Question

The pedigree below shows the inheritance pattern of a sex-linked allele for one family. What is true about the genotype of individuall-2? 1-1 1-2 II-1 II-2 II-3 II-4 III-1 III-2 The disease is caused by a dominant allele (D) and his genotype is dd He must have the genotype X'Y The disease is caused by having two recessive alleles (dd) and his genotype is He has the recessive disease allele on his X chromosome XY He has the dominant disease allele on his X chromosome (XⓇY)

Answer 1

Ans- He has the recessive disease allele on his x- chromosome ( XdY)

When completing this pedigree with X-linked dominant inheritance, use the symbols X and Y in the genotype to represent the sex chromosomes passed on from the previous generation. The X chromosome will contain the alleles for the trait and the Y chromosome will have no alleles for this trait. When completing this pedigree with X-linked dominant inheritance, non-shaded females who are expressing the recessive phenotype and can only have the genotype of XrXr, the non-shaded males who are expressing the recessive phenotype and can only have the genotype of Xry, and the shaded males who are expressing the dominant phenotype and can only have the genotype XRY. Use this knowledge and additional knowledge about how genes are passed from generation to generation to complete the remainder of the pedigree.