Uracil - Wikipedia
Apparently, either there was no evolutionary pressure to replace uracil in RNA with the more complex thymine, or uracil has some chemical property that is useful in RNA, which thymine lacks.

Uracil | C4H4N2O2 | CID 1174 - PubChem
Uracil is a common and naturally occurring pyrimidine nucleobase in which the pyrimidine ring is substituted with two oxo groups at positions 2 and 4. Found in RNA, it base pairs with adenine and replaces thymine during DNA transcription.

Uracil - National Human Genome Research Institute
Uracil (U) is one of the four nucleotide bases in RNA, with the other three being adenine (A), cytosine (C) and guanine (G). In RNA, uracil pairs with adenine. In a DNA molecule, the nucleotide thymine (T) is used in place of uracil.

Uracil | Nucleobase, Nucleoside & DNA | Britannica
Uracil, a colourless, crystalline organic compound of the pyrimidine family that occurs as a component of ribonucleic acid (RNA), a molecule involved in the transmission of hereditary characteristics.

Uracil: Structure, Synthesis and Uses - allen.in
Uracil is one of the four nucleobases found in RNA (ribonucleic acid), which is a type of genetic material present in cells. Learn more about uracil here.

Uracil | 66-22-8 - ChemicalBook
Uracil is an organic alkali, and is one of the four major bases in RNA. It is a major component of the pyrimidine composition in ribonucleic acid (RNA) as well as in various kinds of uridines.

The Chemistry of Uracil: A Deep Dive - numberanalytics.com
Uracil is one of the four nucleobases found in the nucleic acid of RNA. It plays a crucial role in the structure and function of RNA, and its unique chemical properties make it an important molecule to study.

Uracil - New World Encyclopedia
Uracil is used in animals and plants to help carry out the synthesis of many enzymes necessary for cell function through bonding with riboses and phosphates (Garrett and Grisham). Uracil serves as an allosteric regulator and coenzyme for reactions in the human body and in plants (Brown 1998).

Uracil - Wikiwand
Uracil is one of the four nucleotide bases in the nucleic acid RNA. The others are adenine (A), cytosine (C), and guanine (G). In RNA, uracil binds to adenine v...

Why Uracil is Only Present in RNA? - GeeksforGeeks
Uracil is one of the four nitrogenous bases present in RNA, the other three being adenine, guanine, and cytosine. Unlike DNA, RNA contains uracil in place of thymine. This difference between DNA and RNA is important as it affects their properties and functions.