What is the base that is different in RNA than in DNA?

In RNA, the base uracil is present instead of thymine, which is found in DNA. This distinction is significant because it highlights the structural and functional differences between these two types of nucleic acids.

Uracil pairs with adenine during RNA synthesis and plays a crucial role in the processes of transcription and translation, which are key steps in gene expression. The absence of thymine in RNA is also linked to the chemical properties of the molecules; uracil is more reactive than thymine, allowing RNA to be more versatile and stable for its often temporary roles within the cell, such as coding, decoding, regulation, and expression of genes.

Thus, the presence of uracil in RNA instead of thymine is a fundamental difference that influences not just the stability of the nucleic acid but also its function in the cell.