Which inheritance pattern describes a dominant allele on an autosome?

The inheritance pattern that describes a dominant allele on an autosome is autosomal dominant. In this type of inheritance, a single copy of the dominant allele, present on one of the non-sex chromosomes (autosomes), is sufficient to express the trait or condition associated with that allele. This means that an individual only needs one copy of the dominant allele from either parent to demonstrate the trait in their phenotype.

In autosomal dominant conditions, affected individuals typically have at least one affected parent. The trait can appear in every generation, and both males and females are equally likely to inherit and express the phenotype. Examples of autosomal dominant conditions include Huntington's disease and Marfan syndrome.

Understanding this inheritance pattern is crucial as it helps in predicting the likelihood of passing certain traits or disorders to offspring based on family history and the genetic makeup of parents.