In Rna Thymine Is Replaced by?

DNA (top) includes thymine (red); in RNA (bottom), thymine is replaced with uracil (yellow).

What substitutes for thymine in RNA?

In RNA, however, a base called uracil (U) replaces thymine (T) as the complementary nucleotide to adenine (Figure 3).

What is replaced by U in RNA?

Uracil is a nucleotide, much like adenine, guanine, thymine, and cytosine, which are the building blocks of DNA, except uracil replaces thymine in RNA. So uracil is the nucleotide that is found almost exclusively in RNA.