Question

In a pedigree of a family given below, the trait denoted by A is inherited as dominant, autosomal trait. What will be the genotype of mother and father?
Note: AA- Homozygous dominant, aa- Homozygous recessive, Aa- Heterozygous dominant

• A. Mother is aa and father is Aa
• B. Father is AA and mother is aa
• C. Father is Aa and mother is Aa
• D. None of the above

Answer 1

The correct option is A Mother is aa and father is Aa

It is given that the trait in pedigree is autosomal dominant. In the pedigree, mother is normal so its genotype is aa. Father is affected, so its genotype can be Aa or AA. But one of their sons and daughters each are normal i.e., their genotype is aa. Thus, father must be Aa. Hence, mother is aa and father is Aa.