Question

What will be the codons in m-RNA if the DNA codes are ATG-CAG?

• A. TAC-GTC
• B. UAC-GUC
• C. UCA-TUA
• D. TCA-GTC

Answer 1

Answer: (B)

UAC-GUC

We know that Thymine (T) always pairs with adenine (A) and Guanine (G) with cytosine (C). RNA has uracil (U) in place of thymine therefore; adenine pairs with uracil in RNA. So, the mRNA codon for ATG-CAG code will be UAC-GUC which makes option B correct.

Options A, C and D are incorrect as thymine is absent in RNA and the sequences in these options do not follow the complementary base pairing mentioned.

Therefore, the correct answer is option B.