The systematic category of animals: basic taxa and classification principles

The subject of systematic science is the classification of living organisms. The association of beings into groups on the basis of certain characteristics is of great practical importance for their study. The main systematic categories of animals and the principles laid down in their classification will be considered in our article.

Basics of animal classification

On what grounds can animals be distinguished from the whole variety of living organisms? On a single - method of nutrition. All animals, from a microscopic amoeba to a giant whale, are heterotrophs. This means that they eat only ready organic substances and are not able to produce them on their own.

The lowest taxa of animals is a species. This group of individuals, which are united by the principle of similarity of structure, physiology and ecology. This systematic category of animals has a double name. It was first introduced into science by the famous scientist Carl Linnaeus. May beetle, migratory locust, polar owl - the first name is species. The second word determines the genus to which the animal belongs.

Systematic categories of animals: table

The systematic units are also called taxa. The species and genus are the smallest of them. The largest taxon is a kingdom. At the present stage, taxonomists distinguish five of them. These are plants, fungi, bacteria, viruses and animals. Their main difference is the way of feeding and the peculiarities of the structure of the cell. The sequence of systematic categories of animals is given in our table.

Unicellular

The systematic category of animals, which are the simplest, unites unicellular organisms. All of them are eukaryotes. Their cell is a holistic organism capable of carrying out all vital processes: nutrition, breathing, growth, reproduction, movement.

Typical examples of animals that are related to the unicellular sub-kingdoms are amoeba proteus, euglena green, and infusoria shoe.

Multicellular

The body of representatives of this systematic unit is not simply formed by a multitude of cells. These are the smallest structures, similar in structure and function, which are consistently combined into tissues, organs and their systems. This systematic category of animals includes several types, the structure of which is consistently more complicated. There are seven in total. The most primitive in structure are the sponges. These organisms lead an attached lifestyle, eating by filtration. Freshwater hydra, jellyfish and polyps are representatives of the type of the intestinal. They have specialized cells that do not yet form real tissues.

For the first time these structures appear in worms, which form several types of animals: flat, round and ringed. And the latter are characterized by the appearance of the circulatory system. The next type of multicellular animal is called mollusks. They have a soft body that is not segmented and often protected by a shell. The largest in species diversity is the type of arthropod, which combines insects, rako- and arachnids.

Chord

This systematic category of animals is the most complex and has a general outline of the structure. This is the presence of axial strand, or chord, neural tube and gill slits in the pharynx. Depending on the habitat, they are modified. Representatives of the chord classes are known to everyone and are widely used by man in economic activities. These include typical aquatic inhabitants - fish, which are characterized by gill respiration. Amphibians live on land, and reproduce in water bodies. These are frogs, toads and frogs. The reptiles - crocodiles, lizards, snakes, turtles - come out completely on land. And the birds resigned air habitat. The most highly organized animals of the chordate type are mammals, of which man is a representative.

So, to the animal kingdom are living organisms, for which a heterotrophic type of food is characteristic. Representatives of this systematic unit are united in the following taxa:

• Sub-kingdom of unicellular;
• Subcellation of multicellular.

The latter include: sponges, coelenterates, flat, round and annular worms, mollusks, arthropods, mammals.