Why does a dominant trait appear in every generation of a pedigree?

A dominant trait appears in every generation of a pedigree because it is expressed when at least one copy of the dominant allele is present. This means that even if an individual carries only one dominant allele (heterozygous), the trait will be observable. As a result, dominant traits can be passed from affected parents to their offspring, making them visible in each generation. In contrast, recessive traits require two copies of the recessive allele to be expressed, so they may skip generations.