features of the animal kingdom. Characteristics of the animal kingdom, signs of animals, habitat

All organisms that exist in the biosphere are classified into 3 kingdoms: eukaryotes, prokaryotes and viruses.

Eukaryotes are divided into 3 kingdoms: plants, animals and fungi. Prokaryotes are divided into 3 kingdoms: true bacteria, blue-green bacteria (cyanobacteria), archaebacteria.

Eukaryotes have a separate nucleus, cell organelles: the Golge complex, mitochondria, EPS, ribosomes and lysosomes. Prokaryotes have only one cavity, which is formed by the cytoplasmic membrane. They do not have a true nucleus, there is no nuclear membrane, Golge apparatus and mitochondria, etc. In a prokaryotic cell there is a structure - a nucleosome - a carrier of genetic material. Prokaryotes have a special structural part of the membrane - the cell wall containing peptidoglycan.

The kingdoms in the superkingdom of eukaryotes differ in the type of nutrition.

Animals are holozoic heterotrophs, they receive energy from ready-made organic matter. Autotrophic plants convert solar energy into chemical bond energy. Mushrooms-osmotrophy.

Fungi have a cell wall made of chitin, unlike plants, fungi do not have plastids. The cell wall of fungi has holes, and nuclei can pass from one cell to another. In animals, irritability is regulated by hormones and the nervous system, in plants only by hormones. Animals are able to move, plants are not. Animals have special excretory organs, plants do not. In animals, the whole body grows; in plants, only certain areas grow. Plants have special organelles - plastids and store carbohydrates in the form of starch; Animals do not have plastids and store carbohydrates in the form of glycogen.

Prokaryotes differ in structure: in true bacteria, the shell consists of a capsule (3 layers) of a single or double-layer cell wall and a cytoplasmic membrane. Cyanobacteria have a 4-layer cell wall. Higher bacteria are heterotrophs, cyanide autotrophs.

Brief description of each kingdom. Eukaryotes, animal kingdom. It is characterized by a heterotrophic type of nutrition, the ability to move, the presence of special excretory organs, the ability to grow the whole body and a compact body. Osmoreception is carried out by special structures, irritability is regulated by the nervous system and hormones. Animal cells do not have a rigid cell wall, few vacuoles, no plastids, reserves in the form of glycogen, there are mitochondria and centrioles. Sexual reproduction, parthenogenesis, budding.

plant kingdom. Autotrophs, no ability to move, irritability is regulated by hormones, no excretory organs, osmoreception is not carried out. Body growth is limited to certain areas, the cell contains cellulose as part of its shell, there is a large vacuole, plastids, reserves in the form of starch, there are mitochondria, there are no centrioles, sexual and vegetative reproduction.

Mushroom kingdom. Nutrition is heterotrophic (osmotrophic), the cell wall contains chitin, there are no plastids. The cell wall of fungi has holes, and nuclei can pass from one cell to another. The main structural element is the mycelium, consisting of hyphae filaments, which reproduces by spores.

Prokaryotes. Blue green algae. Autotrophs, cell wall - 4 layers, one of them is peptidoglycan, filamentous and coccoid cells, reserves in the form of glycogen and currency, there is no nucleus, there are gas vacuoles in the cytoplasm, ring chromosomes that do not separate from the membrane, reproduction by division.

true bacteria. Heterotrophs, the genetic material is represented by a circular DNA molecule, the shell is 3 layers: capsule, cell. Wall, cytopl. Membrane. On the surface there are adnexal structures: flagella and villi. Reproduction by binary fission and budding

2. General characteristics of the animal kingdom: features of organization, diversity, systematics, distribution and significance.

