The accompanying figure shows the pedigree for a family. Dark-shaded symbols represent individuals with one of the two major types of colon cancer. Numbers under the symbols are the individual's age at the time of diagnosis. Males are represented by squares, females by circles. From this pedigree, this trait seems to be inherited ________.

Question

The accompanying figure shows the pedigree for a family. Dark-shaded symbols represent individuals with one of the two major types of colon cancer. Numbers under the symbols are the individual's age at the time of diagnosis. Males are represented by squares, females by circles.  From this pedigree, this trait seems to be inherited ________.

Quizplus · Accepted Answer

The trait appears to be inherited as an autosomal dominant, as it is present in every generation and affects both males and females. Autosomal recessive traits would only be present in individuals who inherit two copies of the gene (one from each parent) and would not affect every generation. Epistasis and incomplete dominance both involve interactions between separate genes, which are not apparent in this pedigree. Maternal inheritance would result in the trait being passed only from the mother to her offspring, which is also not apparent in this pedigree.

The Accompanying Figure Shows the Pedigree for a Family