Question

Assertion: A patient with phenylketonuria has skin pigmentation, mental retardation, and reduction in hair

Reason: In phenylketonuria, phenylalanine is converted into tyrosine which leads to absence of phenylalanine in the body

• A. Both assertion and the reason are true and the reason is a correct explanation of the assertion
• B. Both the assertion and reason are true but the reason is not the correct explanation of the assertion
• C. Assertion is true but the reason is false
• D. Both the assertion and reason are false

Answer 1

The correct option is C Assertion is true but the reason is false

Phenylketonuria is an autosomal recessive disorder. The homozygous recessive individuals lack an enzyme called phenylalanine hydroxylase which converts phenylalanine to tyrosine in the liver. The absence of this enzyme leads to the accumulation of phenylalanine in the body causing skin pigmentation, mental retardation, and loss of hair. So, the assertion is true but the reason is false.