The kingdom Animals is divided into the sub-kingdom Protozoa (Single-celled) and the sub-kingdom Multicellular. The basis of the structure of all animals is a cell, consisting of a membrane, cytoplasm and nucleus. The liquid part of the cytoplasm, hyaloplasm, contains organelles that perform certain functions (mitochondria, ribosomes, endoplasmic reticulum, Golgi complex, centrioles, etc.). In unicellular animals, the cell is a whole organism; in multicellular animals, specialization of cells occurs, tissues, organs, and organ systems appear. Systematics of animals is the subject of discussion. Recently, the animals of the Protozoa sub-kingdom are divided into 7 types, the Multicellular sub-kingdoms - into 20 types. Unlike plants, most animals move actively, most multicellular animals have a nervous system. Food. Animals are characterized by a holozoic and heterotrophic type of nutrition, that is, the use of ready-made organic substances that are captured inside the body, and are not absorbed by osmosis. But among unicellular animals there are organisms with a mixed, mixotrophic type of nutrition: in the light they are able to form organic substances using photosynthesis, using the carbon of inorganic compounds (autotrophic nutrition), they can also feed on ready-made organic substances. Breath. The vast majority of animals are aerobic organisms that need oxygen for oxidation processes, but there are organisms that obtain energy through fermentation, they do not need oxygen, these are anaerobic animals. Selection. As a result of vital activity, substances are formed in organisms that are unnecessary for the organism. The excretion of such substances occurs with the help of many organ systems - respiratory, digestive, through the integument, but, in addition, a special excretory system is formed, which is responsible for the excretion of metabolic products (metabolism). reproduction. There are two types of reproduction in animals - sexual and asexual. In various forms of asexual reproduction, there is a rapid increase in the population, but the daughter individuals do not genetically differ (or rarely differ) from the mother organism. During sexual reproduction, each daughter organism has a unique genotype, falls under the control of natural selection, while individuals with the most successful genotypes for specific living conditions survive. This helps to adapt to changing environmental conditions. Manifold. About 1.5 million species of animals are known, the science of taxonomy is engaged in the study of the diversity of animals. The main task of taxonomy is the distribution of species by taxa on the basis of the unity of origin and similarity of structure, that is, their classification. The classification is based on a species, related species are combined into genera, related genera into families, families into orders, orders into classes, classes into types, types into subkingdoms, subkingdoms into a kingdom. Subkingdom of protozoa (single-celled)

Subkingdom of multicellular

All other animals belong to the multicellular kingdom. Recall that plants do not have a sharp line between unicellularity and multicellularity. Multicellularity repeatedly occurs independently of each other in different types of plants. In animals, however, this line is sharply expressed.

Multicellular are divided into four subsections, of which we will mention only three: phagocytella, pre-multicellular and true multicellular.

Phagocytellous - a new supersection of multicellular organisms, identified in 1973 by the Soviet zoologist A.V. Ivanov. In 1877-1880. the outstanding Russian evolutionary biologist I. I. Mechnikov suggested that the common ancestor of multicellular organisms was a hypothetical creature, which he called phagocytella. He suggested that multicellular organisms are descended from colonial flagellates. Feeding of this primary multicellular organism occurs by ingestion of prey by individual cells by the method of phagocytosis. In other words, phagocytella is characterized by intracellular digestion. Cavitary digestion, that is, the appearance of the intestine, according to I. I. Mechnikov, characterizes highly organized multicellular organisms.

In 1971, the German zoologist K. Grell studied the anatomy of the small marine multicellular Trichoplax and showed that Trichoplax should be distinguished as a separate type. In 1973, A. V. Ivanov proved that Trichoplax is very similar to the hypothetical phagocytella of I. I. Mechnikov, and substantiated the need to separate it into a new subsection. The discovery of the phagocytella subsection, consisting of a single lamellar type, is an outstanding discovery in modern biology. Trichoplax differs from all true multicellular organisms in that this creature crawling along the substrate does not have front and rear parts of the body, it is able to move in any direction. However, Trichoplax has differences between the cells of the ventral and dorsal sides. The body of Trichoplax is flattened and covered with flagellated cells.

