Zoology - Principles of Inheritance and Variation Question with Solution | TestHub

The given pedigree shows the inheritance of a condition such as phenylketonuria as an autosomal recessive trait. Since the parents are normal and children are affected, the disease is in recessive form. In first-generation, both males and females are equally affected. Since the disease is recessive, for a girl to be affected by an unaffected father, the disease has to be autosomal recessive.