In mammals, the spine is divided into five sections: cervical, thoracic, lumbar, sacral, and caudal. Only cetaceans do not have a sacrum. The cervical region almost always consists of seven vertebrae. Thoracic - from 10-24, lumbar from 2-9, sacral from 1-9 vertebrae. Only in the caudal region, their number varies greatly: from 4 (in some monkeys and humans) to 46.
Real ribs articulate only with the thoracic vertebrae (rudimentary may be on other vertebrae). In front, they are connected by the sternum, forming the chest. The shoulder girdle consists of two shoulder blades and two collarbones. Some mammals do not have clavicles (ungulates), in others they are poorly developed or replaced by ligaments (rodents, some carnivores).
The pelvis consists of 3 pairs of bones: iliac, pubic and ischial, which are tightly fused together. Cetaceans do not have a true pelvis.
The forelimbs serve as mammals for movement on the ground, swimming, flight, grasping. The humerus is greatly shortened. The ulna is less developed than the radius and serves to articulate the hand with the shoulder. The hand of the forelimb consists of the wrist, metacarpus and fingers. The wrist consists of 7 bones arranged in two rows. The number of metacarpus bones corresponds to the number of fingers (no more than five). The thumb consists of two joints, the rest - of three. In cetaceans, the number of joints is increased.
In the hind limbs, the femur in most mammals is shorter than the tibia.
The respiratory system of mammals consists of the larynx and lungs. The lungs are distinguished by a large branching of the bronchi. The thinnest of them are the bronchioles. At the ends of the bronchioles are thin-walled vesicles (alveoli), densely braided with capillaries. The diaphragm is a characteristic anatomical feature of mammals. Plays an important role in the process of respiration.
The kidneys in mammals are bean-shaped and located in the lumbar region, on the sides of the spine. In the kidneys, as a result of blood filtration, urine is formed, then it flows down the ureters into the bladder. Urine comes out of it through the urethra.
In mammals, the forebrain and cerebellum are especially developed. The cerebral cortex is formed by several layers of nerve cell bodies and covers the entire forebrain. It forms folds and folds with deep furrows in most mammalian species. The more folds and convolutions, the more complex and diverse the behavior of the animal. Also, mammals have a well-developed peripheral nervous system, which provides them with the highest speed of reflexes. The sense organs include: organs of vision, organs of hearing, organs of smell. The organs of vision are of great importance in the life of mammals. Unlike birds, each eye of which sees objects separately, mammals have binocular vision. The auditory organs contain the external auditory meatus and the auricle. The olfactory organs are located in the anterior and posterior sections of the nasal cavity.
Digestive system mammals is a gastrointestinal tract - a tube connecting the mouth to the anus. The digestive system includes: oral cavity, salivary glands, pharynx, esophagus, stomach, intestines, anus.
Most mammals have teeth (except monotremes, some cetaceans, pangolins and anteaters). They are found in the cells of the jaw bones. There are four types of teeth: incisors, canines, false-rooted and true molars.
After entering the oral cavity, the food is chewed by the teeth. Then the food is moistened with saliva, which flows through the ducts from the salivary glands. This makes it easier to swallow and move down the esophagus. Under the influence of saliva, complex carbohydrates (starch, sugar) contained in food are converted into less complex ones. The salivary glands are highly developed in herbivores. A cow, for example, secretes 60 liters of saliva per day. In most animals, saliva has pronounced antiseptic properties.
The esophagus ensures that the food bolus enters the stomach.
Most mammals have a single chamber stomach. In its walls are glands that secrete digestive juice. But herbivorous mammals, such as deer, cow, goat, sheep, etc., have a multi-chambered stomach. The intestine is divided into thin and large. The small intestine includes the duodenum, jejunum, and ileum. To the thick - the cecum, colon and rectum.
In the small intestine, food is digested under the influence of digestive juices. They are secreted by the glands of the intestinal walls, as well as by the liver and pancreas, which open into the initial section of the small intestine - the duodenum. Nutrients in the small intestine are absorbed into the blood, and the remains of undigested food enter the large intestine.
