The accompanying pedigree shows a family in which one child (II-1) has an autosomal recessive condition. On the basis of this fact alone, provide the following information.

Using A for the dominant allele and a for the recessive allele, give the genotypes for I-1, I-2, and II-1. <>

Key Concepts

Autosomal Recessive Inheritance

Autosomal recessive inheritance occurs when a trait is expressed only when an individual has two copies of the recessive allele (aa). In this case, if a child has an autosomal recessive condition, both parents must either be carriers (Aa) or affected (aa) themselves. This means that the condition can skip generations, as carriers do not show symptoms.

Genotype Notation

Genotype notation uses letters to represent alleles, where uppercase letters denote dominant alleles and lowercase letters denote recessive alleles. For example, 'A' represents the dominant allele, while 'a' represents the recessive allele. Understanding this notation is crucial for determining the genotypes of individuals based on their phenotypes and family history.

Pedigree Analysis

Pedigree analysis is a method used to trace the inheritance of traits through generations in a family. It visually represents family relationships and the presence of specific traits, allowing for the identification of carriers and affected individuals. By analyzing the pedigree, one can infer the genotypes of family members based on the inheritance patterns observed.