AP BIOLOGY

Detailed explanation-1: -The correct option is D codons. The triplets of nitrogenous bases in DNA that code for amino acids are called codons. There are 64 codons, 61 of which code for different amino acids. The remaining three codons are stop/termination codons, which act as stop signals for protein synthesis.

Detailed explanation-2: -mRNA is composed of bases triplets, represented by a three letter code for a specific amino acid, e.g. AGC = serine. This three letter code is called a codon that is read from the 5’ to the 3’ end.

Detailed explanation-3: -Codon: A codon is the triplet of a set of bases (or nucleotides) in DNA that codes for an amino acid. The triple base complement for a codon is called an anticodon; By convention, triplets in mRNA are called codons, and triplets in tRNA are called anticodons. These codons are translated into protein sequences.

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.

Detailed explanation-5: -A codon is a nucleotide triplet, it is formed of a set of three nucleotides and hence it is called a triplet codon. DNA and mRNA contain only four kinds of nucleotides to code for the 20 proteinogenic amino acids.