Question

If a tRNA molecule has a anticodon which reads GCU, what was the codon of the mRNA molecule ?

Answer 1

CGA because in rna Uracil is replaced by Thymine therefor Adenine pairs with Uracil

Answer 2

The anti-codons present on the tRNA binds to the codons present on the mRNA. tRNA carries only one type of amino acid and recognize only specific codon.

So, If a tRNA molecule has an anti-codon that reads GCU, it will bind to a CGA codon of the mRNA molecule.