Bacteria (Gr. Bacterion - Rod)
Bacteria are very small, usually unicellular microorganisms, which are characterized by the absence of a formed nucleus.
Bacteria are widespread in nature. They live in soil, water, air, as well as in the organisms of plants, animals and humans. The size of bacteria is very small - their length is usually 1-5 microns.
Bacteria lack a nucleus, typical of eukaryotic cells. Instead, the genetic material of bacteria is contained in the nucleoid, a separate region of the cytoplasm.
Bacteria reproduce by dividing the cell in two. This process can occur very quickly under favorable conditions, so the bacterial population is able to rapidly increase in number.
Bacteria play an important role in nature and human life. They participate in the cycle of substances and are used in the food and pharmaceutical industries. However, some types of bacteria are causative agents of dangerous infectious diseases.