At premulticellular(they include the only type of sponges) the body consists of many cells. These cells can perform various functions and have different shape. However, similarly shaped cells are not united with each other in tissues. Nervous system is missing- Cells of one type can turn into another type of cell.

About 4,500 species of sessile animals belong to the sponge type, most of which live in the seas.

True multicellular(these include all further types - from coelenterates to chordates) are characterized by the union of cells of various types in tissues. Cells of different types cannot move into each other. There are nerve cells or nervous system. Real multicellular organisms fall into two sections: radially symmetrical, or two-layered, animals and bilaterally symmetrical, or three-layered, animals.

Division Radial. Type Intestinal

Radially symmetrical animals include only one type coelenterates. Their cells are arranged in two layers: the outer layer is formed by the ectoderm, the inner - by the endoderm.

There are about 9,000 species in the coelenterates. These are hydras, jellyfish, sea anemones, corals. Despite the external diversity, the coelenterates have common organizational features:

There is a closed digestive cavity;

There is no anal opening;

The mouth opening is surrounded by radially arranged tentacles;

Most coelenterates are equipped with stinging cells.

This group is mainly represented by marine organisms.

Department Bilaterally symmetrical, or Three-layer

All other types belong to bilaterally symmetrical shapes. Their body consists of three layers: ectoderm, endoderm and mesoderm located between them. Let us name the main types of three-layered animals.

To type flatworms(6500 species) include ciliary worms, flukes, tapeworms. The digestive system is sac-like. There are separate organs (reproduction, digestion) that are not yet united into an organ system.

Type of nemertine(750 species) combines worm-like marine forms. An anal opening and a through digestive tract appear. For the first time, the rudiment of the circulatory system is formed. Thus, digestion is carried out by one organ system, and the distribution of products throughout the body by another. An accumulation of nerve elements appears at the head end of the body. Organs are grouped into organ systems.

Representatives of the type annelids(7000 species) the body is divided into segments. The circulatory and nervous systems are more complex than those of nemerteans. These include earthworms, leeches, many bristle marine worms. Mollusks and arthropods originated from ancient annelids.

Y type arthropods(1000000 species) segmentation is well expressed, the body is dissected into head, chest and abdomen. There is an external chitinous skeleton. Real limbs appear, perfect nervous and circulatory systems, there is a brain and a heart. A striated muscle is formed. These animals came to land and conquered it. Typical representatives:

trilobites (lived in the Paleozoic), crustaceans, spiders, scorpions, flares, centipedes, insects. For type shellfish(112,000 species), it is characteristic that the segmentation of the body in their representatives is lost. The soft body is usually covered with a calcareous shell. Typical representatives: bivalves (toothless, barley), gastropods (snails, pond snails, coils, slugs), cephalopods (octopuses, octopuses, squids). Cephalopods have a very complex brain encased in a cartilaginous capsule; the eyes are similar in structure to the eyes of vertebrates, a complex circulatory system. In terms of organization, cephalopods are superior to insects, their psyche is often compared with the psyche of mammals.

To type echinoderms(4000-5000 species) include starfish, sea urchins, sea cucumbers, sea ​​lilies. These are radially symmetrical animals, but their larvae are bilaterally symmetrical. This feature indicates that radial symmetry arose in them for the second time in connection with the transition to a sedentary or sedentary lifestyle,

According to the peculiarities of embryonic development, echinoderms, pogonophores, chordates differ sharply from other types and form a separate branch of development.

Type of pogonophores(see Fig. 35) has about 100 species. These marine worm-like animals are distinguished by an amazing feature - external digestion. The tentacles release enzymes into the environment, the breakdown of organic substances occurs outside the body of the animal, after which the nutrients are absorbed by the surface of the body.

To type chordates(41,000 species) include lancelets, ascidians, cyclostomes (lampreys), fish, amphibians, reptiles, birds, and mammals. Everyone has. at least in the embryonic state, there is a supporting dorsal string - a chord; internal skeleton. In lower vertebrates (sharks, rays) it is cartilaginous, then bone (from bony fish and higher). The nervous system has the form of a tube located on the dorsal side of the whirligig.

