Amoeba is a typical unicellular animal

Amoeba is a representative of single-celled animals, capable of actively moving by means of special specialized organelles. The features of the structure and the significance of these organisms in nature will be revealed in our article.

Characteristics of the sub-kingdom Protozoa

Despite the fact that the protozoa have such a name, their structure is quite complex. After all, one microscopic cell, capable of performing the functions of the whole organism. Amoeba is another proof of this. This organism, up to 0.5 mm in size, is able to breathe, move, multiply, grow and develop.

Movement of protozoa

Unicellular organisms are moved by means of special organelles. In infusorians, they are called cilia. Just imagine: on the surface of the cell, up to 0.3 mm in size, there are about 15,000 of these organelles. Each of them makes pendulum movements.

Euglena has a flagella. Unlike the cilia, it makes helical movements. But these organelles are united by the fact that they are constant outgrowths of the cell.

The movement of the amoeba is due to the presence of pseudopods. They are also called pseudopodia. These are unstable cellular structures. Due to the elasticity of the membrane, they can be formed anywhere. First, the cytoplasm moves outward, and protrusion is formed. Then the reverse process follows, the pseudopods are directed into the cell. As a result, the amoeba moves slowly. The presence of pseudopods is a distinctive feature of this representative of the Unicellular sub-kingdom.

Ameba Protey

Amoeba is an organism that got its name from the name of one of the characters of Greek myths, Proteus, because he was able to change his appearance. This is a colorless single-celled animal that can be found in fresh water bodies, soil, human and animal organisms. It is a heterotrophic organism, which is powered by unicellular algae and bacteria.

The structure of amoeba

All cells of the protozoa are eukaryotic - they contain a nucleus. The organs of amoeba, or rather its organelles, are capable of carrying out all processes of vital activity. Spoon-legs participate not only in the movement, but also provides the process of feeding amoeba. With their help a single-celled animal covers a particle of food that is surrounded by a membrane and is inside the cell. This is the process of formation of digestive vacuoles, in which the splitting of substances takes place. Such a method of absorption of solid particles is called phagocytosis. Undigested food remains isolated anywhere in the cell through the membrane.

Amoeba, like all protozoa, does not have specialized organelles of respiration, carrying out gas exchange through the membrane.

But the process of regulation of intracellular pressure is carried out with the help of contractile vacuoles. The content of salts in the environment is higher than inside the body itself. Therefore, according to the laws of physics, water will flow into the amoeba - from an area with a higher concentration to a smaller one. The contractile vacuoles regulate this process, producing together with water some metabolic products.

For amoebae, asexual reproduction is inherent in dividing the cells in two. This is the most primitive of all known methods, but it ensures the exact preservation and transfer of hereditary information. First, the fission of the nucleus, organelles, and then the isolation of the cell membrane occurs.

This simplest organism is able to react to the action of environmental factors: light, temperature, change in the chemical composition of the reservoir.

Unfavorable conditions are transferred unicellularly in the form of cysts. Such a cell stops movement, water content decreases in it, and pseudopods are drawn in. And she herself is covered with a very dense shell. This is the cyst. When favorable conditions come, the amoeba go out from the cysts and go on to the usual processes of life.

Dysenteric amoeba

Amoeba is not only an innocuous inhabitant of fresh water bodies, which is a part of plankton. One of its species, called dysentery amoeba, lives in the lumen of the human intestine. Here, the unicellular organism leads a parasitic life, feeding on bacteria. Penetrating into the intestinal wall, the amoeba destroys the cells of the mucous membrane and red blood cells - red blood cells. As a result, ulcers appear on the surface. Together with undigested food remnants parasitic animals come out. Infecting with dysentery can be with the use of raw water, unwashed vegetables and fruits, not observing the rules of personal hygiene.

Many species of these protozoa play a positive role in nature. Amoeba are a source of nutrition for many animals, namely fish fry, worms, mollusks, small crustaceans. They clean freshwater from bacteria and rotting algae, are an indicator of the purity of the environment. Shell amoebae took part in the formation of limestone and Cretaceous sediments.