Which diagram shows the occurrence and appearance of a trait across generations and can be used to track inheritance?

• A. Chromosome
• B. Chromatids
• C. Pedigree chart
• D. Chromatin

Answer: (C)

Pedigree charts are used to track how a trait appears across generations in a family. They lay out individuals in generations, with symbols for gender and shading to show who expresses the trait, so you can see how the trait is passed down. This format lets you infer inheritance patterns—whether a trait is autosomal or sex-linked, and whether it’s dominant or recessive—by looking at patterns like whether affected individuals appear in every generation or skip generations, and whether affected parents produce affected offspring. Other terms like chromosome, chromatids, and chromatin are cellular components and don’t illustrate trait transmission across generations, so they don’t serve this purpose.