Meaning. Animals play primarily the most important role in the formation of soils, especially invertebrates - insects, mites, nods, earthworms and mollusks. Where there are many soil-forming invertebrates, the vegetation cover of the Earth also develops very well.

In the processes of soil formation, in eating vegetation and processing its remains, and finally, in the pollination of flowering plants and the spread of infections, invertebrates play the main role: arachnids, insects, centipedes, worms, etc. This is due not so much to their exceptional diversity as to their huge number individuals. Indeed, there are a few large animals per 1 km 2 of a forest or steppe, savanna or desert, or in extreme cases hundreds, and their total weight rarely exceeds 1 ton. There are many invertebrates per square kilometer, and their weight can reach tens of tons. And besides, they quickly multiply and develop, processing thousands of tons of food - plants and other organisms or their remains.

10. General characteristics of the type of molluscs

shellfish- a large type of animals in terms of the number of species (130 thousand). They live mainly in the seas (mussels, oysters, octopuses), fresh water bodies (toothless, pond snails) less often in a humid terrestrial environment (grape snail, slugs). The body sizes of adult mollusks range from a few millimeters to 20 m. Most of them are sedentary animals, some lead an attached lifestyle (mussels, oysters), and only cephalopods are able to move quickly in a jet way.

1) body segmentation is not expressed, which is a sign of specialization, since in ancestral forms the body was divided into more or less homogeneous segments; 2) the secondary body cavity is almost completely reduced; it is represented only by the pericardial sac (pericardium) and the cavities of the gonads;

3) the internal space is represented by a cavity corresponding to the primary cavity of the body;

4) in most forms, the body is covered with a shell and consists of an visceral sac, a head and a leg;

5) the muscles of the body are well developed, there is a special organ of movement - the leg; 6) there is a fold of skin hanging from the dorsal side and dressing the body from the sides - a mantle; 7) the central nervous system is well developed, represented by nerve nodes or cords; due to the fact that segmentation of the body is not expressed, there is a concentration of nerve nodes and cephalization (i.e., the concentration of nerve nodes at the head end of the body) 8) noted high level organization of the sense organs; 9) circulatory system of an open type, a real heart is developed, consisting of one, two or four atria and one or two ventricles; 10) the respiratory system is represented by either gills (in aquatic forms) or lungs (in terrestrial gastropods) 11) the digestive system consists of the pharynx, esophagus, stomach and loop-shaped (V-shaped) curved intestine, opening into the mantle cavity with an anus; 12) a distinctive feature is the presence of special digestive glands, of which the largest is the liver; 13) in most mollusks, a special organ is placed in the pharynx - a grater, with which animals grind pieces of food. There is a device for active capture - the jaws, which in some groups are quite strongly developed ,

14) the excretory system is represented by the kidneys, which, on the one hand, open into the cavity of the pericardial sac, and on the other, into the mantle cavity; 15) the reproductive system can be of the hermaphroditic type, but among the molluscs there are also dioecious animals.

The type of mollusk is divided into seven classes: - armored, furrowed, monoplacophores, gastropods, spadefoots, bivalves, cephalopods.

Class gastropods- include grape snail, slugs, pond snail. The body of gastropods is usually asymmetrical. The body usually consists of a head, a leg, an visceral sac, a mantle forming a mantle cavity, and a shell. The shell, as a rule, is well developed, spirally twisted (in most cases to the right. There are three main layers of the shell: - outer, middle, inner.

