Question

AGGTATCCCAT is a sequence from the coding strand of a gene. What will be the corresponding sequence of the transcribed mRNA?

• A. UCCAUAGCGUA
• B. UGGTUTCGCAT
• C. ACCUAUGCGAU
• D. AGGUAUCCCAU

Answer 1

The correct option is D AGGUAUCCCAU

Nitrogen bases in DNA and RNA
1) The nitrogenous bases are of 2 types - purines (adenine and guanine) and pyrimidines (cytosine, thymine and uracil).
2) RNA consists of adenine and guanine as purines.
3) RNA differs from DNA in terms of the pyrimidines that it possesses. It consists of cytosine and uracil in place of thymine. It does not contain thymine, unlike DNA.

Coding and non-coding strands of DNA
In DNA, the 5’-3’ strand is known as the coding strand. It is not used as a template for mRNA synthesis and is hence also known as the non-template strand.
The 3’-5’ strand is complementary to the coding strand and is used as a template for mRNA synthesis. It is known as the non-coding or template strand.

Sequence of template strand
The given sequence for a particular region of the coding strand is -
AGGTATCCCAT.
As the template strand is complementary to the coding strand, the sequence, the sequence of the template strand will be - TCCATAGGGTA.

Sequence of mRNA molecule
The sequence of the mRNA strand will be complementary to the sequence TCCATAGGGTA of the template strand.
As in the mRNA uracil will replace thymine, the sequence on the mRNA strand will be - AGGUAUCCCAU

Final answer
(A) AGGUAUCCCAU