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Separate Biology · Paper 2 · Higher Tier only · B6

Higher: from DNA to a protein

Key ideas1 of 3

Complementary strands

The two strands of DNA have complementary bases. A on one strand pairs with T on the other, and C pairs with G. This means the sequence on one strand determines the corresponding sequence on the opposite strand. Keep corresponding positions lined up when completing a diagram. These are DNA base-pairing rules; you do not need detailed structures of the molecules involved in protein synthesis for this course.

Aligned complementary DNA bases: A opposite T, C opposite G, T opposite A, G opposite C.

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Practice, downloads and sources

Daily 5 · Exam practice · Revision sheet ↓

Higher Tier only · B6. Use alongside the shared B6 lessons.

AQA GCSE Biology 8461 · 4.6.1.5 (HT only). Original notes, questions and diagrams. Models are simplified; teaching data are illustrative.