At the junction of the small and large intestines, there is an ileocecal valve that prevents the forming feces from being thrown back into the small intestine. In the caecum, under the influence of bacteria, there is a change in indigestible food substances. Also, in most mammals, there is a large amount of lymphatic tissue in the walls of the caecum, which makes it an important organ of the immune system. In many animals (for example, rabbits, beavers), the caecum is large. In some animals, it happens with an appendix. In the colon, the feces are dehydrated, accumulate in the rectum, and then are expelled out through the anus.
I must have been skipping biology class just when my classmates were studying mammals. Because for a long time I could not clearly answer even myself who belongs to this class. I felt ashamed, and I began to make up for the lost program.
Who are mammals
Mammals are those living organisms that feed their offspring with their milk. The class of mammals is incredibly huge and contains more than 5,000 species. Mammals can live:
- on the land;
- in water;
- underground;
- in the air.
Mammals can be domestic and wild. They can also adapt to any climatic conditions. To do this, nature to help gave them the opportunity to maintain body temperature by sweating or evaporating through the mucous membranes (we saw how dogs breathe through their mouths when it's hot). And in the cold season they are protected by wool, fur or hair. For comparison, in reptiles and fish, scales serve for these purposes, and in birds, feathers.
For clarity, I will give an example of those animals that are mammals: dogs, cats, kangaroos, hedgehogs, elephants, the bats, whales, giraffes, rodents, hares, monkeys, horses, lions, wolves.
In 1996, the first cloned mammal, Dolly the sheep, was born. She lived only 7 years.
By the way, people also belong to the class of mammals.
A hallmark of mammals
All animals belonging to the class of mammals have developed all the senses: sight, smell, hearing, touch, taste. Also, mammals have a good memory, are capable of analyzing their actions, are able to distinguish colors and always recognize themselves in the mirror.
One more interesting feature this group is the presence of claws. Note that the hooves of horses and cows are also claws. Only modified ones. Claws help animals to get food, climbing trees and rocks, to defend themselves from enemies (by striking with a hoof or a sharp fingernail).
And for such bulky animals as an elephant, a rhinoceros and a hippopotamus, a horn shoe (hoof-claw) serves as a kind of “hook” when climbing a mountain path.
mammals can be defined as a group of hairy vertebrates that feed their young with milk and have a unique mandibular articulation. And yet this definition fails to convey them amazing features, unique adaptations, complex behavior and fine organization of communities.
More precisely, the essence of mammals reflects the diversity of their structural and functional organization, as well as the special flexibility of behavior. The tiny ferocious bat weighs 1.5 g, and the mass of the blue minke whale is 100 million times greater. The fodder plot of a wolf can cover 1000 square meters. km, while a naked mole rat never leaves its hole. The female of this rodent gives birth to up to 28 cubs, and the orangutan - only one. An elephant, like a man, lives for about 70 years, while the male marsupial mouse never meets a second spring and dies before the birth of its first and only offspring. No facet of this diversity arises by chance: mammals are diverse, but not infinite.
There are about 4,680 species of mammals (modern molecular studies are discovering many new ones), which, on the basis of family relationships, are divided into 1,100 (or so) genera, 139 families, 18 orders, and 2 subclasses. These subclasses mean 200 million years of separate evolution of oviparous Prototheria and viviparous Theria; in turn, within the limits of viviparous 90 million years, marsupials are separated from placentals. Some evolutionary events in placental history may be almost as ancient.
Even within the divisions of the class recognized by taxonomists, there is striking diversity in size, structure, and mode of life. Indeed, it is typical for mammals that members of the same species can behave differently depending on the environment.
Placental mammals are now thought to fall into four groups: Xenarthra, Afrotheria, Laurasiatheria and Euarchonta+Glires. Each of the first three groups almost certainly descended from a common ancestor (monophyletic), however, it is suspected that Euarchonta and Glires may have different roots (paraphyletic).
