I am taking a biochemistry lab class, we work with plasmids, ligating protein DNA sequences to clone the DNA and then performing analysis on the protein (a beta lactamase) is most of what we do during lab sessions. In the image is a quiz question I got wrong, can someone please explain this to me? I have always thought that the coding strand is written on top 5' - 3', is the convention different for some niche or something? We work with plasmids such as the pET-30a(+)

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    $\begingroup$ The question you reproduce asks about something it calls the “template strand”. Your question asks about something you call the “coding strand”. As my answers on this site make clear, neither of these terms have any intrinsic meaning (for me at least) in regard to DNA. However you should try to answer the question as worded. The only strand of a gene that is a template is what I call the antisense strand — that which is the reverse complement of the mRNA. I suspect that you equate it to the “coding” strand, whereas I believe that people who use this term equate it to the “non-coding” strand. $\endgroup$
    – David
    May 3 at 19:01
  • $\begingroup$ This is the link to my answer on the terminology of strands. I do sympathize with your predicament. MCQs are one of the worst methods of assessment ever devised. They are frequently ambiguous and tend to test things that people think are easy to test rather than things that are most important. $\endgroup$
    – David
    May 4 at 14:56


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