus must be fed. And the egg gives him everything he needs. In other words, the new egg - the egg of reptiles - was already so perfect and adapted for terrestrial living conditions that for many, many millions of years it did not require significant changes. Even modern birds originating from the ancient winged lizards, it is not much different from the egg of the first reptiles. First of all, this applies to eggs that are shelled with surprisingly perfect material, which both protects the embryo from drying out, and protects against mechanical damage, and allows the embryo to breathe, and so on. In fairness, it must be said that not all reptiles have such eggs. There are also less perfect ones covered not with a shell, but with a leathery substance.

Shelled eggs evaporate up to 10 - 15% of moisture, reptile eggs, dressed with a leathery shell, up to 25%. So reptiles still have to hide their clutches from direct sunlight, looking for a more humid environment.

The independence of reptiles from the presence of water bodies allowed them to spread widely around the planet, to master not only unfavorable for life, but also very harsh areas. Adult animals have learned, adapted to endure harsh conditions. However, eggs, even if they are enclosed in such an ideal "package" as a shell, are less resistant to harsh climatic conditions. So some reptiles "found a way out" in the fact that the eggs linger in the mother's oviducts. (Reptiles, as it were, have expanded and improved this method of preserving eggs, which has already been outlined in some amphibians.) In some reptiles, such a delay is so long that not a “full-fledged” egg with a developed embryo is born, but an almost fully formed cub covered with thin film - the remains of the egg shell. "Newborn" immediately breaks it and immediately begins an independent life.

This phenomenon is called ovoviviparity, and not live birth, as it is sometimes erroneously called. After all, the egg in this case only lingers in the oviduct, the embryo develops autonomously, receiving everything it needs not from the mother, but from the same egg. True, among reptiles there are also real livebearers - their embryos really receive nutrients from the mother's body during development. But such cases are quite rare.

Most reptiles lay eggs. This brings reptiles closer to amphibians. But at the same time, it is the egg that is his fundamental difference- sharply separates reptiles and amphibians. Moreover, it led to further fundamental changes, as it made it possible for reptiles to become completely independent of water, to move away from it at a considerable distance. And this, in turn, could not but affect the structure of the respiratory system.

Amphibians, as we know, get a significant part of their oxygen through their skin. But at the same time, unprotected bare skin leads to a large loss of moisture. For reptiles in a hot dry climate, and even far from water, this could be fatal. And they completely "refused" skin breathing. Their skin glands disappeared, the skin was covered with scales, bone plates or other protective devices. The loss of skin respiration was closely associated with fundamental changes - in comparison with amphibian ancestors - of the respiratory apparatus. Amphibians, as a rule, do not have ribs, and if they do, they are very short and imperfect. In any case, they do not have a chest suitable for breathing. Therefore, when breathing (not skin), they first draw air into the mouth, then, "plugging" the mouth opening, "push" it into the throat.

Reptiles already have ribs rib cage. And this gave them the opportunity not to swallow air, but to inhale it.

The circulatory system has changed, the heart has changed. The skeleton and muscles have changed. First of all, because they have changed - and very much! - limbs of reptiles.

Loop-finned fish to a lesser extent, amphibians to a greater extent, but both of them still took their first steps on earth. Reptiles marched across the planet confidently. For this, appropriate means of transportation were also needed. And the reptiles got them. True, later part of the reptiles lost this great conquest. And because of them, the whole class began to be called reptiles, or reptiles.

The first travelers who saw giant tortoises were amazed not only by their size, but also by their "leggedness". Indeed, the slow-moving giant tortoise seems to be moving on huge pillars. The famous American zoologist Archie Carr told how he was surprised when he first saw a crocodile striving for water. The crocodile suddenly turned out to be not only very agile, but also very long-legged. Many lizards move perfectly on their slender long legs, and there are those that, in case of danger, run - and very quickly - only on their hind legs.

But even the reptiles that lost their legs did not lose the ability to actively move around. Suffice it to recall short-legged lizards and snakes, which are much more agile and generally much better adapted to movement than amphibians.

So, the reptiles firmly set foot on land. They also, like amphibians, lay eggs. But amphibians, even if they live on land all the time, lay their eggs mainly in water or in a humid environment. And reptiles, even if they spend most of their lives in the water and are firmly connected with it, lay their eggs only on land.

