Final answer:
The sequence of bases on tRNA is determined by the sequence of bases on mRNA through the process of translation. Based on the given mRNA sequence 'gcu', the corresponding tRNA sequence will be 'cga'. Therefore, the correct answer is (a) cga.
Step-by-step explanation:
The sequence of bases on tRNA is determined by the sequence of bases on mRNA through the process of translation. In translation, each three-base sequence on mRNA, known as a codon, corresponds to a specific amino acid. The tRNA molecule carries the corresponding amino acid to the ribosome, where it binds to the codon on the mRNA.
Based on the given mRNA sequence 'gcu', the corresponding tRNA sequence will be 'cga'.
Therefore, the correct answer is (a) cga.