Class Mammals(MAMMALIA)2 subclasses, 27 orders, 139 families |
Lagomorphs, order Lagomorpha 87 species, 12 genera, 2 families |
| Elephant jumpers, order Macroscelidea 15 species, 4 genera, 1 family |
|
| Insectivora, order Isectivora (Lipotyphla) 424 species, 67 genera, 6 families |
|
| Carnivores, detachment Carnivora 231 species, 95 genera, 9 families |
Bats, order Chiroptera 977 species. 174 genera, 18 families |
| Seals and sea lions, order Pinnipedia (Carnivora) 33 species, 21 genera, 3 families |
Teeth, order Xenarthra 29 species, 13 genera, 4 families |
| Whales and dolphins, order Cetacea 88 species, 40 genera, 14 families |
Pangolins, Order Pholidota 7 species, 1 genus, 1 family |
| Dugongs and manatees, order Sirenia 4 species, 2 genera, 2 families |
Infraclass METATHERIA (marsupials) |
| Primates, order Primates 256 species, 64 genera, 13 families |
American opossums, order Didelphimorphia 63 species, 13 genera, 1 family |
| Tupai, order Scandentia 18 species, 6 genera, 1 family |
Coenoles, order Paucituberculata 5 species, 3 genera, 1 family |
| Wormwings, order Dermoptera 2 species, 1 genus, 1 family |
Microbiotheria, detachment Microbiotheria 1 species and genus (Dromiciops australis), 1 family |
| Proboscis, order Proboscidea 2 species, 2 genera, 1 family |
Carnivorous marsupials, order Dasyuromorphia 72 species, 17 genera, 2 families |
| Hyraxes, order Hyracoidea 11 species, 3 genera, 1 family |
Marsupial moles, order Notoryctemorphia 2 species, 1 genus, 1 family |
| Aardvarks, order Tubulidentata 1 species and genus (Orycteropus cafer), 1 family |
Bandicoots, order Peramelemorphia 18 species, 7 genera, 2 families |
| Odd-toed ungulates, order Perrissodactyla 16 species, 6 genera, 3 families |
Diprotodontia order Diprotodontia 128 species, 39 genera, 10 families |
| Artiodactyls, order Artiodactyla 196 species, 82 genera, 10 families |
Subclass PROTOTHERIA (oviparous) |
| Rodents, order Rodentia 1999 species, 431 genera, 28 families |
Monotremes, order Monotremata 3 types. 3 genera, 2 families |
The ancestors of ancient mammals were animal-toothed reptiles. They are so named because they had a structure of teeth similar to mammals. In the course of evolution, a group of small animals separated from them, outwardly resembling egg-laying ones. In the process of natural selection, these animals developed a more developed brain, and, consequently, they were characterized by more complex behavior. At the end of the Mesozoic, after the extinction of the dinosaurs, ancient mammals settled in various habitats in terrestrial ecosystems.
Representatives of the class Mammals, or Beasts, are higher vertebrates, warm-blooded animals, whose body is covered with wool. Animals give birth to cubs and feed them with milk. They have a large brain with well-developed forebrain hemispheres. They are characterized by care for offspring and the most complex behavior. In the process of evolution, mammals have reached a huge diversity in connection with the formation of adaptations to different living conditions. About 4,000 are known. modern species.
When determining mammals, one should pay attention to: the color of the fur, the shape of the body and head, the length of the body and tail.
- Animals hunting at night usually have large eyes.
- Some animals have large ears to hear better.
- Wool allows the mammal to keep warm; in addition, coloring helps to hide from the eyes of enemies.
- The tail helps the animal to maintain balance. In different animal species, tails vary in length and thickness.
- Most animals have a great sense of smell.
- The shape of the teeth depends on the food to which the animal is accustomed.
- The mustache helps the animal find its way, especially in a dark note.
- The mammary glands produce milk for offspring.
- Powerful aromatic glands under the tail allow the beast to mark the territory.
- The number of fingers on the paws different types different, so the animal is easy to identify by the trail.
