In this chapter, we focused on the analysis of genomes, transcriptomes, and proteomes and considered important applications and findings from these endeavors. 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, what answers would you propose to the following fundamental questions?

How have microarrays demonstrated that, although all cells of an organism have the same genome, some genes are expressed in almost all cells, whereas other genes show cell- and tissue-specific expression?

Video transcript

Welcome back. Here's our next question which of the following statements about micro array technology is true. So let's look at our answer choices. Thinking about what microwave technology is noticing that choice D. Is. All options are correct. So keep in mind that it may be that all of our statements are true. So let's recall from our content video, what micro ray technology is. Put a little definition here. And it's a tool used to detect the expression of thousands of genes at the same time. And done by printing thousands of tiny spots and defined positions that contain known DNA sequences on a microscope slide. So you have this little slide, all these spots and you know which DNA sequences are in which places. So then the way that helps you detect the expression of genes is that you have a sample with M. RNA molecules and you want to identify which of those genes in your micro ray has been transcribed into M. RNA molecules in your sample. So to do that, you first synthesized the complementary D. N. A. To your M. R. N. A. And your samples and that C. D. N. A. That complementary DNA is labeled with a fluorescent marker. You then take your sample that now has complementary DNA to your M. RNA. That was in your original sample, wash it over your micro ray. Those strands that are complementary to jeans on your micro ray will bind to them hybridize with the micro ray. Um and due to that fluorescent marker, you'll be able to see which those sequences are since you know the locations of the different DNA sequences. Finally, you'll wash off any strands of from your sample that haven't bound to sequences on your micro array. So let's look at our answer choices. Keeping all that in mind. Choice A says it involves hybridization between the nuclear nuclear acid strands. And we're going to mark that correct. Not selected yet. Since we have that, all options are correct. Choice. And yes it does. You're gonna look for hybridization between the complementary DNA and your sample and the DNA in your micro array, choice B says non specific binding sequences are washed out. And that is correct. That's your last step there. When you wash off anything in your sample that hasn't bound to your micro array. And finally, choice. See the samples are labeled with fluorescent dyes. That is correct. That's how you're going to identify where you have molecules from your sample that volunteer micro ray so we can see that. Our answer here is going to be choice D. All options are correct. So, again, which of the following statements about micro ray technology is true choice D All options are correct. See you in the next video