Question

Use the double-stranded DNA molecule below to answer the following questions. The first pair of nucleotides (bolded) contains the start point of transcription.

5'-ATGTCAGGTACGCCACAT-3'

3'-TACAGTCCATGCGGTGTA-5

Which of the following is the correct mRNA produced from the transcription of this DNA molecule?

1. 3'-UACAGUCCAUGAGGUGUA-5'
2. 5'-AUGUCAGGUACGCCACAU-3'
3. 3'-UACAGUCCAUGCGGUACA-5'
4. 5'-AUGUGGAGUACCUGACAU-3

Answer 1

The correct answer is 2. 5'-AUGUCAGGUACGCCACAU-3'

Step-by-step explanation:

The template strand for transcription is 3'-TACAGTCCATGCGGTGTA-5 and RNA polymerase will add complementary mRNA sequence against this strand in the opposite direction i.e., 5' to 3' direction.

In RNA, A(adenine) makes complementary base pairing with U(uracil), not with T(thymine) and the rest of the base-pairing is same as in DNA. Therefore the correct mRNA produced from the transcription of this DNA molecule by the help of RNA polymerase is 5'-AUGUCAGGUACGCCACAU-3'.

Then this mRNA sequence will be used by ribosomes to synthesize proteins during the translation process.