Conversation so far:
what are the four bases of dna and rna
The bases A, G, C, and T are found in DNA while A, G, C, and U are found in RNA.
what is the proper term for the bases of dna and rna
Nucleobases, also known as nitrogenous bases or often simply bases, are nitrogen-containing biological compounds that form nucleosides.
are thyamine and uracil almost identical
Thymine and uracil are identical except that T includes a methyl group that U lacks.

Question: do analogues of the bases exist
Self-contained rewrite: do analogues of the nucleobases exist