What symbol represents a diseased or affected female in a pedigree chart?

In pedigree charts, symbols are used to represent individuals and their health status, particularly in the context of inherited diseases or conditions. A filled-in circle specifically represents a female who is affected by a particular genetic condition or disease. This visual cue helps quickly identify not only the sex of the individual but also their health status, which is crucial when analyzing patterns of inheritance within families.

In contrast, an empty circle denotes a female who is unaffected, and an empty square signifies an unaffected male. A filled-in square would indicate an affected male. Therefore, recognizing the filled-in circle as the symbol for a diseased or affected female is essential when interpreting pedigree charts accurately.