Final answer:
The question is about determining the genotypes of individuals listed to the left in a pedigree chart, which falls under high school Biology. Individual 1 is homozygous recessive (aa) and exhibits a genetic disorder, while individuals 2 and 3 are homozygous dominant (AA) and do not exhibit the disorder.
Step-by-step explanation:
The subject matter of this question falls within the field of Biology, specifically focusing on genetics and the determination of genotypes. We're asked to determine the genotypes of individuals listed to the left in a pedigree chart, which is a diagram representing the genetic relationships within a family. This type of question is typically encountered in a high school biology curriculum.
In reference to the given information, individual 1 is labelled with genotype aa, indicating that they are homozygous recessive. This means they express a genetic disorder that is represented in blue in the pedigree. Individuals 2 and 3 are labelled as AA, suggesting they are homozygous dominant and do not exhibit the genetic disorder.
Based on the provided context, we know that an individual could be determined homozygous dominant, heterozygous, or homozygous recessive using phenotype observations and additional pedigree information. If they exhibit the recessive trait, like the person labelled 1, they must be aa. If they do not, like individuals 2 and 3, they could be AA or Aa without further context—but here, they are identified as AA.