Question

Choose the correct answer from the alternatives given :
Identify A, B, C and D in the given diagram of mRNA.

• A. A Methylated Cap, B Initiation codon, C Termination codon, D - Poly A tail codon
• B. A - Poly A tail, B Termination codon, C Initiation codon, D Methylated cap
• C. A Methylated cap, B Non-coding region, C Coding region, D - Poly A tail region
• D. A Methylated cap, B Coding region, C - Non-coding region, D - Poly A tail region

Answer 1

The correct option is C A Methylated cap, B Non-coding region, C Coding region, D - Poly A tail region

The given image is of mRNA. In the given image, A is methylated cap. An mRNA has methylated region at the 5' terminus. It functions as a cap for attachment with ribosome. Cap is followed by an initiation codon (AUG) either immediate!y or after a small non-coding leader region. Hence, B is noncoding region. It is then followed by C, that is coding region. This coding region is then followed by termination codons (UAA, UAG or UGA). After termination codon, there is a small non-coding trailer region and poly A tail at the 3' terminus. Hence, D is poly A tail region. Cap at 5' end and poly-A tail at 3' end protect mRNA from enzymatic breakage.

Thus, the correct answer is 'A Methylated cap, B Non-coding region, C Coding region, D Poly A tail region.'