In this chapter, we focused on how eukaryotic gene expression is regulated posttranscriptionally. At the same time, we found many opportunities to consider the methods and reasoning by which much of this information was acquired. From the explanations given in the chapter:

How do we know that microRNAs negatively regulate target mRNAs?

Video transcript

Hello everyone. Let's look at our next question. The M I R N. A. S. Are products of M. I. RNA genes and are transcribed in the nucleus. How do they differ from M. R. N. S. So M I R M I R nis or Micro Arnie's are short R N. A sequences that are non coding and are important for gene regulation. So with that in mind let's look at our answer choices. And let's recall that the M I R N. A. S are transcribed and processed in the same way as M. R. And S. So with that in mind let's look at our answer choices twice A. Says they do not contain introns. Well, again we mentioned that these M. I R N. A. S are processed in the same way as M R. And S. So they have intrinsic get spliced out just as with the M R N. A. S. So let's cross that out. That's not an answer choice. B says they have no five prime cap. Again we know that they are transcribed and processed in the same way. So they do have five prime cap. So B is not our answer. And for the same reason Joyce. See they lack a poly a tail also not our answer. So we're down to choice D. They have self complementary sequences and this is our correct answer. The micro RNA is have these self complementary sequences and that causes them to form these hairpin structures and that's key to their role in helping to regulate the expression of M R N. E. S. So again the M i r n a s. How do they differ from M r n A. S. Choice D. They have self complementary sequences, See you in the next video.