AP BIOLOGY

Detailed explanation-1: -Cells decode mRNAs by reading their nucleotides in groups of three, called codons. Here are some features of codons: Most codons specify an amino acid.

Detailed explanation-2: -Three codons, UAA, UAG, and UGA, are known as stop codons as they stop the process of translation. If this is a mutation as a stop codon and its finishes prematurely it is called an amber codon. AUG is also known as a start codon, as it initiates the process of translation.

Detailed explanation-3: -There are 3 STOP codons in the genetic code-UAG, UAA, and UGA. These codons signal the end of the polypeptide chain during translation. These codons are also known as nonsense codons or termination codons as they do not code for an amino acid.

Detailed explanation-4: -The three-letter nature of codons means that the four nucleotides found in mRNA-A, U, G, and C-can produce a total of 64 different combinations. Of these 64 codons, 61 represent amino acids, and the remaining three represent stop signals, which trigger the end of protein synthesis.