Among the variety of organisms, animals occupy their niche. Representatives of this kingdom are very numerous and diverse. Euglena green, freshwater hydra, dragonfly, beauty, lake frog, duck mallard, polar bear ... What are the signs that they are united in one kingdom? What are the general properties of an animal organism? The answers to these questions are in our article.
The main properties of the animal organism
Animals have mastered all habitats. They can live on earth and in soil, in air, in water, and parasitic species - in other organisms. Common to them are the cellular structure, the unity of the chemical composition, type of nutrition, growth characteristics, metabolic processes, and the ability to move. The differences between these signs are due to different conditions: the temperature of water or air, the presence of solar energy, the quantity and nature of food.
Power way
The properties of the animal organism are primarily determined by the method of nutrition. On this basis, they are heterotrophs. This means that animals are able to consume only ready-made substances. They get food in different ways. For example, predators attack their prey, and saprotrophs decompose dead organics. Parasitic animals feed on other organisms. The nature of the food depends on the structural features of various organs. For example, fangs are well developed in predators, but in rodents they are absent and replaced with additional incisors.
Cell Level Features
Animal cells are also characterized by a number of signs. First of all, this is the absence of green chloroplast plastids, which determines their inability to photosynthesis. The cell wall consists of compounds of carbohydrates with proteins and lipids and is represented by glycocalyx. Such a chemical composition determines the elasticity and strength of this structure. Many properties of the animal organism are also due to the presence of a nucleus in their cytoplasm. This organelle contains genetic material and is involved in the division process. Unicellular animals, for example, euglena, ciliates, amoeba, breed by crushing in two. Their vacuoles do not contain spare substances. These structures perform the functions of digesting food particles and removing excess salts and water.
Motion
The properties of an animal organism are also determined by their ability to actively move in space. This important ability is provided by specialized structures. The simplest animals have organelles of movement. They can be represented by cilia, flagella or pseudopods. In multicellular animals, the musculoskeletal system performs this function. It consists of a skeleton, muscles and ligaments. The limbs of animals can be modified. The nature of metamorphosis depends primarily on the characteristics of the habitat of organisms. So, in birds, the upper limbs are turned into wings, and in aquatic mammals - into flippers. In any case, all animals actively move in space in search of food and better living conditions.
Height
Animal growth is limited. This means that quantitative changes occur only until a certain period of life, after which they cease. For example, cats and dogs grow up to about 3 years, and humans - up to 20. Quantitative changes are always accompanied by qualitative changes - development. This is manifested in the complication of various physiological processes.
So, the characteristic properties of an animal organism are a heterotrophic method of nutrition, the ability to actively move, and limited growth. It is on these grounds that the classification and systematic position of these creatures is determined.