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

Structure of nucleic acids and replication of DNA — practice question

Which row gives the correct description of cytosine?

  • Adouble ring structure; three hydrogen bonds; purine
  • Bdouble ring structure; two hydrogen bonds; pyrimidine
  • Csingle ring structure; three hydrogen bonds; pyrimidine
  • Dsingle ring structure; two hydrogen bonds; purine

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