This is a model of translation in which the genetic code carried on mrna is used to assemble amino acids into a polypeptide. a codon is a sequence of three nucleotides that codes for a particular amino acid. using the model, where would you find a codon?
a) on mrna
b) on trna
c) attached to the ribosome
d) attached to the polypeptide

I found the codon in mRNA.

Explanation:

Codon is a three nucleotide sequence which is present in mRNA. From each codon sequence one amino acid can be translated.

Example : AUG ⇒ methionine

It is also possible that two or more codon can code one type of amino acid.

Example : valine can be coded by 6 nucleotide.

tRNA  carry amino acids. It also contains the anticodon arm which is dimerizes with specific codon.

All process occurs when two subunits of ribosome are attached in mRNA.

Polypeptide chain is formed from the peptide bond formation in between two amino acid.

a polymer is a chainlike molecule made up of small molecular units. these small molecular units are called monomers. monomers of polymer can be joined together either naturally or synthetically.  

the answer is d (apex) good luck : ))