Question

On which strand of DNA, m-RNA is constructed?
a) Strand oriented as 5'→4'
b) Strand oriented as 3'→5'
c) Both the strands
d) Any one strand

Answer 1

Answer:

b) Strand oriented as 3'→5'

Explanation:

mRNA is constructed on the strand oriented as 3'→5'. This strand that has the polarity from 3' end to 5' end is called template stand while the polarity from 5' end to 3' is referred to as the coding strand.  

DNA is double-stranded in which only one strand is transcribed whereas coding strand does not transcribe and codes for the protein of a gene.

Answer 2

The correct answer is b) Strand oriented as 3'→5'.

Explanation:

• The process of Transcription, that is, the conversion of DNA (Deoxyribonucleic acid) to mRNA( messenger Ribonucleic Acid) sequence, is carried out by the enzyme called DNA-dependent RNA polymerase.
• The enzyme synthesises the mRNA in the 5'→3' direction.
• The sequence of the mRNA is complementary to the DNA sequence.
• So, it scans the DNA in the opposite orientation, that is, in the 3'→5' direction. This strand of the DNA is called the Template Strand and the other strand is called the Coding Strand.