What is the term for a diagram showing the occurrence of a genetic trait over several generations?

The term for a diagram that illustrates the occurrence and inheritance of genetic traits across multiple generations is known as a pedigree. A pedigree chart specifically documents how a particular trait or genetic condition is passed down through family members. It provides a visual representation of relationships among family members and highlights the inheritance patterns of specific traits, which can be crucial for understanding genetic disorders.

Pedigrees are utilized in genetics to trace traits through succeeding generations, allowing for assessments of the likelihood that specific traits will be present in future offspring. The use of standardized symbols and notation in a pedigree makes it clear who is affected by various genetic traits, enabling easier interpretation of genetic information.

While a family tree also traces lineage and relationships, it typically focuses on the family structure rather than the presence of specific genetic traits. A genogram may include some health information, but it is primarily used in social work and psychology to map out familial relationships and behaviors. A progeny chart, on the other hand, is less commonly used in genetics and does not specifically convey inheritance across generations in the same detailed manner that a pedigree does.