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NEET2019ZoologyPrinciples of Inheritance and VariationActual

Assertion : Phenylketonuria, haemophilia and sickle cell anaemia are genetic disorders. Reason : In phenylketonuria, the person lacks an enzyme for the conversion of phenylalanine into tyrosine.

Options

  1. AIf both assertion and reason are true and reason is the correct explanation of assertion.
  2. BIf both assertion and reason are true but reason is not the correct explanation of assertion.
  3. CIf assertion is true but reason is false.
  4. DIf both assertion and reason are false.

Correct answer

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

Step-by-step solution

Phenylketonuria is inborn error of metabolism inherited as the autosomal recessive trait. The affected individual lacks an enzyme that converts the amino acid phenylalanine into tyrosine. As a result of this phenylalanine is accumulated and converted into phenylpyruvic acid and other derivatives. Accumulation of these in brain results in mental retardation. These are also excreted through urine because of its poor absorption by kidney.

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