A1.2.6—DNA as a double helix Topic Practice
A1.2.6—DNA as a double helix Topic Practice
Practise interpreting DNA double-helix structure, base pairing and evidence from models, diffraction images and molecular diagrams.
How this is tested
- identify complementary DNA base pairs, excluding uracil from double-helix pairings
- explain hydrogen bonding between paired bases and covalent bonding in the backbone
- interpret model or diffraction evidence for helical shape and antiparallel backbones