Questions: Liam's DNA (affected) coding strand 5'- C T A T G T G C T T A A T C T A C C - 3' 3'- G A T A C A C G A A T T A G A T G G - 5' template strand Q6: The above DNA sequence is being transcribed by an RNA polymerase (red square). The premature stop codon mutation in Liam's DNA is indicated in blue. What will the RNA polymerase do when it reaches the nucleotides encoding for the premature stop codon? It will: A. stop when it reaches the first nucleotide encoding for the premature stop codon. B. stop when it reaches the last nucleotide encoding for the premature stop codon. C. not be affected by this base change and will continue to read through the change in the DNA.

The answer is C: not be affected by this base change and will continue to read through the change in the DNA.

Explanation:

1. Understanding Transcription: During transcription, RNA polymerase reads the template strand of DNA to synthesize a complementary RNA strand. The RNA polymerase does not recognize stop codons; it simply transcribes the DNA sequence into RNA.

2. Role of Stop Codons: Stop codons are relevant during the translation process, where the ribosome reads the mRNA to synthesize proteins. A premature stop codon in mRNA can lead to truncated proteins, but it does not affect the transcription process itself.

3. Options Analysis:

   • Option A: This suggests that RNA polymerase would stop at the first nucleotide of the stop codon, which is incorrect because RNA polymerase does not recognize stop codons.
   • Option B: This suggests that RNA polymerase would stop at the last nucleotide of the stop codon, which is also incorrect for the same reason as above.
   • Option C: This is correct because RNA polymerase will continue transcribing the DNA into RNA regardless of the presence of a stop codon.

In summary, the presence of a premature stop codon in the DNA sequence does not affect the transcription process carried out by RNA polymerase.