EduNinja
Learning objective

A1.2.3—Sugar-phosphate bonding

Nucleotides join by condensation reactions to form a continuous sugar-phosphate backbone, leaving bases exposed to carry sequence information along each strand.

Syllabus
First assessment 2025
Objective
A1.2.3
Level
SL

Concept essentials

  • Sugar-phosphate bonding should be described using precise molecular vocabulary.
  • Structure and information must be kept separate: backbones provide continuity while bases carry sequence meaning.
  • Exam answers should match the command term and avoid adding unsupported extra claims.

Exam analysis

Question evidence linked specifically to this learning objective.

Chance of appearing6%of analysed past papers
Latest appearanceMay 2023
Most common paperPaper1
Typical marks1

Common command terms

  • Identify
  • Outline

Exam question appearances

May 2023Paper1 SL · TZ210[ 1 ]A1.2.3—Sugar-phosphate bonding
November 2021Paper1 SL · TZ010[ 1 ]A1.2.3—Sugar-phosphate bonding
May 2021Paper1 SL · TZ29[ 1 ]A1.2.3—Sugar-phosphate bonding
May 2018Paper1 SL · TZ111[ 1 ]A1.2.3—Sugar-phosphate bonding
November 2015Paper1 SL · TZ08[ 1 ]A1.2.3—Sugar-phosphate bonding

Coverage 2010–2023 · Updated 14 Jul 2026

Focused stepA1.2.3—Sugar-phosphate bonding