Question

A DNA strand has the following sequence: 5’-TACGTTACG-3’. What is the mRNA complement that will he generate from this DNA template through transcription?
A. 5’- ATGCAATGC-3’
B. 3’- ATGCAATGC-5’
C. 5’-AUGCAAUGC-3’
D. 3’-AUGCAAUGC-5’
E. 3’-ATTCAATGC-5’

Answer 1

Hint: The messenger RNA (mRNA) is the single stranded intermediate RNA molecule. The mRNA is derived from the DNA by the process which is approximately similar to the process of DNA replication, where one parent DNA strand serves as template for the synthesis of new daughter DNA strand.

Complete answer: The process where DNA gives rise to RNA is called transcription which involves the formation of RNA strand on the DNA template,
There is a specific point at which the unwinding of DNA and transcription starts. Here only one of the two strands of DNA gives rise to RNA. This reaction is catalyzed by the enzyme RNA polymerase and it also requires the building blocks- A, U, G and C as their corresponding nucleotide forms.
The base sequence in the DNA strand decides the base sequence in RNA and thus the information in DNA is transcribed to RNA. The building blocks i.e. the free rna nucleotides align themselves and form the complementary RNA as per the base pairing rule i.e. A (Adenine) forms hydrogen bonds with U (Uracil) and G (Guanine) pairs with C (Cytosine).
In eukaryotes, three different RNA polymerase enzymes –I, II and III, catalyze the synthesis of ribosomal RNA, messenger RNA and transfer RNA. But in prokaryotes all these functions are performed by a single RNA polymerase.
So, a DNA strand that has the following sequence: 5’-TACGTTACG-3’will generate mRNA with the following sequence: 3’-AUGCAAUGC-5’.
So, the correct answer is “Option D”.

Note: The information in the DNA in the coded in the form of base sequences is transmitted to RNA. Several molecules of RNA that are released from DNA template are given rise by a single molecule of DNA.