The foot is usually very well developed, muscular, with a wide sole, which is abundantly moistened with mucus secreted by the skin glands. The head is separate and bears two pairs of tentacles. The upper ones are the organs of vision, as they end with the eyes, and the lower ones are the organs of touch. The mouth opening is also located on the head. Some gastropods have an operculum on the upper side of the leg that, in case of danger, closes the mouth of the shell. Nervous system it can be either a stem type (in lower forms) - it consists of nerve cords, evenly spaced nerve cells, or a nodal type - it is represented by a number of nodes in which the bulk of nerve cells are concentrated, connected by cords of nerve fibers (commissures and connectives). Digestive system represented by the oral cavity, pharynx, esophagus, middle and posterior intestines, liver and other glands. In the throat of mollusks there is a grater (radula), seated with many teeth. A pair of salivary gland ducts open into the pharynx. Circulatory system is not closed and usually consists of a two-chamber (due to secondary reduction of one atrium) heart and blood vessels. Respiratory system it can be represented either by gills (the so-called ctenidia), which resemble ridges in structure, or by lungs, which are a section of the mantle penetrated by blood vessels in the mantle cavity. The whole is represented by the cavity of the pericardial sac (pericardium) and the cavities of the gonads. Selection waste products are carried out by the kidney (it is also an unpaired organ). reproductive system. Among the gastropods, both hermaphrodites and dioecious animals are found. The eggs formed after fertilization (in terrestrial forms protected by dense covers - shells), from which fully developed young mollusks are then hatched, are laid by animals on various substrates. In aquatic gastropods, a larva emerges from the egg - a veliger, which later turns (metamorphosis) into an adult animal.

class cephalopods.belongs to bilaterally symmetrical molluscs. Cephalopods have clearly distinct heads. They have jaws and a grater in their mouths. Available big eyes; the sense organs are generally highly developed. The leg has developed in some way. From a simple leg, which the ancestors of cephalopods had and to which, for example, the crawling leg of worm-like mollusks is close in structure, two formations developed: a ring of limbs (arms) surrounding the mouth, and a funnel. "Hands" are primarily grasping organs, while the funnel has a dual purpose: on the one hand, it is an organ of movement, and on the other hand, it serves to communicate the mantle cavity with the external environment, in particular, to remove water used during gill breathing from the body .. Animals are always separate sexes.

9. General characteristics of the class insects.

Types of insect development. Insects are dioecious, most of them with well-defined sexual dimorphism. After leaving the egg, the development of the insect organism occurs with incomplete or complete transformation (metamorphosis). In insects with incomplete transformation, larvae hatch from eggs, similar in appearance to an adult insect, but different from it smaller sizes and underdeveloped wings and reproductive system / On the contrary, in insects with complete metamorphosis, development proceeds with a successive change of forms that are completely different from one another. A worm-like larva hatches from the egg (in a butterfly it is called a caterpillar), which crawls, eats a lot, molts several times and becomes larger with each molt. As a result of the last larval molt, a pupa is formed, which does not move and does not feed. The pupae of different orders of insects with complete metamorphosis have different structures, but what they have in common is the destruction of the anatomical structures of the larva and the use of this material to build the organs of the adult insect.

In our article we will consider the characteristics of the animal kingdom. Representatives of this systematic unit are very diverse and widely distributed in nature. These include more than 5 million species, including humans.

The Animal Kingdom: General Characteristics and Diversity

How can you tell if an organism is an animal? First of all, this is a heterotrophic way of feeding, active movement in space, a developed nervous system, a pronounced reaction to an irritant. These are the main characteristics of the Animal Kingdom.

The number of species of these representatives organic world several times higher than combined plants and fungi. Among animals, there are both microscopic unicellular organisms and real giants. For example, a humpback whale, whose body length approaches 15 meters.

Habitat

In nature, animals can be found absolutely everywhere. Their main habitat is ground-air. They run on the ground, fly, crawl in a wide variety of conditions: from hot deserts to cold tundra. A large number of animals live in water bodies. This is the dolphins. In some species, life is only partially connected with water: walruses, seals, sea ​​elephants, seals. Soil inhabitants are traditionally considered to be many types of worms. But mole rats and moles also live here. Their organs of vision are underdeveloped due to adaptation to the lack of sunlight.

