Which of the following is a true statement about triplet codes based on the material?

• A. Sets of three nucleobases form a Triplet code.
• B. Each triplet codes a unique amino acid.
• C. Triplet codes are not used in biology.
• D. CCC and CCT code for glycine.

Answer: (D)

Triplet codes are built from sets of three nucleotides that form codons, the units that specify which amino acid to add during protein synthesis. This means three nucleobases indeed make a triplet code. But not every triplet maps to a unique amino acid, because many codons can encode the same amino acid, a feature known as degeneracy in the genetic code. It’s also not true that triplet codes aren’t used in biology. For the glycine statement, glycine is encoded by codons that start with G (for example GGU, GGC, GGA, GGG), not by triplets like CCC or CCT.