Question

question 7 of 12
the segment of dna is unwound in preparation for transcription.
5 gtgctggta 3
3 cacgaccat 5 ← template strand

identify the mrna transcript that would be produced from this dna sequence.
o 5 gugcuggua 3
o 5 acaucaacg 3
o 5 cacgaccau 3
o 5 gtgctggta 3
o 5 cacgaccat 3

Explanation:

Step1: Recall base - pairing rules for transcription

In transcription, DNA is used as a template to make mRNA. The base - pairing rules are: A (adenine) in DNA pairs with U (uracil) in mRNA, T (thymine) in DNA pairs with A in mRNA, G (guanine) pairs with C (cytosine), and C pairs with G. The mRNA is synthesized in the 5' to 3' direction using the 3' to 5' DNA template strand.

Step2: Transcribe the given DNA template strand

The DNA template strand is 3' CACGACCAT 5'.
For the first base C in the DNA template strand, the corresponding base in mRNA is G.
For A in the DNA template strand, the corresponding base in mRNA is U.
For C in the DNA template strand, the corresponding base in mRNA is G.
For G in the DNA template strand, the corresponding base in mRNA is C.
For A in the DNA template strand, the corresponding base in mRNA is U.
For C in the DNA template strand, the corresponding base in mRNA is G.
For C in the DNA template strand, the corresponding base in mRNA is G.
For A in the DNA template strand, the corresponding base in mRNA is U.
For T in the DNA template strand, the corresponding base in mRNA is A.
The resulting mRNA sequence is 5' GUGCUGGUA 3'.

Answer:

5' GUGCUGGUA 3'