Question

During transcription, mRNA is produced from the antisense strand of DNA. This means that the mRNA will match the
A. Sense strand of DNA, substituting uracil for thymine.
B. Sense strands of DNA, substituting thymine for uracil.
C. Antisense strand of DNA, substituting thymine for uracil.
D. Antisense strand of DNA, substituting uracil for thymine.

Answer 1

Answer: The correct answer is -

A. Sense strand of DNA, substituting uracil for thymine.

Explanation:

Transcription is a process of formation of mRNA (messenger RNA) using a DNA template with the help of enzyme RNA polymerase.

In this process, ribonucleotides are added by RNA polymerase in 5' to 3' direction (that is antiparallel to the direction of template DNA) in a complementary manner.

For Adenine, uracil is added and for Cytosine, Guanine is added in mRNA. This produces the mRNA transcript matching the sense strand of DNA (that is complementary to antisense or template DNA).

Thus, option A) is the right answer.

Answer 2

Answer:

The correct answer is option A. "Sense strand of DNA, substituting uracil for thymine".

Explanation:

During transcription, RNA polymerase identifies a DNA sequence called promoter and uses the antisense strand of DNA to synthesize a RNA that is complementary and antiparallel. Since the antisense strand is complementary and antiparallel to the sense strand of DNA, the RNA will match the sense strand of DNA. The only difference is that uracils substitute the thymines in the DNA, since RNA are comprised of uracils in its nucleotide sequence.