EN
A broad analysis of organisms is possible using molecular DNA as a marker. Mitochondrial genome and genes present in mtDNA, e.g. cytochrome b gene, are widely used in investigations and the significance of this research is becoming increasing. This gene is coded by heavy (H) strand of mtDNA. Cytochrome b is one of 11 subunits composed of bc1 complex of respiratory chain of mitochondria, the sequence of which is written down in the mitochondrial genome. Cytochrome b gene traits are a slow rate of variations during evolution, the presence of some parts of the gene that are more conserved and those which show high divergence rates. Those traits make the cytochrome b gene useful as a marker in many analyses. The cytochrome b gene is used as a tool in such studies as: legal and veterinary medicine, palaeontology, as well as phylogenetics, and it can attain the status of a universal metric.