試題詳解

39. There are 45 different kinds tRNA (anticodons) available to serve as amino acid carriers, but there are 64 mRNA codons. Why aren't the tRNA anticodons and mRNA codons equal in number?
(A) The reason is that the third base pair on the tRNA allows some flexibility (wobble); thus, some tRNA anticodons can recognize more than one mRNA codon.
(B) The reason is that some tRNA anticodons can misread some of the mRNA codons, which creates a "wobble" in the tRNA anticodons that can be repaired by RNA repair enzymes.
(C) The reason is that the third base pair on the mRNA codon allows some flexibility (wobble); thus, some tRNA anticodons can recognize more than one mRNA codon.
(D) The reason is that the tRNA has the flexibility to choose which mRNA codons are necessary for building the polypeptide chain.
(E) This broader recognition occurs because of the nonstandard pairing between bases in the wobble position corresponding to the 3' base in the mRNA and the complementary 5′ base in the tRNA anticodon.