Food

Consumption of prepared organic substances is the main characteristic of the animal kingdom. This feature is decisive in matters of classification. For example, the unicellular organism Chlamydomonas actively moves with the help of flagella and a light-sensitive eye. But he is the representative flora because it is capable of photosynthesis.

Active movement of the body in space is another important characteristic animal kingdoms. Unicellular species carry it out with the help of special structures. They are called organelles of movement. In ciliates, these are numerous cilia, in green euglena - a flagellum. But it does not have a permanent body shape. Its cytoplasm constantly forms temporary protrusions - pseudopodia, or pseudopodia.

Movement is carried out by more complex structures. So, coelenterates have skin-muscle cells. Contracting, they change the shape and position of the body in space. The integuments of the worms are represented by a skin-muscular sac. It consists of an integumentary epithelium, as well as one or more layers of muscles. highly organized animals musculoskeletal system. It is a combination of skeleton and muscles. The differentiation of the latter allows animals to carry out the most complex movements.

Growth

The increase in body size of most animals occurs only during a certain time of their life. Such growth is called limited. For example, the formation of a person stops at about 25 years. Unlimited growth is also a characteristic of some members of the animal kingdom. It is characteristic of crocodiles, turtles, and some species of fish.

In insects, crustaceans and reptiles, growth is accompanied by molting. The fact is that their covers are not capable of stretching. And only the shedding of the cuticle and chitin allows the body to increase in size.

Methods of reproduction and development

Most animals are characterized sexual reproduction. It occurs with the participation of germ cells - eggs and sperm. The process of their merging is called fertilization. Depending on the place in which it occurs, fertilization can be external or internal.

In the first case, germ cells merge outside the body of the female. This feature is typical for amphibians and fish. Since fertilized eggs are not protected from adverse environmental conditions, females throw thousands of eggs into the water. In the second case, both fertilization and subsequent development takes place inside the female body. Therefore, such individuals are more likely to survive, and their number is less.

In rare cases, animals can reproduce by budding. For example, freshwater hydra. First, a small protrusion forms on her body, it increases in size, acquires the features of an adult organism, after which it passes to an independent existence. Some species of crustaceans reproduce parthenogenetically. This is the development of an organism from an unfertilized egg.

Way individual development- another characteristic of the animal kingdom. These are qualitative changes in organisms. With direct development, an animal is born that is a copy of an adult organism. It is characteristic of birds, reptiles, and mammals.

If an individual is born that is significantly different from an adult, then this method of development is called indirect. For example, frog larvae look like fish fry and actively swim in the water. The same can be said about butterflies. Their larvae, which are called caterpillars, eat the leaves of plants, and the adults eat the nectar of flowers.

The best of the best

A brief description of the animal kingdom would be incomplete without an acquaintance with the most unusual of them. The record holder for size is the blue whale, reaching a length of more than 30 meters. The weight of this giant is also impressive - 190 tons. And Even a schoolboy will answer that it is a giraffe. The most surprising is the fact that with a growth of about 6 meters in his cervical region there are only 7 vertebrae. The same number for field mouse, and the chinchilla.

The title of the fastest on the planet is rightfully occupied by a cheetah, an antelope, a killer whale, and a sailboat fish. In their habitat, no one will keep up with them. Among the strong men, the rhinoceros beetle is in the lead, which is able to lift 850 times its own weight.

So, the main characteristics of representatives of the animal kingdom are:

• distribution in all habitats;
• heterotrophic nutrition;
• active movement in space;
• development of the musculoskeletal and nervous system;
• limited growth.

The animal kingdom is very diverse, it is the most numerous, with about 2 million species. Animals living on Earth are diverse in size and body shape: this is the blue whale, whose mass reaches 150 thousand tons, and the microscopic unicellular amoeba.

Despite differences in shapes and sizes, all animals have common features - cellular structure and the ability to feed, breathe, grow, develop and reproduce - like other living organisms, but animals also have special features that are not characteristic of other organisms.

