This means to order them as they appear in the alphabet. When sorting words in to alphabetical order, we look at the first letter of the word. That is because 'c' comes before 'd' in the alphabet.

In all forms of life on earth, genetic information is composed of a four-letter alphabet—the nucleotides G, C, A, and T, which form the base pairs G-C and A-T. But three years ago, chemistry professor ...