# Genetics

posted by
**Anonymous**
.

If there's 4 nucleotides, what is the probability to get a start codon ?

If I understand correctly; a codon = 3 nucleotides, so there's 2 possible combinations with 4 nucleotides (AAAX and XAAA), of the 64 possible codons, there's only 1 start codon. So 2 possible combinations * 1/64 = 1/32. But I'm not sure about this.