The diagram below depicts a segment of chromosomal DNA containing a highly trans
ID: 163286 • Letter: T
Question
The diagram below depicts a segment of chromosomal DNA containing a highly transcribed gene with a single intron. If we were able to isolate this segment of DNA while it was being transcribed and examine it by electron microscopy, which of the transcription patterns shown below would you expect to see? Why would you not expect to see the other patterns? [As you saw in class, each black circle represent an RNA polymerase and the wiggly lines coming off the circles represent the RNA being made.] Where do you think the promoter for this gene is located? Mark location on the diagram above. Assume that the DNA in the electron micrograph is also oriented the diagram same way as in the cartoon diagram above.)Explanation / Answer
Introns are the untranscribed and interrupted segments present in the DNA. As in the given question intron is present in the middle of the gene, so that portion will be untranscribed depicting promoter region is present in the terminal region (5') of the gene. So the expected pattern is (a)