Biology 9700 · AS & A Level · Carbohydrates and lipids

Carbohydrates and lipids — practice question

XNA is a nucleic acid produced in the laboratory from nucleotides, with one constituent substituted by chemical X. Chemical X does not occur naturally. The coding section of the molecule remains unchanged. Which organic component of a DNA or RNA nucleotide has been substituted by X?

  • Afive-carbon sugar
  • Bphosphate group
  • Cpurine base
  • Dpyrimidine base

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