Human height is a trait with a very broad range of phenotypes. Which pattern of inheritance could account for human height? Explain your answer.
Becuase there is a broad range of phenotypes for human height, the trait is an example of a polygenetic (poly = many, genetic = of genes) trait.
Due to the vast variations of human height, the trait is clearly not purely dominant or recessive. A dominant trait is due to a dominant allele (variation of a gene) which completely masks a recessive allele. If only dominant and recessive height phenotypes existed, there would only be two heights observed in humans!
Since there is such a vast variation amongst human heights, the trait is an example of a polygenetic trait. Polygenetic traits are traits that are influenced by more than one gene at multiple loci (locations) on one or more chromosomes. This results in a continuous distribution of traits within a species. Other examples of polygenetic traits include skin color, hair color, and weight.