Reptiles, although they do not have a constant body temperature, are still less dependent on the environment: their skin is covered with protective devices, air humidity is not so important for them, they are not so afraid of heat, dryness, and direct sunlight. Moreover, moving now to the shade, then to heated places, they to some extent maintain a relatively constant temperature of their body.

Reptiles have many "new acquisitions" that put them among the representatives of the animal world at a higher stage of development compared to amphibians.

However, among the reptiles themselves there are a lot of differences. And in appearance, and in the internal structure, and in behavior, and in the way of life. It `s naturally. After all, they happened in different times and from different ancestors. And in the process of development, changes continued: the loss of legs in some, for example, a change in the lungs of others (in most snakes, only one lung is developed, the other is underdeveloped or absent altogether, the same is true for some lizards).

Some reptiles about 300 million years ago began to return to the water again. Perhaps they were prompted by the same reasons that once forced their ancestors to leave the water: the land was already sufficiently populated, competition appeared, enemies appeared. The sea for such "settlers" was a relatively new and relatively untouched world. 100 million years ago there were already many reptiles in the sea. Of course, they began to differ from terrestrial ones - they regained fins, tails, lost or almost lost their neck. But again they did not turn into fish. They still had lungs, like those of land animals, their blood circulation did not become "fishy", and so on.

Yes, reptiles are very diverse. Nevertheless and common features they have a lot. Therefore, they are combined into one class. And since reptiles are still very different, four orders are distinguished in this class.

The order of beakheads has only one (!) species.

The order of turtles now includes about 250 species.

A detachment of crocodiles is the direct descendants of the inhabitants of the Mesozoic. Crocodiles are now known about 25 species.

And, finally, a detachment of scaly ones. These are the most numerous and most diverse reptiles. They now number about 600 species. Scaly include all snakes, lizards, chameleons.

These are the reptiles that now live on our planet. More precisely, known to us now. Surely there are many still unknown to science.

Bibliography

For the preparation of this work, materials from the site were used.

Caring for offspring in reptiles (reptiles).

1. Features of reproduction of reptiles. Reptiles breed by laying relatively large, in comparison with amphibians, eggs in dense shells - either in a leathery elastic film or in a hard shell, like in birds. One female usually lays several clutches during the season. Some reptiles build special nests for laying eggs. These can be holes dug in a suitable place, in which the female lays eggs, and then sprinkles them with sand or earth; or the simplest hiding places like piled up leaves or nesting chambers in a burrow. However, most reptiles do not arrange any special nests, but leave eggs in loose soil, cracks and hollows of trees, in burrows under objects lying on the ground. But at the same time, the female chooses a place where the clutch is most protected from predators, adverse conditions environment and where temperatures and humidity suitable for embryo development are maintained. The incubation of eggs lasts quite a long time, the cubs hatch completely independent and outwardly very similar to their parents. Many lizards and snakes bring live young immediately.

2. Parental behavior of reptiles. Only a few reptiles guard their clutches, and almost none of them care about the fate of the cubs that are born. The only exceptions are crocodiles, which carry hatching crocodiles from the nest into the water. Moreover, many reptile mothers, on occasion, can eat their own offspring.

sea ​​turtles make long-distance migrations for the purpose of breeding on certain parts of the sea coasts. They gather in these places from different regions, often located many hundreds of kilometers away. For example, a green turtle, heading from the coast of Brazil to Ascension Island in Atlantic Ocean, overcomes a distance of 2600 km, fighting currents and maintaining an accurate course. Arriving at the breeding grounds, the turtles mate near the shore. Mating is very fast. The male claws very strongly and pulls the female's shell. On land, the female moves with great difficulty, clumsily pushing her body forward and leaving behind a wide track, similar to the track of a caterpillar tractor. She moves slowly and is completely subordinated to the desire for one single goal - to find a suitable place for masonry. Having got out of the surf line, the female carefully sniffs the sand, then rakes it and makes a shallow hole, in which she then digs a jug-shaped nest with the help of only her hind limbs. The shape of the nest is the same in all species of turtles. During the breeding season, females lay eggs two to five times; in laying from 30 to 200 eggs. Turtles that mate in the sea often start mating again immediately after the female has laid her eggs. Obviously, the sperm must be preserved during the entire period of time between clutches.

