The best example of pleiotrpy isASkin colourBPhenylketonuriyaCColour blindnessDABO Blood groupAnswer: B. Phenylketonuriya Read Explanation: Phenylketonuria is an example of pleiotropy. It is a metabolic disorder, which occurs due to a defective gene for the enzyme phenylalanine hydroxylase. It causes multiple phenotypic expressions. Read more in App