Biology 9700 · AS & A Level · Structure of nucleic acids and replication of DNA

Structure of nucleic acids and replication of DNA — practice question

The PDx1 protein is present in many different animal species, where it is considered vital for normal metabolism. In sand rats, the gene that codes for the PDx1 protein contains a much smaller proportion of A and T nucleotides than PDx1 genes from other animals. It has been difficult to determine the full DNA sequence of the PDx1 gene in sand rats. Sequencing requires removing nucleotides one at a time from single-stranded DNA. What might explain the difficulty in determining the DNA sequence of the PDx1 gene in sand rats?

  • A1, 2 and 3
  • B1 only
  • C2 only
  • D3 only

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