Question

Be able to explain how environment influences traits by interacting with genes using the example of phenyl-ketonuria caused due to phenyl alaninehydroxylase deficiency.

Answer 1

Phenylketonuria (PKU) is a genetic disorder caused by a deficiency in the enzyme phenylalanine hydroxylase. The environment, specifically diet, can influence the expression of this disorder. Individuals with PKU need to follow a strict low-phenylalanine diet to avoid symptoms and damage.

Step-by-step explanation:

Phenylketonuria (PKU) is a genetic disorder caused by a deficiency in the enzyme phenylalanine hydroxylase, which is responsible for converting phenylalanine into tyrosine. The environment can influence the expression of this genetic disorder. For example, individuals with PKU need to closely follow a strict diet that is low in phenylalanine to avoid symptoms and damage. Phenylalanine is found in high concentrations in certain foods, and intake of these foods should be carefully monitored.

PKU is typically detected in newborns through screening tests, and early diagnosis and intervention can help mitigate the severity of symptoms. Pregnant women with PKU need to pay special attention to their diet to prevent excessive phenylalanine exposure to their fetus, which can lead to developmental problems. This example illustrates how the interaction between genes and the environment, specifically diet, can influence the expression of a genetic disorder.