Biology 9700 · AS & A Level · Cells as the basic units of living organisms

Cells as the basic units of living organisms — practice question

The diagram shows part of a DNA molecule. Two of the bases in this section are marked 1 and 2. Which row correctly names bases 1 and 2?

  • Abase 1: purine; base 2: adenine
  • Bbase 1: purine; base 2: guanine
  • Cbase 1: pyrimidine; base 2: adenine
  • Dbase 1: pyrimidine; base 2: guanine

Worked solution & mark scheme

This 1-mark question has a full step-by-step worked solution and mark scheme.

  • Full mark scheme, point by point
  • Step-by-step worked solution
  • Write your answer & get it marked instantly by AI