Final answer:
The term 'intron' is least related to tRNA, anticodon, and polypeptide, as it does not directly participate in the protein synthesis process like the other terms do.
Step-by-step explanation:
The term intron is the LEAST closely related to the other terms listed. A, B, and D are all closely related to the process of translation in protein synthesis. tRNA (transfer RNA), anticodon, and polypeptide chains are all directly involved in the synthesis of proteins, whereas introns are not involved in the synthesis itself. In the process, tRNA molecules carry amino acids to the ribosome, where they are added to a growing polypeptide chain. Each tRNA has an anticodon that pairs with a complementary codon on the mRNA (messenger molecule that provides the code for protein synthesis). Introns, on the other hand, are non-coding sequences found in the initial RNA transcript, or pre-mRNA; they are spliced out before the mRNA is translated into a protein.