Final answer:
The genotypes of individuals labeled 1, 2, and 3 on the pedigree chart for autosomal recessive inheritance are aa, AA, and AA respectively. Unaffected individuals could be heterozygous carriers (Aa), but affected individuals must be homozygous recessive (aa).
Step-by-step explanation:
The question relates to the interpretation of a pedigree chart for autosomal recessive inheritance. Considering the recessive nature of the trait, affected individuals will have a genotype of aa (homozygous recessive), while unaffected individuals may be either AA (homozygous dominant) or Aa (heterozygous carriers). From the information provided, individuals 1, 2, and 3 must have the following genotypes: individual 1 would be aa, individual 2 would be AA, and individual 3 would be AA, as they are all unaffected. It is important to remember that individuals with an unaffected phenotype can still carry one copy of the recessive allele, which would not be expressed phenotypically. Hence, if individuals 1 and 2 had a child that is affected (aa), they could have genotypes of Aa (heterozygous carriers) if they are not suffering from the disorder themselves.