Science / Biology / Purine: One of the groups of nitrogenous bases that are part of a nucleotide. Purines are adenine and guanine, and are double-ring structures.
Science / Biology / Barr Body: Inactivated X-chromosome in mammalian females. Although inactivated, the Barr body is replicated prior to cell division and thus is passed on to all descendant cells of the embryonic cell that had one MORE
Science / Biology / Guanine: One of the nitrogenous bases in nucleic acids, guanine is one of the two purine bases. MORE