The body of mammals consists of a head, neck, trunk, tail and two pairs of limbs. On the head, the facial and cranial regions are distinguished. In front is a mouth surrounded by soft lips. The eyes are protected by movable eyelids. Only mammals have an outer ear - the auricle.
The body of mammals is covered with hair, which reliably protects against sudden changes in temperature. Each hair grows from a hair follicle embedded in the skin. Hair, claws, nails, horns, hooves come from the same skin buds as reptile scales. The skin of mammals is rich in glands. The secretions of the sebaceous glands, located at the base of the hair, lubricate the skin and hair, making them supple and waterproof. Sweat glands are involved in cooling the body and removing toxic substances. The mammary glands secrete milk.
The limbs of mammals are located not on the sides, as in amphibians and reptiles, but under the body. Therefore, the body is raised above the ground. This makes it easier to move on land.
Musculoskeletal system
The skeleton of mammals, like all terrestrial vertebrates, consists of five sections, but has a number of characteristic features. The skull of the animals is large.
The teeth are differentiated into incisors, canines and molars, they are placed in recesses - alveoli. The cervical spine consists of seven vertebrae. Internal organs protects the chest. sacral department fuses with the bones of the pelvis. The number of vertebrae in the caudal region depends on the length of the tail. The skeleton and the muscles attached to its bones make up a powerful musculoskeletal system, allowing the animal to make many complex movements and move actively.
Respiratory system
In mammals, a diaphragm appears - a muscular septum that separates the chest cavity from the abdominal cavity. Due to it, animals can further reduce or increase the volume chest.
When muscles work intensively, the body requires a large amount of oxygen. In this regard, mammals have well-developed lungs.
Circulatory system
Circulatory system mammals consists of two circles of blood circulation and a four-chambered heart. The movement of arterial and venous blood through the vessels ensures a rapid metabolism, due to which a constant body temperature is maintained.
Digestive system
The digestive system begins with the oral cavity. Here food is crushed, pounded with the help of teeth and moistened with saliva secreted by the salivary glands. In animals that feed on coarse plant foods, the stomach consists of several sections, the intestines are long. Various protozoa that decompose plant fiber live in the stomach and intestines.
In predators, the structure of the stomach is simpler and the intestines are shorter. All mammals have a well-developed liver and pancreas.
excretory system
The excretory organs of mammals are two kidneys. The urine formed in them through the ureters enters the urinary bladder, and from there it is periodically excreted.
Litter
Mammals leave litter in any weather. Litter of predators usually has an oblong shape and contains undigested remains of animals; the droppings of herbivores are most often rounded, with an admixture of plant fibers.
Nervous system
The nervous system, especially the brain, has received a high level of development in mammals. In the forebrain, due to the growth and thickening of the cortex, the large hemispheres developed. In predatory mammals and monkeys, the cortex forms convolutions that increase its area. In this regard, animals have a complex behavior, there is a memory, elements of rational activity. They are able to report their condition, intentions, express emotions. The degree of development of the sense organs depends on the lifestyle and habitat of a particular species.
The cubs of most animals develop in the mother's body and are born fully formed. The mother feeds them with milk. Mothers, and sometimes fathers, look after the growing generation and protect it until the cubs can fend for themselves. Cats, foxes and other predators teach their offspring to hunt. In small mammals, for example, in mice, there are several broods per year; offspring stay with their mother for only a few days, after which they begin an independent life.
breastfeeding
Feeding cubs with milk is a very important feature of mammals. Milk has a high nutritional value and contains all the necessary substances for the growth and development of the cub. The color of milk depends on the amount of fat. Fat is part of the milk in the form of microscopic droplets and therefore is easily digested and absorbed in the baby's body.
Ecological groups of mammals
Adaptation to the environment
Depending on the characteristics of the processes of reproduction and development of mammals, they are divided into two subclasses: First beasts and Beasts.
First beasts
Representatives of the first animals lay eggs, which then incubate ( platypus) or worn in a bag on the belly (echidna). Hatching cubs lick the milk that is secreted on the mother's belly.
