Question

if the anticodon of a molecule of trna has the sequence gau, what was the original dna sequence?
○ cta
○ cua
○ gat
○ cat

Explanation:

1. tRNA anticodons pair with mRNA codons via complementary base pairing: A-U, U-A, C-G, G-C. For anticodon GAU, the mRNA codon is CUA.
2. mRNA is transcribed from DNA, with RNA using U instead of DNA's T. The DNA template strand is complementary to mRNA: A pairs with T, T pairs with A, C pairs with G, G pairs with C. For mRNA CUA, the DNA template strand is GAT.
3. The original coding DNA strand (non-template) is complementary to the template strand, so it matches the mRNA sequence with U replaced by T: CTA.

Answer:

O CTA