Question

If the base sequences of the strand of DNA is CAT TAG CAT CAT GAC, what will be base sequence of complementary RNA strand?

• A. TAG ATG GTA GAT GAT CTS
• B. GUA AUC GUA GUA CUG
• C. GTA ACC GAT GAT GAT CAT
• D. GTA ATG ATG GUA CUG

Answer 1

Answer: (B)

When the DNA template is used to form the RNA with the help of an enzyme called DNA-dependent-RNA Polymerase, the process is called transcription. In this process, the complementary base pair rule is applied which says that adenine pairs with thymine and vice-versa through two hydrogen bonds and cytosine pairs with guanine through three hydrogen bonds. However, in RNA, there is no thymine. Instead of thymine, uracil is present. So, when DNA is transcribed, wherever adenine is present on DNA, uracil will be added on RNA. So, on applying the base pair complementary rule, CAT TAG CAT CAT GAC on DNA will give GUA AUC GUA GUA CUG on the RNA.

Hence, the correct answer is 'GUA AUC GUA GUA CUG'