Beasts
Animals are divided into infraclasses Inferior, or marsupials, and Higher, or Placental.material from the site
marsupials
Marsupials, distributed mainly in Australia, give birth to small and helpless cubs. They are worn by the female in a bag for several months, attached to the nipple of the mammary gland.
Placental
Placentals have a special organ for the development of a fertilized egg - the uterus. The fetus in it is attached to the wall by the placenta and receives nutrients and oxygen from the mother through the umbilical cord.
Among the placental, a special detachment is distinguished Primates. It includes the most developed representatives of the animal world, most of which are monkeys. Humans are also included in this category.
Role in nature
Representatives of mammals differ from each other in their way of life, the type of food they consume, and therefore perform various functions in ecosystems. Herbivorous mammals are the primary consumers organic matter. Predatory animals contribute to the regulation of the number of herbivorous animals. Many rodents and insectivorous mammals are involved in soil formation. The passages they create in the soil contribute to its enrichment with moisture, air, organic and inorganic substances.
Role in human life
Man began to domesticate mammals and birds about 15 thousand years ago. Probably the first domestic animal was a dog, then a goat, a sheep, and cattle were domesticated. The domestication of animals led to settled life, people began to engage in animal husbandry and agriculture.
Pictures (photos, drawings)
4.91. External structure mammal
4.92. mammalian skeleton
4.93. The circulatory system of a mammal
4.94. Digestive, respiratory and excretory systems of a mammal
4.95. The mammalian brain
4.96. Expression of emotions in a mammal
4.97. Representatives of mammals: a) first beasts (echidna); b) lower beasts- marsupials (kangaroos)
4.98. Supposed appearance ancient mammal
Family and home - women's magazine Owoman.ru » Encyclopedia for a child from A to Z
What animals belong to the class Mammals?
Mammals are among the vertebrates. They live in a variety of different conditions, and the number of their species exceeds all other animal species.
All mammals are warm-blooded animals. This means that they can keep warm and live in the coldest conditions. Most of them have hair or fur. Unlike other animals, young mammals feed on mother's milk. In addition, mammals have larger brain volume and mass compared to other animals.
Origin and development
The first mammals appeared on Earth about 200 million years ago. These were small animals that fed on insects. When dinosaurs disappeared from the face of the Earth about 65 million years ago, mammals began to master more and more new habitats and adapt to the most diverse poverty, as a result, many new species appeared. Over the course of 50 million years, thousands of species arose and disappeared, but today there are 4,200 different species of mammals on Earth.
Diversity of living conditions
Mammals are not as numerous as birds or fish, but they can be found in almost every corner of the planet: some of them live in the seas and rivers, others live in trees, and still others live on the plains. Some mammals have learned to survive in arid deserts and on snowy, cold mountaintops.
Who needs teeth?
In most mammals, teeth are adapted to the food that makes up their diet. Most herbivores have large, flat teeth. Rodents have sharp teeth, and the front incisors are designed for nuts and other hard foods. At carnivorous predators, such as lions and wolves, have large fangs with which they grab prey, and with their sharp molars they tear off pieces of meat.
Baby care
Mammal cubs during the time they are close to their mother and feed on her milk, learn everything that is useful in their future life. At birth, lion cubs are blind and helpless, weighing only one and a half kilograms.
The mother takes care of them, carries them in her mouth from one shelter to another, and the male protects his family. Only when they are 18-24 months old are the cubs ready to start an independent life.
Who are Mammals?
desert dweller
Bactrian Asian camel - Bactrian, common in Central Asia well adapted to life in the desert. It can go without food and water for many days and even weeks, because food stores are stored in humps. Thick eyebrows and long eyelashes protect the camel's eyes from sand. A camel may even close its nostrils if a sandstorm rises. The closest relative of the Bactrian is the one-humped camel, or dromedary.
