1. The pedigree shows an autosomal recessive inheritance pattern.
2. Individuals I-1 and I-2 are both carriers (heterozygous) for the trait.
3. Individual II-3 is affected, meaning they inherited two copies of the recessive allele.
4. Individual II-4 is unaffected but could be either homozygous dominant or a carrier.
5. The probability that individual III-1 is a carrier is 2/3.
6. The probability that individual III-2 is a carrier is 1/2.
7. The probability that their child (IV-1) will be affected is 1/12.
8. The probability that their child (IV-1) will be a carrier is 5/12.
9. The probability that their child (IV-1) will be unaffected and not a carrier is 1/2.
10. The trait is not sex-linked because it affects males and females equally and does not skip generations in a pattern typical of X-linked traits.
Parent Tip: Review the logic above to help your child master the concept of genetic pedigree worksheet.
