Biology 9700 · AS & A Level · Proteins

Proteins — practice question

A change involving one nucleotide in an allele of the gene that codes for haemoglobin produces sickle cell haemoglobin. For normal haemoglobin, the mRNA base sequence for three amino acids is shown as CCUGAAGAG. For sickle cell haemoglobin, the mRNA base sequence is shown as CCUGUAGAG. The table lists some of the triplet codes for two amino acids. Which row gives the correct substituted DNA nucleotide in the allele and the substituted amino acid in the protein?

  • ADNA nucleotide A; new amino acid Glu
  • BDNA nucleotide A; new amino acid Val
  • CDNA nucleotide T; new amino acid Glu
  • DDNA nucleotide T; new amino acid Val

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