Everyone in their own way
Omnivorous mammals, including humans, eat both meat and plant foods. Insectivores, such as shrews and hedgehogs, have many small sharp teeth, while anteaters have no teeth at all: they lick ants with their long, sticky tongue. Some whales also lack teeth: they filter water through a mesh of bone plates (whalebone), leaving a myriad of creatures in their mouths - plankton.
The appearance of offspring
Three types of mammals lay eggs: the platypus and two types of echidnas. They are called oviparous, or monotremes. Others, like kangaroos, possums, koalas and wombats, marsupials. Their cubs are born very tiny and live in a special bag on their stomach until they can take care of themselves. Most mammals, including monkeys, cats and dogs, are placental. (The placenta is a special organ in the wall of the uterus through which nutrients enter the embryo.).
The most numerous
Placental animals make up the most large group mammals. In many of them, the baby can remain inside the mother's body for a very long time. For example, an elephant bears a baby elephant for 22 months, and the baby is born fully formed. In some mammals (horses, giraffes, deer), a newborn can, just a few minutes after birth, already stand up and move independently, but in many others, including humans, the cubs are completely helpless at birth.
The science of classifying animals is called systematics or taxonomy. This science defines family ties between organisms. The degree of relationship is not always determined by external similarity. For example, marsupial mice are very similar to ordinary mice, and tupai are very similar to squirrels. However, these animals belong to different orders. But armadillos, anteaters and sloths, completely different from each other, are united in one squad. The fact is that family ties between animals are determined by their origin. Examining the structure of the skeleton and dental system animals, scientists determine which animals are closest to each other, and paleontological finds of ancient extinct species of animals help to establish more precisely family ties between their descendants. plays an important role in animal taxonomy genetics the science of the laws of heredity.
The first mammals appeared on Earth about 200 million years ago, having separated from the animal-like reptiles. The historical path of development of the animal world is called evolution. In the course of evolution, natural selection took place - only those animals survived that managed to adapt to the conditions environment. Mammals have developed in different directions, forming many species. It so happened that animals with a common ancestor at some stage began to live in different conditions and acquired different skills in the struggle for survival. Their appearance was transformed, from generation to generation, changes useful for the survival of the species were fixed. Animals whose ancestors looked the same relatively recently began to differ greatly from each other over time. Conversely, species that had different ancestors and passed through different evolutionary paths sometimes find themselves in the same conditions and, changing, become similar. Thus, unrelated species acquire common features, and only science can trace their history.
Classification of the animal world
The living nature of the Earth is divided into five kingdoms: bacteria, protozoa, fungi, plants and animals. Kingdoms, in turn, are divided into types. Exist 10 types Animals: sponges, bryozoans, flatworms, roundworms, annelids, coelenterates, arthropods, molluscs, echinoderms and chordates. Chordates are the most advanced type of animal. They are united by the presence of a chord - the primary skeletal axis. The most highly developed chordates are grouped into the vertebrate subphylum. Their notochord is transformed into a spine.
kingdoms
Types are divided into classes.
Total exists 5 classes of vertebrates: fish, amphibians, birds, reptiles (reptiles) and mammals (animals). Mammals are the most highly organized animals of all vertebrates. All mammals are united by the fact that they feed their young with milk.
The mammal class is divided into subclasses: oviparous and viviparous. Oviparous mammals reproduce by laying eggs like reptiles or birds, but the young are suckled. Viviparous mammals are divided into infraclasses: marsupials and placentals. Marsupials give birth to underdeveloped cubs, which are carried for a long time in the mother's brood pouch. In placental, the embryo develops in the womb and is born already formed. Placental mammals have a special organ - the placenta, which exchanges substances between the mother's organism and the embryo during intrauterine development. Marsupials and oviparous do not have a placenta.
Animal types
Classes are divided into squads. Total exists 20 orders of mammals. In the subclass of oviparous - one order: monotremes, in the infraclass of marsupials - one order: marsupials, in the infraclass of placental 18 orders: edentulous, insectivorous, woolly wings, bats, primates, carnivores, pinnipeds, cetaceans, sirens, proboscis, hyraxes, aardvarks, artiodactyls, calluses, lizards, rodents and lagomorphs.
