The 'triplet code' refers to the fact that _________.

• A. each codon consists of two nucleotides
• B. three amino acids are encoded by a single nucleotide
• C. each amino acid is specified by a sequence of three nucleotides in mRNA
• D. the genetic code is read in groups of four nucleotides

Answer: (C)

Verified step by step guidance

1. Understand that the 'triplet code' is a fundamental concept in molecular genetics describing how genetic information is translated into proteins.
2. Recall that nucleotides in mRNA are read in groups to specify amino acids during protein synthesis.
3. Recognize that each group, called a codon, consists of three nucleotides, which together code for a single amino acid.
4. Note that this triplet nature means that the genetic code is read in non-overlapping sets of three nucleotides, not two or four.
5. Therefore, the correct interpretation is that each amino acid is specified by a sequence of three nucleotides in mRNA.