The laws governing degeneration of the genetic code are discussed below. Of fundamental importance in this context is the classification of the amino acids into groups on the basis of the physicochemical behaviour of their residues. From this, it is possible to formulate arithmetic relationships between the number of amino acids in the same group and the number of coding triplets.It is found that the degeneration of the genetic code obeys certain laws, the reasons for this being related to the (...) number and the qualitative properties of the amino acids and triplets. The fact that the three bases of a coding triplet have different priorities must also be a critical factor. (shrink)