Mammal class
Some scientists distinguish an independent detachment of tupaya from the order of primates, a detachment of jumping birds is isolated from the order of insectivores, and predatory and pinnipeds are combined into one order. Each order is divided into families, families - into genera, genera - into species. In total, about 4,000 species of mammals currently live on earth. Each individual animal is called an individual.
Cats and dogs, elephants and bats, whales and horses, monkeys and humans - we all belong to the zoological class called mammals.
The difference between mammals and all other animals is that their offspring are fed with milk from the mammary glands of females. In most mammals, young are born already fully formed, while birds, for example, lay eggs, from which only then chicks hatch.
A distinctive feature of mammals is hair or wool, completely or partially covering the body of most of them. All of them are warm-blooded, have a four-chambered heart and a diaphragm.
Although the vast majority of mammals live on land, some of them - such as whales and dolphins - live in the water. Many of them live in burrows - for example, moles and many rodents. Others, such as monkeys and squirrels, live in trees. The only flying mammal is the bat.
Scientists have divided mammals into a large number of smaller groups or orders. The lowest of these orders are echidnas and platypuses, or mammals that lay eggs. The next detachment is the detachment of the edentulous. Then there are marine mammals. Then - artiodactyl mammals.
Predatory mammals eat meat, rodents - plant foods. The very name of insectivores suggests that they serve as food.
The highest order is primates, or mammals with nails instead of hooves or claws. Primates include various monkeys and humans.
1. There are mammary glands, they feed the young with milk.
2. Intrauterine development, live birth (except for the first animals).
3. Wool, sweat glands, subcutaneous fatty tissue - provide warm-bloodedness.
4. Differentiated teeth - allow you to grind food in the mouth.
5. Diaphragm (muscle, the border between the chest and abdominal cavity) - is involved in breathing.
Additional features
6. Alveolar lungs - provide the maximum area for gas exchange.
7. Seven vertebrae in the cervical spine.
8. Non-nuclear erythrocytes.
9. Auricle, external auditory canal and three auditory ossicles in the middle ear.
bird signs
10. Warm-bloodedness (body temperature is constant, allows you to remain active regardless of the ambient temperature).
11. Four-chamber heart, complete separation of arterial and venous blood - provides warm-bloodedness.
12. Good development of the brain, thinking, complex behavior - allows you to adapt to changing environmental conditions.
Tests
1. Which of the following features allowed mammals to master a variety of habitats
A) warmth
B) heterotrophic nutrition
B) pulmonary respiration
D) development of the cerebral cortex
2. Man belongs to the class of mammals, since he has
A) fingers have nail plates
B) the limbs are made up of sections
B) four-chambered heart
D) there are sweat and mammary glands
What morphological feature can distinguish mammals from other vertebrates?
A) five-fingered limb
B) hairline
B) having a tail
D) eyes covered with eyelids
4) The main difference between mammals and other vertebrates
A) presence cervical spine
B) two circles of blood circulation
B) breastfeeding babies
D) warm-blooded and four-chambered heart
5. Man belongs to the class of mammals, since he has
A) internal fertilization
B) pulmonary respiration
B) four-chambered heart
D) there is a diaphragm, sweat and mammary glands
6. The human chest cavity is separated from the abdominal cavity
A) pleura
B) ribs
B) peritoneum
D) diaphragm
7. Mammals are different from other vertebrates
A) constant body temperature
B) sexual reproduction
B) the presence of hair
D) the presence of five parts of the brain
8) The diaphragm in the human body is
A) the space between the layers of the pleural cavity
B) connective tissue that separates muscle fibers
B) the muscle that separates the thoracic and abdominal cavities
D) a muscle that provides neck mobility
9) Embryonic development of a person mainly occurs in
A) fallopian tubes
B) oviduct
B) ovary
D) uterus
10. Choose a trait that is present in mammals but absent in birds
A) aperture
B) thinking
B) warmth
D) four-chambered heart
