Genetics is a discipline of biology.[1] It is the science of heredity. This includes the study of genes, and the inheritance of variation and traits of living organisms.[2][3][4] In the laboratory, genetics works by mating carefully selected organisms, and analysing their offspring. More informally, genetics is the study of how parents pass some of their characteristics to their children. It is an important part of biology, and gives the basic rules on which evolution acts.
The fact that living things inherit traits from their parents has been known since prehistoric times. It is used to improve crop plants and animals by selective breeding. The modern science of genetics tries to understand the process of inheritance. This began with the work of Gregor Mendel in the mid-nineteenth century.[5][6] Although he did not know the physical basis for heredity, Mendel saw that organisms inherit traits via discrete units of inheritance, now called genes.
Modern genetics has expanded beyond inheritance. It studies the way genes work.