The diversity of animals, their structure, features of life and behavior, reproduction, development, their origin and evolution, distribution, significance in nature and human life are studied by zoology - the science of animals.

Animals have a lot common features with representatives of other kingdoms. For example, animals and plants have a cellular structure similar to chemical composition(carbohydrates, lipids, proteins, nucleic acids, ATP, etc.), many general properties(metabolism, heredity, variability, irritability).
However, animals have special features of organization that distinguish them from plants. The most profound difference lies in the nature of the nutrition of these organisms: plants are autotrophs, and animals are heterotrophs. The vast majority of animals are mobile, they have complex behavioral reactions that are absent in plants. However, among them there are attached and inactive forms, the distribution of which is carried out by mobile larvae.

The growth of most animals has a limitation and is carried out mainly only in a certain period of their development. Only a few of them (some crayfish, crocodiles, turtles) grow throughout their lives.
Animal cells, unlike plants, do not have a cell wall, plastids, or vacuoles. The reserve carbohydrate is glycogen, and the end products of nitrogen metabolism are ammonia, urea, and uric acid.

The animal world is large and varied. To date, more than 1.5 million animal species have been described that are adapted to life on the land surface, soil, fresh and sea water, and in the air.
The importance of animals in nature is enormous. As consumers of finished organic matter, i.e. consumers, they are the most important links in food chains and networks. As a result of the processes of vital activity and mobility, animals consume, redistribute in the biosphere huge quantities matter and energy and due to this they accelerate the course of the biological cycle of substances, and the wheel of the biological cycle "spins" the faster, the smaller the size of the animal.

The role of animals (especially insects) is great as pollinators of flowering plants, seed and fruit distributors. Their contribution to soil-forming processes (worms, insect larvae, burrowing rodents) and to the formation of landscapes (burrowing animals, ungulates, beavers) is indisputable.

The significant role of animals in human life is associated primarily with the use of many species as food objects and suppliers of various forms of raw materials. Animal food enriches the human diet with high-calorie, easily digestible complete proteins. Its suppliers are different kinds crustaceans, molluscs, fish, hunting and human-bred domestic animals. Fur raw materials are supplied by many types of animals: sable, marten, squirrel, beaver, arctic fox, sea otter, cat. A person receives natural silk as a result of breeding silkworm. Suppliers of valuable medicinal raw materials are bees, snakes. The glands of some animals are used in the production hormonal drugs. Many animals are indispensable to humans as a means of transportation and physical work(horse, camel, deer, buffalo, elephant). Some representatives of the animal world are used as laboratory objects in educational and experimental work, are objects scientific research(amoeba, ciliates, beetles, insects, frogs, pigeons, rats, mice, Guinea pigs, cats, dogs, etc.).

According to modern system, the kingdom Animals are divided into two sub-kingdoms: Unicellular, or Protozoa, and Multicellular.

Giraffe. Photo: badjonni

Subkingdom of multicellular

All other animals belong to the multicellular kingdom. Recall that plants do not have a sharp line between unicellularity and multicellularity. Multicellularity repeatedly occurs independently of each other in different types of plants. In animals, however, this line is sharply expressed.

Animals differ from plants and fungi in that:

They feed on ready-made organic substances;
not capable of photosynthesis;
the vast majority are able to move and make various active movements;
there are organ systems: digestive, respiratory, nervous, excretory, musculoskeletal.
Multicellular reproduce mainly sexually, in primitive multicellular - vegetative and asexual reproduction. In some animals, parthenogenesis (same-sex, virgin reproduction) occurs.

On the basis of the absence or presence of an internal skeleton, animals are divided into two groups: invertebrates and vertebrates. The most highly organized animals are birds and mammals.

Panda. Photo: Kyle Taylor

The modern classification of animals allows you to determine the place of each species in the system of the animal world. Basic taxa for classification: type, class, order, family, genus, species.