Nitrogenous bases are the parts of RNA and DNA that are involved in pairing up (see also base pairs). These include cytosine, guanine, adenine, thymine (DNA) and uracil (RNA).
... Mary's (Whitechapel Road) tube station[?] South Acton tube station[?] South Kentish Town tube station[?] Swiss Cottage (Metropolitan Line) tube station[?] Tower of ...