What does a pedigree chart illustrate?

A pedigree chart is a graphical representation that illustrates the inheritance patterns of specific traits across generations within a family. It visually tracks the transmission of genetic characteristics, allowing for analysis of how traits are passed from one generation to the next, which helps in identifying dominant and recessive traits. By examining who has a particular trait within the family tree, one can make determinations about potential genetic disorders or inheritance patterns.

In contrast, the other options focus on different aspects of genetics and biology. The genetic composition of an organism deals with its entire genetic makeup, rather than the specific inheritance of traits within a lineage. The effects of mutations over generations may be observable, but a pedigree chart does not specifically track these mutations. Lastly, the relationship between environmental factors and traits pertains to how outside conditions influence genetic expression, which is outside the scope of what a pedigree chart primarily demonstrates. Therefore, a pedigree chart is distinctively suitable for illustrating the inheritance of specific traits through familial lines.