Final answer:
The correct options are A,B,D .Based on the anticodon provided (AAA), which pairs with the mRNA codon UUU, the correct tRNA amino acid complex that would bind to the A site is Phenylalanine, even though it was not listed as an option.
Step-by-step explanation:
To determine which tRNA amino acid complex will attach to the A site, we need to consider the information given about anticodons and codons.
The base-pairing rules specify that the anticodon of tRNA will pair with a complementary codon on the mRNA.
From the information provided, if the anticodon is AAA, then the mRNA codon must be UUU, which codes for the amino acid Phenylalanine.
When the ribosome reaches a nonsense codon, the polypeptide is released, so we do not consider methionine incorporation in this context.
Since the anticodon AAA will bind to the codon UUU, and not to any of the codons for the amino acids listed in the options, we infer that none of the provided options A, B, D (Arginine, Leucine, Glycine) are correct.
Thus, the correct answer is B) Phenylalanine, which was not one of the initial choices provided. There must be an issue with the question if Phenylalanine is indeed the correct answer based on the provided.
In summary, an activated tRNA that has the anticodon AAA would bind a Phenylalanine to its corresponding mRNA codon UUU in the A site of the ribosome.