Comparison of a single-stranded RNA and a double-stranded DNA with their corresponding nucleobases. (Image: Wikimedia Commons, CC SA 3.0) The most common type of base pairing is the Watson-Crick base ...

This image depicts the chemical structure of cytosine. It shows a hexagonal ring with nitrogen atoms at positions 1 and 3, and a primary amine group attached to carbon 4. The two remaining positions ...

In living organisms today, complex molecules like RNA and DNA are constructed with the help of enzymes. So how did these molecules form before life (and enzymes) existed? Why did some molecules end up ...

A giant impact on the early Earth could have brought the building blocks of RNA to our planet, which new research suggests ...