How many possible codons are there in the genetic code?

How many possible codons are there in the genetic code?

• A. 64
• B. 20
• C. 4
• D. 100

Answer: (A)

Codons are triplets of nucleotides, and there are four options for each position (A, U, C, G in RNA). With three positions, the total number of possible triplets is 4 × 4 × 4 = 64. These 64 codons form the genetic code used during translation. Among them, 61 codons specify amino acids (with redundancy so multiple codons can code for the same amino acid), and 3 codons are stop signals that terminate translation. So the full set of possible codons is 64. The other numbers in the options relate to different aspects: 20 is the number of amino acids, 4 is the number of nucleotides, and 100 isn’t related to codon count.

Codons are triplets of nucleotides, and there are four options for each position (A, U, C, G in RNA). With three positions, the total number of possible triplets is 4 × 4 × 4 = 64. These 64 codons form the genetic code used during translation. Among them, 61 codons specify amino acids (with redundancy so multiple codons can code for the same amino acid), and 3 codons are stop signals that terminate translation. So the full set of possible codons is 64. The other numbers in the options relate to different aspects: 20 is the number of amino acids, 4 is the number of nucleotides, and 100 isn’t related to codon count.