Universal Genetic Code (Evolution) — Evidence & Examples

There are 4 possible codons, and multiple codons are needed to call down one amino acid

There are 16 possible codons, and two codons are needed to call down one amino acid, but some codon combinations are redundant

There are 20 possible codons, and each amino acid has one corresponding codon

There are 64 possible codons, and each amino acid has multiple corresponding codons