IB Biology SL 1.2.6 DNA Double Helix Question Bank
Practise IB Biology SL 1.2.6 by interpreting DNA diagrams, complementary base pairs and the covalent and hydrogen bonds of the double helix.
- Syllabus
- First assessment 2025
- Course
- Biology SL
- Level
- SL
Practise IB Biology SL 1.2.6 by interpreting DNA diagrams, complementary base pairs and the covalent and hydrogen bonds of the double helix.
Draw a labelled diagram to show how four nucleotides are joined together to form a double-stranded DNA molecule with two base pairs.

Two sugar-phosphate strands shown connected through bases.
A sugar-phosphate bond labelled as a covalent bond.
Hydrogen bonds labelled on line between bases.
Boxes labelled as nitrogenous bases.
Complementary base pairing/A-T/G-C.
5' - 3' linkages correctly shown; no label required.
A verified official answer image is still needed because this answer requires diagram/spatial placement.