AP BIOLOGY

Detailed explanation-1: -Three of these codons are stop codons: UAA, UAG, and UGA. The remaining 61 codons encode 20 amino acids. Out of these 61 codons, the codon AUG (which encodes the amino acid methionine) also serves as a the start signal (start codon) for translation initiation.

Detailed explanation-2: -Three “stop” codons mark the end of a protein. One “start” codon, AUG, marks the beginning of a protein and also encodes the amino acid methionine.