Linked from
The 8 pages that link to Thymine, each with the reason it gives.
RNACompared with: RNA usually uses uracil in place of thymine.
AdenineCompared with: Thymine is adenine’s DNA partner and is generally replaced by uracil in RNA.
PyrimidineBroader topic: Thymine distinguishes DNA’s standard bases from those used in RNA.
UracilCompared with: DNA generally uses thymine where RNA uses uracil.
ThymidineRelated: Thymine is the base attached to deoxyribose in thymidine.