Question

The sequence of nitrogenous bases in a segment of a coding strand of DNA is 
5' – AATGCTAGGCAC – 3'. Choose the option that shows the correct sequence of nitrogenous bases in the mRNA transcribed by the DNA.

• A. 5' – UUACGAACCGAG – 3'
• B. 5' – AAUGCUAGGCAC – 3'
• C. 5' – UUAACGAACCGUG – 3'
• D. 5' – AACGUAGGCAGC – 3'

Hint:

mRNA is identical to the coding strand (except T → U). Transcription uses the template strand.

Answer 1

The Correct Option is B

Step 1: The coding strand is given. So, the mRNA will be complementary to the template strand and identical to the coding strand (except U replaces T).
Step 2: Replace each T with U in the coding strand: AATGCTAGGCAC → AAUGCUAGGCAC.