Fully penetrant single-gene traits are characteristics that are determined by the presence or absence of a specific gene. These traits are often inherited and are expressed in either a dominant or recessive fashion. Some synonyms for fully penetrant single-gene traits include Mendelian traits, monogenic traits, and deterministic traits. These traits have a clear pattern of inheritance and are present in all individuals who inherit the gene. They can manifest in a variety of ways, from physical characteristics to diseases and disorders. Understanding the inheritance and expression of these traits can provide valuable insight into human genetics and contribute to improved medical treatments and interventions.