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Daily Problem·Wednesday, 21 January 2026Back to today

Q1 — DNA bases (1 mark)

GCSE · Combined Science · Edexcel · CB3Genetics

Question

Which base in DNA pairs with adenine?

A) Cytosine B) Guanine C) Thymine D) Uracil

Mark scheme (1 mark): C — Thymine. (Uracil is in RNA, not DNA — common distractor.)

1 mark · take your time before peeking.

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Generated by TopMyGrade AI · cross-check official sources before relying on the mark-scheme phrasing.