Concept: Compare Genetic Variations in Plants and Animals TEK B.6D Concept: Compare Genetic Variations in Plants and Animals

Astigmatism is an autosomal dominant trait Astigmatism is an autosomal dominant trait. In analyzing a pedigree the offspring showing the affected trait must then have at least one parent that is affected. In the first generation individual 5 is not affected by astigmatism; therefore, individual 1 must be heterozygous for astigmatism. Individual 2 has normal vision, which is a recessive trait, and therefore has a genotype of aa.