There are 61 mRNA codons that specify an amino acid, but only 45 tRNAs. This is best explained by the fact that
A) some tRNAs have anticodons that recognize four or more different codons.
B) the rules for base pairing between the third base of a codon and tRNA are flexible.
C) many codons are never used, so the tRNAs that recognize them are dispensable.
D) the DNA codes for all 61 tRNAs but some are then destroyed.
E) competitive exclusion forces some tRNAs to be destroyed by nucleases.

Question

Quizplus · Accepted Answer

The phenomenon described is due to the "wobble" hypothesis, which explains that the base pairing rules between the third base of a codon and the anticodon of tRNA are less stringent, allowing a single tRNA molecule to recognize and bind to more than one codon.

There Are 61 MRNA Codons That Specify an Amino Acid