Humber Admissions Practice Test

Uracil is the base that is found in RNA but not in DNA. In RNA, uracil replaces thymine, which is one of the four nitrogenous bases present in DNA. The other bases found in both RNA and DNA include adenine, guanine, and cytosine. The structural difference between thymine and uracil is that thymine has a methyl group that uracil lacks, which contributes to the distinct properties and functions of RNA compared to DNA. The presence of uracil in RNA is significant for several reasons, such as RNA's role in protein synthesis and its often less stable structure compared to DNA. This distinction is critical in understanding the molecular biology of nucleic acids and their functions within living cells.