Final answer:
A codon refers to a sequence on mRNA that codes for a specific amino acid, while an anticodon on tRNA complements and matches with the codon to add the correct amino acid during protein synthesis.
Step-by-step explanation:
The question is asking for the relationship between a codon on mRNA and another component involved in protein synthesis. In such analogies, we're considering how parts of the cell's protein-synthesis machinery relate to one another. In this context, the correct answer is: codon: mRNA :: anticodon: tRNA. This is because a codon is a sequence of three nucleotides on mRNA that corresponds to a specific amino acid or stop signal during protein synthesis, while an anticodon is a sequence of three nucleotides on tRNA that is complementary to a codon on mRNA, enabling it to deliver the correct amino acid to the site of protein synthesis.