Final answer:
The amino acid tyrosine (Tyr) is encoded by two mRNA codons: UAU and UAC, as per the genetic code chart.
Step-by-step explanation:
The codons that code for the amino acid tyrosine (Tyr) are identified through a genetic code chart or table. Tyrosine is abbreviated as Tyr, and according to the genetic code, it has two codons that correspond to it. These codons are UAU (uracil-adenine-uracil) and UAC (uracil-adenine-cytosine). Therefore, during the process of protein synthesis, when either of these codons are present in the mRNA transcript, the amino acid added to the growing polypeptide chain will be tyrosine.