The term for the study of heredity and the variation of inherited characteristics is called genetics. It investigates how traits are passed from parents to offspring through genes, which are segments of DNA. Genetics encompasses various subfields, including Mendelian genetics, which focuses on inheritance patterns, and population genetics, which examines genetic variation within populations. Understanding genetics is fundamental in fields such as medicine, agriculture, and evolutionary biology, providing insights into traits, diseases, and the mechanisms of evolution.