Question

Given below is a pedigree showing the inheritance of an autosomal dominant disorder.

The genotypes of person 1, 2 and 3 in this family tree are:

• A. 1=MM ,2 =Mm ,3=mm
• B. 1=MM , 2=MM ,3=mm
• C. 1=Mm , 2= MM , 3=Mm
• D. 1=Mm ,2=Mm ,3 = mm

Answer 1

Answer: (D)

In the above pedigree, person 1 has Mm genotype (M id dominant over m), person 2 has Mm genotype (M is dominant over m) and because of the presence of a dominant gene, they both are disease sufferer. But person C (genotype mm) is normal because there is no dominant gene in her genotype.