The nucleotide
bases are adenine (A), guanine (G), cytosine (C), thymine (T), and uracil (U).
The bases combine with sugar to make them adenosine, guanosine, cytidine, thymidine, and uridine
repectively.
The bases can
be arranged in many different combinations and the genes in their long chains
can have trillions of different combinations.
