Question

Assertion: Phenylketonuria is a recessive hereditary disease caused by body's failure to oxidise an amino acid phenylalanine to tryrosine, because of a defective enzyme.
Reason: It results the presence of phenylalanine acid in urine.

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

Answer 1

Answer: (B)

If both the assertion and reason are true but the reason is not a correct explanation of the assertion

Phenylketonuria is due to deficency of liver enzyme Phenyanaline hydroxylase which converts phenylanine into tryosine. It occurs in person who are homozygous recessive. It results with a high level of phenylalanine in blood, tissue fluids and urine. Therefore both assertion and reason is true.

So, the correct answer is 'If both the assertion and reason are true but the reason is not a correct explanation of the assertion'