The first truly scientific step in the study of heredity was taken by the Austrian monk Gregor Mendel (1822-1884), who in 1865 published an article substantiating the basic laws of heredity. Mendel showed that hereditary tasks do not mix, but are passed from parents to descendants in the form of discrete, that is, isolated, units, or particles. These units, which are represented in pairs in individuals, are passed on to subsequent generations in male and female gametes, each of which contains one unit from each pair. To evaluate this conclusion, it is necessary to take into account that in the spirit of that time, heredity was considered continuous rather than discrete, as a result of which, as it was believed, ancestral traits were “averaged” in descendants. Mendel’s ideas were ahead of the era and were not accepted by his contemporaries. The official year of the “birth” of genetics is considered to be 1900, the year of the rediscovery of Mendel’s laws by G. de Vries, K. Correns and E. Cermak. In 1909, the Danish botanist Johansen named the discrete units discovered by Mendel as genes, and in 1923, the American geneticist Morgan showed that they are located on chromosomes. A new era of modern genetics, and indeed of all biology, begins in 1953, when J. Watson and F. Crick have published a structural model of DNA. But even now, despite the outstanding discoveries and achievements, genetics is full of mysteries. This makes her intriguingly interesting. The contradictions of the provisions of classical Darwinism to the newly discovered laws of genetics served as the basis for the emergence of a new synthetic theory of evolution, which even now most biologists do not doubt. Since then, genetics has made great strides in explaining the nature of heredity at both the body and gene levels. This is a promising science, the development of which does not stop. A working draft of the human genome structure was released in 2000, and the complete genome was sequenced in 2003. However, additional analysis of some sections has not yet been completed. Modern genetics is an extensive tree of derived disciplines. Its specialized sections began to be considered as large independent sciences — human genetics, cytogenetics, molecular genetics, population genetics, immunogenetics, environmental genetics, developmental genetics, genomics, and others. Genetics as a science solves many problems in various fields. She studies substances and structures that form the material foundations of heredity, ensure continuity between generations, determine the similarity of individual development; mechanisms for the realization of hereditary information in the process of individual development of organisms; issues of environmental influence on the formation of traits in the process of individual development of organisms; variability as a universal property of organisms, forms and causes of this phenomenon. Genetics is increasingly becoming part of people’s daily lives, largely determining the future of humanity. It is expected that detailed knowledge of the human genome will open new paths to success in medicine and biotechnology.