There is no parental behavior in turtles; after laying eggs, they go back to the sea, and, having hatched, the cubs make their way from the shore to the water and further without parents.

Crocodiles lay their eggs in peculiar nests made of sand, clay and stones. They carefully guard the "nest", and after hatching the cubs very carefully transfer them to a safer place.

703-01. Are judgments about the signs of reptiles correct?
1. The body of reptiles is covered with thin bare skin that secretes mucus.
2. In snakes and some lizards, the eyelids have grown together and become transparent.
A) only 1 is correct
B) only 2 is true
C) both statements are correct
D) both statements are wrong

Answer

703-02. Reptiles, unlike amphibians, are real land animals, since they
A) have two pairs of lever limbs
B) have a developed nervous system
C) adapted to terrestrial reproduction and development
D) in addition to skin respiration, pulmonary respiration is carried out

Answer

703-03. Fish and reptiles have a similar structure
A) a skeleton
B) circulatory system
B) digestive system
D) respiratory system

Answer

703-04. What feature provides the ability of reptiles to reproduce on land?
A) protection of offspring
B) cold-bloodedness
B) the structure of the egg
D) the number of eggs laid

Answer

703-05. The transition of animals to reproduction on land became possible with the advent of
A) asexual way breeding
B) external fertilization
B) sexual reproduction
D) internal fertilization

Answer

703-06. What respiratory organs are typical for the depicted animal?

A) gills
B) lungs
B) air sacs
D) trachea

Answer

703-07. Ancient reptiles were able to finally switch to a land-air lifestyle because they
A) there was concern for offspring
B) the cells of the body were supplied with mixed blood
B) had an internal bone skeleton
D) internal fertilization appeared

Answer

703-08. What organ system of reptiles is shown in the figure?

A) circulatory
B) respiratory
B) digestive
D) nervous

Answer

703-09. Are the following statements about reptiles correct?
1. Female reptiles lay fertilized eggs with a high yolk content.
2. The development of reptiles occurs with transformation.
A) only 1 is correct
B) only 2 is true
C) both statements are correct
D) both statements are wrong

Answer

703-10. The peculiarity of the structure of the skin in reptiles is
A) total absence skin glands
B) the presence of bone scales
B) the presence of mucous glands
D) the presence of sweat and sebaceous glands

Answer

703-11. Live birth in some species of lizards arose as an adaptation to life in
A) hot climate
B) hollow trees
B) northern latitudes
D) aquatic environment

Answer

703-12. Which of the signs that arose in the ancestors of reptiles allowed reptiles to completely switch to a land way of life?
A) five-fingered limb
B) three-chambered heart
B) the shell of an egg
D) bone skeleton

Answer

703-13. What is characteristic of the animal shown in the picture?

A) gill breathing
B) reproduction in water
B) two-chambered heart
D) fluctuating body temperature

Answer

703-14. In the event of a decrease in air temperature, terrestrial reptiles
A) begin to eat heavily
B) migrate to more favorable areas of the earth
C) do not change their behavior
D) temporarily hibernate

Answer

703-15. Are the judgments about the reproduction of reptiles correct?
1. Fertilization in reptiles is external.
2. Larvae of snakes and lizards do not look like adult animals.
A) only 1 is correct
B) only 2 is true
C) both statements are correct
D) both statements are wrong

Answer

703-16. Indicate what adaptations for reproduction on land arose in reptiles in the process of evolution.
A) external fertilization and a small supply of nutrients in the egg
B) internal fertilization, a large supply of nutrients and dense shells in the egg
C) external fertilization, the absence of a dense shell in the egg
D) a small supply of nutrients in the egg, internal fertilization

Answer

703-17. Are judgments about the life processes of reptiles correct?
1. Breathing of reptiles is carried out with the help of skin and lungs.
2. The organs of reptiles receive blood richer in oxygen than that of amphibians.
A) only 1 is correct
B) only 2 is true
C) both statements are correct
D) both statements are wrong