Question
Biology Question on Principles of Inheritance and Variation
Given below are two statements :
Statement I: Phenylketonuria is an example of Pleiotropy
Statement II: Affected individuals lack an enzyme which converts pheylalanine into tyrosine
In the light of the above statements, choose the most appropriate answer from the options given below :
Both Statement I and Statement II are correct
Both Statement I and Statement II are incorrect
Statement I is correct but Statement II is incorrect
Statement I is incorrect but Statement II is correct
Both Statement I and Statement II are correct
Solution
Both Statement I and Statement II are correct.
Statement I: Phenylketonuria (PKU) is an example of Pleiotropy. Pleiotropy refers to a single gene influencing multiple phenotypic traits. In the case of PKU, a mutation in the gene responsible for producing the enzyme phenylalanine hydroxylase (PAH) leads to various phenotypic effects beyond the inability to metabolize phenylalanine.
Statement II: Affected individuals lack an enzyme that converts phenylalanine into tyrosine. This statement accurately describes the underlying cause of PKU. Due to the absence or dysfunction of phenylalanine hydroxylase, individuals with PKU cannot convert phenylalanine into tyrosine, leading to an accumulation of phenylalanine in the body.
Therefore, both Statement I and Statement II are correct.