What does a pedigree chart illustrate?

A pedigree chart is a visual representation used to study the inheritance of traits within a family across multiple generations. It provides a comprehensive overview of how certain genetic traits or conditions are passed down, highlighting which family members exhibit those traits and which do not. This clarity allows for the identification of patterns of inheritance, such as dominant or recessive traits, making it easier to trace how a specific characteristic might be inherited.

In contrast, genetic mapping of chromosomes involves pinpointing the specific locations of genes on chromosomes, which is a more technical analysis than what a pedigree chart provides. The types of genetic mutations refer to alterations in DNA sequences that may or may not be visually represented in a pedigree. Similarly, chromosome aberrations pertain to structural changes in chromosomes, which again is a different focus than the trait inheritance highlighted in pedigree charts. Thus, the essence of a pedigree lies in its ability to demonstrate the presence or absence of traits across generations, making option B the appropriate answer.