Biology 5090 · O Level · Inheritance

Inheritance — practice question

Phenylalanine is one of many different amino acids. The diagram presents the structure of a phenylalanine molecule.
(a(i))[1]

Name the human organ that carries out metabolism of amino acids such as phenylalanine.

(a(ii))[3]

Explain how the shape of a PAH enzyme molecule helps phenylalanine to be metabolised.

(b(i))[2]

Describe what is meant by the term gene mutation.

(b(ii))[3]

Explain how a person with the condition should adjust their diet to lower the chance of brain damage.

(b(iii))[3]

Complete the genetic diagram to show the chance that two carriers will have offspring with the condition.

Worked solution & mark scheme

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