Question

Study of pedigree chart. What does it show?

• A. Inheritance of a condition like phenylketonuria as an autosomal recessive trait
• B. Inheritance of a recessive sex-linked disease like haemophilia
• C. Inheritance of sex-linked inborn error of metabolism like phenylketonuria
• D. Pedigree chart is wrong as this is not possible

Answer 1

The correct option is A Inheritance of a condition like phenylketonuria as an autosomal recessive trait

The above-given pedigree chart shows an autosomal recessive disorder. In this pedigree chart, the trait is not expressed by both parents. If the parents are carriers of abnormal genes, then their offspring can express the trait. Therefore, the above pedigree chart shows the inheritance of a condition like phenylketonuria as an autosomal recessive trait.
So, option (a) is the correct answer.