How many codons are possible in a system in which a sequence of three bases specifies a single amino acid?

Question

Quizplus · Accepted Answer

In a system where a sequence of three bases specifies a single amino acid, there are 4 different bases (adenine, cytosine, guanine, and thymine in DNA; uracil replaces thymine in RNA). Since each position in the codon can be occupied by any of the 4 bases, the total number of possible codons is 4^3 = 64.

How Many Codons Are Possible in a System in Which